HomeMy WebLinkAboutExterior Building Materials-~-off
Indigo -Carmel, IN
Exterior Material Percentages
1-30-09
N S E W TOTAL
BRICK (Light) 3384 2211 2119 2025 9739 23.2%
BRICK (Dark) 5098 5471 455 916 11940 28.4%
LIMESTONE 1564 1485 632 0 3681 8.8%
EIFS (Exposed) 1417 2295 0 0 3712 8.8%
EIFS (Hidden) 1221 1221 0 0 2442 5.8%
WINDOWS/DOORS 4163 3848 1219 1261 10491 25.0%
TOTAL 16847 16531 4425 4202 42005 100.0%
Total Masonry = 9739+11940+3681=25360=60.4%
EIFS Total = 3712+2442=6154=14.6%
\~l~^"'JJJ Acoustic
®~ SUPPLY INC
Steve Kelly
Sales Representative
skel ly@aco u sticsu pp I y. com
3t 7.872.7100x109 4t2 N. Tremont Street
317.694.0585 cell P.O. Box 22248
317.872.8110 fax Indianapolis, IN 46222-0248
a
OAK RIDGE NATIONAL LABORATORY
MANAGED BY UT-BATTELLE FOR THE DEPARTMENT OF ENERGY
Achilles Karaglozis, Ph.D.
Building Envelope Group
P.O. Box 2008
Oak Rltlge, TN 37831-6070
Telephone:1865)576-3924; Fax: 1865)574.9354
Email: kamoiozieanraloml.aov
www.oml.govlbtclmolsture
The Hygrothermal Performance of Exterior Wall Systems: Key Points of the Oak
Ridge National Laboratory NET Facilities Research Project
January 1, 2005 through March 30, 2006
Background: The US Department of Energy (DOE), through the Office of Energy Efficiency
and Renewable Energy's Building Technologies Program, and the EIFS Industry Members
Association (EIMA) jointly funded a 3 year (15 months completed) field research project
conducted by the Oak Ridge National Laboratory (ORNL) on moisture intrusion, drying potential
and energy performance of various configurations of exterior cladding systems (EIFS, brick,
stucco, concrete block and cementitious fiber board siding). In addition, the impact of
innovative EIFS features, specifically liquid applied moisture control membranes, smart vapor
retarder systems, and exterior cladding venting, on the performance of EI FS was evaluated.
The research to investigate the side-by-side hygric performances of each wall cladding system,
the field data and the hygrothermal model derived from it are particularly useful not only in
developing guidelines for the use of EIFS but also in demonstrating the superior moisture and
temperature control performance of EIFS as compared with other types of exterior claddings.
The study is continuing into a second year of field-testing, incorporating additional
configurations and wall cladding parameters, such as purposefully induced defects.
Study Goals: The primary goals of the study are:
• To validate the moisture and thermal performance of EIFS wall systems
• To quantify the performance of EIFS over other types of exterior claddings
• To develop and calibrate a hygrothermal (moisture and temperature) computer model
with the unique features of EIFS that will validate the computer model for all climatic
regions
Study Location: Charleston, SC and Oak Ridge National Laboratory, Oak Ridge, Tennessee
Study Approach: In keeping with the DOE's strategy of promoting awhole-building approach
to building design, operation and maintenance, the research project considered the building
envelope in its entirety, rather than studying isolated materials or component systems. The
research approach is summarized below:
• Characterize the moisture, and thermal performance properties of critical construction
materials and sub-systems used in exterior wall systems
• Confirm the predictions of computer model by comparing them to actual field results
• Conduct field testing on a variety of exterior wall systems to determine their thermal, air
leakage and moisture control performance in real world, average environmental
conditions, including some severe-environmental conditions, during the course of one
year
• Employ hygrothermal modeling to simulate field tested exterior wall systems to
determine how to improve critical cladding system elements, with the goal of optimizing
their performance
• Develop design methodology that will permit architects and engineers to optimize energy
efficiency while controlling air and moisture transport to prevent material deterioration
and potential fungal contamination of the indoor environment
Facility Design. To achieve these goals, a special building was designed and constructed near
Charleston, South Carolina. The 15 exterior cladding configurations to be evaluated were
integrated into one side of the building (southern exposure). In this way, all of the exterior
claddings would be exposed to similar weather conditions during the course of the study.
Building orientation and placement of the exterior wall test panels were determined after
considerable study of historical weather patterns, including the prevailing direction of
precipitation.
Exterior Cladding Panel Configurations. While other types of exterior claddings were
studied, the primary focus of this project was various EIFS configurations, including EIFS with
drainage systems.
Sensor Placement and Data Collection. Each of the wall panels contained a variety of
sensors that recorded a full, constant profile of temperature, heat flux, relative humidity, and
moisture content. These sensors collected data 24 hours a day, 7 days a week and transmitted
the data to the ORNL Building Thermal Envelope Systems & Materials Energy Division
Research facility in Oak Ridge, Tennessee for analysis. Data upon which the conclusions were
derived were collected during a period of 15 months, January 1, 2005 through March 30, 2006,
and included average monthly weather observations and both interior and exterior sensor
readings.
Results and Conclusions. The research data lead to the following findings and support the
following statements:
• The best performing wall system was the EIFS wall consisting of four inches of
expanded polystyrene insulation board without any interior stud insulation (no
fiberglass). This wall outperformed all other walls in terms of moisture while maintaining
superior thermal performance.
EIMA Research Project Page 2 Of 3 OaII If~e Negmml la~a[arY
• The brick clad wall systems tended to accumulate more moisture and retain moisture
longer than EIFS cladding.
• The cementitious fiberboard siding wall systems tended to accumulate more moisture
and retain moisture longer than the EIFS cladding.
• The wall panels with polyethylene vapor retarders have higher wood moisture content
and excessive sheathing relative humidity (80 percent and higher). The results from this
study clearly indicate that the use of a polyethylene vapor retarder is not a good
strategy. Instead, interior vapor retarders that are highly vapor permeable and do not
provide a resistance to moisture drying are recommended in hot and humid climates.
• EIFS walls may employ house wraps as exterior water-resistive barriers; however,
moisture movement and accumulation is higher in these wall systems when compared
with water-resistive barrier coatings used aswater-resistive barriers. EIFS with water-
resistive barrier coatings, used as water resistive barriers, performed significantly better
than other claddings that used building paper. Wall panels with water-resistive barrier
coatings outperformed spun-bonded polyolefin membranes.
• EIFS using grooved expanded polystyrene insulation board improves the performance of
the wall, since venting is enhanced.
• Insulation is more beneficial when placed towards the exterior.
• EIFS drainage assemblies, using vertical ribbons of adhesives, provide a drainage path
and air space that contributes positively towards the hygrothermal performance of the
walls.
• EIFS installed over glass mat faced, modified gypsum core sheathing that is attached to
steel studs performs slightly better for interior vapor control strategies that are open
(higher water vapor permeance) as compared with EIFS attached over wood sheathing
and wood studs.
The wall system demonstrating the worst hygric performance was the brick, followed by the
stucco clad systems (both 3-coat and 1-coat), and then the cementitious fiberboard cladding.
Please note that the brick used in this research project is not particularly liquid absorptive. It will
be informative to observed gap between the performance of brick and EIFS in subsequent
studies if brick that is more representative of typical products is used.
Additional Findings, Conclusions, and Insights. Evaluation of the first year's results is
continuing, as is the collection of the data, which is going into its second year. The first-year
results along with the results from the second year undoubtedly will yield additional findings,
conclusions, and insights. Interested persons are encouraged to check back with EIMA for
updates.
EIMA Research Project Page 3 of 3 OBII f~ ~~ 18hq'BtOry
"°- AIA/ARCHITECTURAL RECORD
'.,,~ CONTINUING EDUCATION Series
sta
Air/Moisture Barriers
for Moisture Control and Mold
Prevention in Wall Construction
Fluid applied air/moisture barriers are effective and economical menus 4f controlling moisture
in wall assemblies. Moisture control assists in preventing mold growth in wall assemblies. Fluid applied
air/moisture barriers also offer performance advantages over building wraps and traditional asphalt
impregnated felt or paper moisture barriers. They can be used in all types of wall construction over wood,
gypsum and cement based sheathings. They can also be used over prepared concrete and concrete masonry
units. They generally consist of three components (Figures Ia and Ib on page 2I D):
1. A trowel applied joint treatment for filling sheathing joints, spotting fasteners, and protection
of rough openings, corners and other changes of plane in sheathed wall construction.
2. A reinforcing mesh or tape used in conjunction with the joint treatment to reinforce sheathing
joints, corners, and changes of plane, and for repair of minor cracks in concrete or concrete
masonry wall construction.
3. A waterproof coating applied by trowel, spray, roller or brush to prepared sheathing, concrete
or concrete masonry wall surfaces.
When properly applied to sound supporting construction, these components function together as an air
barrier and seamless moisture barrier in the wall assembly. Some of the advantages of a fluid applied
air/moisture barrier include:
Effectively blocks air leakage Increases occupant comfort,
Reduces energy costs by reducing heating and cooling loads,
Reduces risk of condensation caused by air leaks through
the wall construction
Seamless moisture barrier No tears, holes, or lap joints that can compromise
- j
performance in servrce, Reduces risk of installation errors {{I
----- ._..-------- - --- -----
-- - - - --
Protects sheathi ng and rough 1
Minimizes risk of weather damage to sheathing and associated ~
openings from weather damage repair or replacement costs
during and after construction ~
.
_
I
-
-
------ - -
Simple installation procedures .__
--_.._...--°--~ ---
----------____..
°_-----__
--
No special tools or skills required, reduces labor costs
Durable Does not tear or lose its effectiveness with exposure to weather
during construction or while in service
Structural/fully adhered Rigid and stable under air pressure loads, does not tear
or blow off the wall with wind
Distinct color Facilitates job site inspection and quality control j
Water based Safe to use, easy clean-up, VOC: compliant ~^ ~
Provides opportunity for pressure Minimizes risk of rain water penetration through wall assembly i
equalized or pressure moderated
wall design
Doubles as air barrier and Efficient use of materials ~
moisture barrier in wall assembly ~
Advertising supplement provided by 5to Corp.
Use the learning objectives below to focus your
study as you read Fluid Applied Air/Moisture
Barriers #or Moisture Control and Moid
Prevention in Wall Construction. To earn
one AIAICES Learning Unit including one hour of
health safety welfare credit, answer the questions
on page 7, then follow the reporting instructions
on page 8 or go to the Continuing Education
section on »nvw.architectura2record.com and follow
the reporting instructions.
Learning Objectives
• Know the components of fluid applied
air/moisture barriers
Compare the advantages of fluid air/moisture
barriers with building wraps and other moisture
barriers
Identify design considerations when
incorporating fluid applied air/moisture barrier
systems into wall assemblies
~ "' AIA/ARCHITECTURAL RECORD
'.,,§ CONTINUING EDUCATION Series
"'°- AIA/ARCHITECTURAL RECORD
'-..:~ CONTINUING EDUCATION Series
Joint treatment and
reinfor
Figure la: Fluid Applied Air/Moisture Barrier applied to
sheathing by roller
of coating
Fluff A lie Air/ r in Wall Constructio
d pp d Moisture Barrie s for Moisture Control and Mold Prevention
In the last decade studies (CMHC, Commissioning and Monitoring the
Building Envelope for Air Leakage, Odom, David J. III, Preventing Indoor Air
Quality Problems in Educational Facilities: Guidelines for Hot, Humid
Climates) have shown air leakage to be a significant potential source of
condensation and moisture accumulation in building envelope assemblies.
By constructing an airtight building envelope the risk of moisture
problems-decay, corrosion, loss of insulation value, mold growth and IAQ
(Indoor Air Quality) problems-that can occur because of air leakage and
condensation are minimized. At the same time airtight construction is likely
to be less capable of drying than "air-porous" construction in the event of
water leakage or other unforeseen circumstances that cause water to enter
into a wall assembly. The designer then must strive to prevent rain water
penetration into the wall assembly, to construct an airtight building envelope
assembly of compatible air barrier materials, and to enhance the drying
potential of the wall assembly in his/her overall design strategy. When
incorporating fluid applied air/moisture barriers in wall assemblies, the
following considerations are important to effectively control condensation
and prevent moisture penetration:
Design Considerations
• Air permeability
Continuity with other air barrier materials
Structural integrity
Durability
Water penetration resistance
Water vapor permeability
Mechanical ventilation
Construction details and sequencing
Code compliance
Climate
Air Permeability
The layers of material that make up a wall assembly have different air
permeability. Figure 2 provides a comparison of typical materials used in wall
assemblies and heir air permeability v Tues.
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Figure 2: Air Permeability jL/(s•m2)J of Fluid Applied Air/tVloisture Barrier
and Common BuildingMateriats
Sources of Data: Canada Mortgage and Housing Corporation and Sto Corp.
Energy codes in the United States have begun to require air tightness of the
building envelope, but they are not specific about levels of air permeability for
air barrier materials. The generally accepted level based on National Building
Code of Canada requirements is 0.02 L/(s•m2) at 75 Pa pressure [0.004 cfm/ft2)
at 1.57 psf)]. While many common building materials like plywood and gypsum
wallboard meet this standard, a sheathed wall assembly will not perform well
as an air barrier unless the joints are treated with an air barrier material.
The sheathed wall assembly with treated joints then becomes an air barrier
sub-system of the total building envelope air barrier system. The total building
envelope air barrier system consists of all the interconnected air barrier
materials-for example, treated wall sheathing, roof membrane, foundation
waterproofing, windows, and doors, and the air barrier connection materials
between them.
Advertising supplement provided by 5to Corp.
Figure 16: Fluid applied air/moisture barrier applied to sheathing by spray application
"°~ AIA/ARCHITECTURAL RECORD
=,:~ CONTINUING EDUCATION Series
Air Barrier Continuity
Fluid Applied Air/Moisture Barriers for Moisture Control and Mold Prevention in Wall Construction
The overall design concept of air barriers in building construction is the
creation of a continuous airtight membrane around the building envelope.
Therefore air barrier materials in wall assemblies, to be effective, must be
continuous. Breaks in air barrier continuity cause air leaks. In cold climates
the breaks can allow significant amounts of warm moisture laden air to
escape from the interior environment and condense on a cold surface in the
wall assembly. Conversely, in hot humid climates, breaks in the air barrier
permit moisture laden air from the exterior environment to infiltrate the
building envelope and potentially condense on a cold surface in the wall
assembly. Any penetration through the wall assembly or termination of the
wall assembly must therefore be detailed to maintain the continuity of the
air barrier materials to effectively create an air barrier system. Without
continuity of the afr barrier materials in the wall assembly air barrier system
performance is less effective. The design/construction professional must take
material compatibility and construction sequencing into account when
designing an airtight assembly to ensure continuity. A number of connecting
air barrier materials exist that are compatible with fluid applied
air/moisture barriers to make transitions from one material to the next,
for example, rubberized asphalt membrane tapes to connect from wall
sheathing to foundation, or low expanding urethane foam sprays for use
between windows and rough openings.
Air Barrier Structural Integrity
Structural integrity of air barriers is important because wind loads are
transferred to the most airtight components in a wall assembly, the air barrier
materials, and in turn, are transferred to the structure. Negative and positive
wind loads stress air barrier materials. If the materials tear or displace with
loading they lose their effectiveness as air barriers. Some building wraps have
low air permeability, but they do not perform well as commonly installed, not
only because they have many seams that reduce their effectiveness against air
leakage, but they are non-structural. If the seams in building wraps are not
taped they do not perform well as air barrier materials. Because building
wraps are non-structural they are susceptible to displacement and tearing with
negative wind gusts in cavity wall construction. This compromises their
performance in service.
Fluid applied air/moisture barriers are fully adhered. Adhesion to sheathing
exceeds the strength of the sheathing. Tensile adhesion tests show that the
paper or glass mat facing fails in gypsum based sheathings, while unfaced
sheathings like plywood show adhesive failure at loads in excess of 344 kPa
(50 psi, could equate to more than a 2560 kmlhr [ 1600 mphJ wind speed).
The structural strength of the fluid applied air/moisture barrier in effect
equates to that of the sheathing. Deformation while in service is ]invited to
the deformation of the sheathing. This means no tears and no compromise in
performance caused by structural loading, provided the sheathing and
supporting frame are adequate to resist loads.
Air Barrier Durability
While capable of resisting wind loads without compromise in performance, air
barrier materials must also demonstrate durability in a number of other ways,
particularly if the air barrier is concealed and inaccessible For maintenance.
Durability criteria include:
• Resistance to puncture
• Resistance to pests-rodents, termites, carpenter ants, and other insects
Resistance to low but sustained negative pressures from building stack
effect and HVAC fan effect
Ability to withstand stress from thermal and moisture movement of
building materials, and stress from building creep
Resistance to W degradation (during the construction period)
Resistance to mold growth
Resistance to abrasion
Fluid applied air/moisture barriers generally do not provide a food source
for insects or other pests. By virtue of their excellent adhesion to sheathing and
prepared concrete or masonry substrates, they are resistant to puncture and
they resist loads imposed by stack effect and fan effect, as well as wind loads.
Their resistance to stresses imposed by Thermal and moisture movement, and
building creep, is mainly dependent on the ability of the joint treatment
material to span gaps in sheathing without cracking. This performance, in
turn, is dependent on the physical properties of the specific joint treatment
material. Similarly, the iIV resistance, resistance to mold growth, and abrasion
resistance are dependent on the physical properties of the joint treatment and
waterproof coating materials.
Water Penetration Resistance
The traditional moisture protection used in wall construction is asphalt
saturated felt or kraft waterproof building paper. The terms weather-resistive
barrier or moisture barrier are often used to describe these components in
wall construction. They are generally installed over sheathing by lapping them
shingle style and fastening with nails, screws or staples to the sheathing.
Their general purpose in walls is to protect against ingress of incidental water
into the building and to protect moisture sensitive components like gypsum
sheathing in the event of a breach in the outer wall covering, such as a crack
in stucco. Building wraps are often used in place of asphalt felt in wall
construction, often with the same perceived purpose. The water resistance,
air infiltration resistance, and vapor permeability characteristics of building
wraps vary widely, depending on the brand of wrap selected (See references,
PHRC Report No. 59). Seamless fluid applied moisture protection provides
a significant improvement over traditional moisture protection and building
wraps. In fact, they can be 10 times more resistant to water penetration than
building wraps and nearly 200 times more resistant to air leakage than asphalt felt
(refer to Figures 2 and 3).
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190 480 5-hour Water penetration
= 400 Resistance Requirement at
55 cm per SBCCI PST & ESI
Evaluation Guide 119
200
55 35.6 30.5 22.9
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Figure 3: Water penetration resistance of fluid applied air/moisture barrier
material compared to building wraps and building paper. Check page 7
for figure 3 notes.
Advertising supplement provided by Sto Corp.
"~~• AIA/ARCHITECTURAL RECORD
e.~ CONTINUING EDUCATION Series
Fluid Applied Air/Moisture Barriers for Moisture Control and Mold Prevention in Wali Construction
Water Vapor Permeability
A fluid applied air/moisture barrier may or may not be a vapor retarding
material. The generally accepted definition of a vapor retarding material is one
that has a water vapor permeance of 57.4 ng/(Pa•s•mZ) [ 1.0 perms] or less. In
table 1 the fluid applied air/moisture barrier components are not vapor
retarders. The joint treatment has a vapor permeance of 994 ng/(Pa•s•mZ) [ 17.3
perms] and the waterproof coating has a vapor permeance of 327 ng/{Pa•s•mZ)
[5.7 perms], about the same as Type 15 building felt.
Water Vapor Water Vapor
8utlding Material Permeance (Perms) Permeance ngl(Pa•s•m2)
4 mil Polyethylene' 0.08 4.60
6 mm (eta inch) Plywood' (ext glue) 0.7 40.2
101 mm (4 inch) Brick' 0.8 46.D
2D3 mm (6 inch) Concrete Block' 2.4 138
25 mm (1 inch) Expanded Polystyrene' S 287
Type 15 Building Felt' S.6 322
Fluid Applied Air Moisture 5.7 327
Barrier Water
roof Coatin
p
g
19 mm (3/a inch) Plaster on Metal Lath' 15 862
Fluid Applied Air Moisture 17.3 994
Barrier Joint Treatment
9.5 mm (3/a inch) Gypsum Wallboard' S0 2673
Table 1: Water Vapor Permeance of Fluid Applied Air/Moisture Barrier Materials
and Common Building Materials. Check page 7 for Table 2 notes.
The purpose of a vapor retarder in wall construction is to minimize water
vapor diffusion through the wall assembly and thus reduce the risk and the
amount of condensation on cold surfaces in the wall assembly. Whether or not
a vapor retarder should be placed in a wall assembly and where it should be
placed must be carefully evaluated in relation to climate, the physical
characteristics of other components of the wall assembly, and interior relative
humidity conditions. In cold climates the predominant water vapor diffusion
direction through most of the year is from the inside to the outside, as warm
humid air from the interior environment moves in the direction of cold dry
outside air. Conversely, in hot humid climates the predominant water vapor
diffusion direction through most of the year is from the warm humid outside
environment towards the cooler, dryer conditioned interior environment.
Based on these general conditions a vapor retarder is customarily placed on the
interior of wall construction in cold climates and on the exterior in hot humid
climates. A vapor retarder should not be placed on the interior in hot humid
climates, since it will potentially cause condensation by restricting vapor diffusion
to the interior. The use of interior vapor retarders has been shown to be a
contributing cause in many cases of moisture problems and IAQ problems in
buildings in hot humid climates. One tool that is available to assist in making
decisions about whether a vapor retarder is needed and where to place it in the wall
assembly is a water vapor transmission analysis that can be performed manually
(see ASHRAE Handbook-Fundamentals, chapters 21 and 22) or by computer
(Trechsel, Moisture Analysis and Condensation Control in Building Envelopes).
Mechanical Ventilation
A properly functioning air barrier system will limit the influence of air
infiltration and exfltration on the heating and cooling loads of the interior
environment. This can increase the efficiency of the HVAC system which
translates into energy cost savings. However the mechanical ventilation system
must still perform its basic functions of:
• Ventilation and exhaust
• Proper distribution of makeup air to interior spaces
• Dehumidification of air
• Filtration of outdoor air
Wind effects, stack effects, fan effects and space configuration and partitions
influence how the mechanical ventilation system must be designed to perform
adequately. ASHRAE handbooks provide guidance on mechanical ventilation,
and design and control of interior relative humidity conditions to control
microbial growth, to minimize condensation potential, and to provide occupant
comfort, in relation to air leakage.
Construction Details and Sequencing
"As much as 90 percent of all water intrusion problems occur within 1 percent
of the total building exterior surface area. The 1 percent of the structure's fa4ade
contains the terminations and transition detailing that all too frequently lead to
envelope failures:''
Construction detailing is a critical component for the success of any wall
assembly. The designer must create details that effectively:
Control rain water penetration that may occur via:
• Gravity flow-water that flows down and to the interior if surfaces are
sloped towards the interior, for example, an improperly sloped brick ledge
• Kirretic energy-rain water, for example, being blown directly into large
openings
• Capillary action-the tendency of water to travel through narrow openings
or cracks in materials toward dryer surfaces, for example, a crack in a
mortar joint
• Pressure differentials-the effects of wind pressure, stack effector
mechanical ventilation that create pressure differences across the building
envelope, and drive water through cracks or openings
Control condensation that may occur via:
• air leakage
• diffusion
The contractor must in turn coordinate and sequence work so that
details are properly constructed. Given that today's buildings are generally
"tighter" than they were fifty years ago, the importance of eliminating
water intrusion into wall assemblies increases substantially, since water in
walls may not readily dry. Some details are fundamental such as the proper
sloping of sills and ledges to the exterior, use of drip edges at soffit returns,
capillary breaks in construction joints, or lapping of the air/moisture
barrier over flashing at the base of a wall {Figure 4) to direct water to the
exterior. Other details are more complex, such as maintaining the
continuity of the air barrier at a window penetration (Figure 5) and
integrating the air/moisture barrier with sill flashing. Whatever the detail,
whether straightforward or complex in nature, the development and
execution of details is vital to the long term success of the wall assembly,
regardless of how well the air/moisture barrier system performs. An
important advantage of a fluid applied air/moisture barrier in the wall
assembly is that it can mitigate or eliminate one of the major forces that
cause water infiltration into walls: pressure difference. The fluid applied
air/moisture barrier, in combination with venting and compartmenting,
can effectively enable the pressure behind the cladding material to equalize
with the pressure outside, and prevent rain water penetration caused by
pressure differentials (pressure equalized rainscreen).
4 Advertising supplement provided by sta Corp.
"'~- AIA/ARCHITECTURAL RECORD
,,~ CONTINUING EDUCATION Series
Waterproof Coating
Splice strip of reinforcement,
joint treatment, and waterproof
coating instalted over flashing
Figure 4: Fluid applied air/moisture barrier lapped onto flashing at the base of
the wall to "splice" the two materials and shed water onto the flashing and to
the exterior.
Code Compliance
United States
Model building codes and state and municipal codes in the United States do
not address air barriers, moisture barriers and vapor retarders in a uniform
way. Energy codes in the United States, including the IECC (International
Energy Conservation Code), the State of Massachusetts Building Code, and
ASHRAE's 1999 energy conservation standard (ANSI/ASHRAE/IESNA
Standard 90.1-1999, Energy Standard for Buildings Except Low-Rise
Residential Buildings, an energy conservation standard which is required to
be adopted by state building energy codes under the Federal Energy
Conservation and Production Act} require air tightening of the building
envelope. Although codes in the United States do not always provide specific
limits for air leakage of air barrier materials, the generally accepted limit is
0.02 L/(s•m') at 75 Pa pressure [0.004 cfm/ft2) at 1.57 psf)] based on
National Building Code of Canada requirements.
Most model codes generally require the use of awater-resistive barrier in
wall construction and prescribe asphalt saturated felt (IBC Chapter 14,
paragraph 1404.2). They often require the use of vapor retarders in wall
construction (IBC Chapter 14, paragraph 1403.3) unless other means are
provided to avoid condensation.
Pluid applied airlmoisture barriers are proprietary materials and are not
listed in model codes. Provisions are made for non-traditional building
materials like building wraps and fluid applied air/moisture barriers as an
"alternate material, design or method of construction."' Approval by the
building official is based on his/her finding that "....the intent of the
provisions of the code [are met] ...and that it [the air/moisture barrier
material] is at least equivalent in quality, strength, effectiveness, fire
resistance, durability and safety to the materials or methods of construction
listed in the code:" In practice the building official cannot evaluate each and
every new material or method of construction, so model code evaluation
agencies do this for him/her and publish evaluation reports which describe
the use and limitations of alternate materials. Therefore it is always
important to verify compliance of a fluid applied air/moisture barrier material
with the code via an evaluation report.
Southern Building Code Congress Public Safety Testing and Evaluation
Advertising supplement provided by sto Corp.
;!
/'
' Fluid applied air/moisture barrier
~~ ~f
i,
•' Interior crir seat
l~ndow sill flashing
E
Air Seal
Figure 5: Integration of the fluid applied air/moisture barrier at the rough
opening with interior air seal and sill flashing beneath the window.
Services, Inc. publishes an Evaluation Guide on Floor, Wall, and Roof Systems
(Testing for Moisture Protection Barriers-SBCCI PST er ESI Evaluation Guide
119), which lists specific performance criteria for air and moisture barriers,
including fluid applied air/moisture barriers. Conformance with these
criteria is the basis for code recognition of fluid applied airlmoisture
barriers. ICBO ES (International Conference of Building Officials, Inc.)
is similarly in the process of developing a criteria for water-resistive coatings
that function as alternates to UBC (Uniform Building Code) prescribed
weather-resistive barriers.
Cannda
The National Building Code of Canada requires an air barrier system
encompassing the entire building envelope, a vapor barrier if condensation
is expected, and control of precipitation (Chapter 5, Environmental
Separation, Sections 5.4-5.6). Multiple standards are listed in the code that
identify performance requirements for building materials. New materials for
which a standard has not yet been written undergo technical evaluation by
CCMC (Canadian Construction Materials Centre}, who publishes evaluation
reports which verify compliance of a material or assembly with the intent of
the code. Some airlmoisture barrier materials have been shown to meet the
requirements for air leakage as a material component of an air barrier system
and are either listed or currently under evaluation by CCMC.
Typical Wall Assemblies with Fluid Applied Air/Moisture Barriers for
Climate Zones in North America
The model wall constructions illustrated below are examples of wall
constructions that incorporate a fluid applied air/moisture barrier in two
climate zones of North America. In each case the fluid applied air/moisture
barrier functions as an air barrier and moisture barrier material over the
sheathing that:
• Protects the sheathing from moisture damage during construction
• Minimizes air leakage into the wall cavity and to the interior
environment from warm humid outside air in hot humid climates
(and during summer months in cold climates)
• Protects the sheathing against incidental moisture that may occur
outboard of the sheathing but behind the cladding while in service
• Minimizes air leakage from the interior towards the exterior in cold climates
Advertising supplement provided by Sto Corp.
_ "'"~ AIA/ARCHITECTURAL RECORD
'..,~ t~NTINUING EDUCATION Series
Interior Paint
(Vapor Permeable) ..: ; .: -:
Gypsum
'allboard
Batt Insulation
(unfaced)
Figure 6a: Fluid Applied Air/Moisture Barrier in Hot Humiet Climate Zone
Fluid Applied Air/Moisture Barriers for Moisture Control and Mold Prevention in WaII Construction
attached with metal fasteners, and, to minimize penetration
with mechanical fasteners. The installation of the wood
siding over strapping creates a cavity to promote drying of
--~ Brick Ueneer the wood in the event it gets wet during construction or
while in service.
-I " (25 mm cavity) In cold climates the vapor retarder is essential (unless
Rigid XEPS Insulation mechanical controls are in place to adequately control
• (with Vertical Grooves interior relative humidity conditions in winter). The vapor
far Drainage) retarder minimizes water vapor diffusion to the exterior
Fluid Applied during winter months. However, it is essential to eliminate
Air/Moisure Barrier leaks, condensation, or any other source of moisture in the
frame wall cavity, given that the vapor retarder on the
Gypsum Sheathing interior and the fluid applied air/moisture barrier and
on Steel Stud insulation on the exterior create a very "tight" construction
with limited drying potential.
Note, in cold climates it is important to:
The fluid applied air/moisture barrier has a unique advantage as compared
to building wraps beneath non-contact siding such as brick veneer with a cavity
because it is in effect structural and does not tear and lose its effectiveness with
negative wind gusts during construction or while in service.
Note, in hot humid climates it is important to:
• Use a water vapor permeable interior wall covering to permit drying
to the interior and to prevent condensation immediately behind the interior
wall covering.
• Use unfaced batt insulation to permit water vapor diffusion and drying
to the interior
• Pressurize the interior space with conditioned (dehumidified) air so that
warm humid outside air is not drawn to the interior
• Use a low permeabce rigid insulation on the exterior to resist vapor
diffusion to the interior, especially if porous cladding like brick veneer is used
Note that the rigid EPS insulation (as opposed to XEPS insulation) is chosen
because it is vapor permeable. The vertical grooves in the insulation drain
incidental moisture. The insulation is adhesively attached to the fluid applied
air/moisture barrier to prevent thermal bridging that would occur if it was
Interior Paint
(Vapor Permeable
or Impermeable)
Gypsum
Vapor Retarder
Batt Insulation
Fluid Applied
Air/Moisture Barrier
Gypsum Sheathing
on Steel Studes
Figure 6h:. Fluid Applied AirlMoisture Barrier in Cold Climate Zone
I/2" (I3 mm) Air Space
• Insulate on the exterior, particularly when metal studs are used, to prevent:
• Telegraphnig (ghosting) of metal studs on the interior or exterior
wall surfaces
• Heat loss via conduction through the metal studs
• A dew point from occurring in the metal stud cavity and condensation
which can lead to corrosion
• Adjust the type and/or thickness of the rigid insulation to prevent a dew
point in the frame cavity and condensation on or within the wall
sheathing. As the size of the stud cavity increases and the thicluiess of batt
insulation increases the dew point moves further to the exterior with the
risk of the sheathing becoming a condensing surface.
• Provide a neutral or slightly negative indoor pressure to prevent exfiltration
of warm humid air into cold walls
Note that each of the above model wall constructions illustrates a design
strategy that incorporates a fluid applied air/moisture barrier, and other
design considerations for the effective control of moisture in the wall
assembly. As each building is different and has its own unique set of
materials, climate, and interior conditions to consider, these model wall
assemblies should be taken as a guide relative to any specific project.
Appropriate adjustments in materials, and their position in the assembly
Wood Siding over Strapping
(with vapor permeable paint)
Rigid EPS Isullation (with
Vertical Grooves for Drainage)
should be made. The overall design strategy must
include prevention and control of rain water
penetration, minimizing the risk of condensation
caused by water vapor diffusion or air leakage, and
maintaining proper mechanical controls of the
interior environment.
Fluid applied air/moisture barrier materials are
effective components in wall assemblies that control
moisture by minimizing air leakage and protecting
water-sensitive components from moisture. Their
material properties such as water vapor
permeability, UV resistance and mold resistance
must be taken into account. They are cost effective
alternatives for moisture control in wall assemblies
that have several performance advantages over
building wraps and traditional asphalt saturated felt
or paper moisture protection. ^
Advertising supplement provided by sto Corp.
°~-: AIA/ARCHITECTURAL RECORD
'-„~ CONTINUING EDUCATION Series
Fluid Applied Air/Moisture Barriers for Moisture Control and Mald Prevention in Wall Construction
KnoSV the components of fluid applied airlmoisture barriers
Compare the advantages of fluid air/moisture barriers with
building wraps and other moisture barriers
Identify design considerations when incorporating fluid applied
air/moisture barrier systems into wall assemblies
er to the learning objectives above. Complete the questions
~w. Go to the self report form on page 8. Follow the reporting
:ructions, answer the test questions and submit the form.
use the Continuing Education self report form on Record's
site-architecturalrecord.com-to receive one AIAICES Learning
it including one hour of health safety welfare credit.
estions
1. United States energy codes are ahvays specific about the levels of air
permeability for building materials.
a. True
b. False
2. Pluid applied airlmoisture barriers' excellent adhesion Co sheathing and
prepared concrete or masonry substrates makes them resistant against:
a. Wind loads
b. Insects or other pests
c. Mold growth
d. UV degradation
3. Seamless fluid applied moisture protection is nearly Times
more resistant to air leakage than asphalt saturated felt.
a. 100
b. 150
Q: 4. A fluid applied air/moisture barrier is also always a vapor retarding material.
A: a. True
b. False
Q: 5. In cold climates, a vapor retarder is customarily placed on which?
A: a. the interior side of the wall
b. the exterior side of the wall
Q: 6. "As much as 90 percent of all water intrusion problems occur within
percent of the total building exterior surface area:'
A: a. 1
b. 5
c. 10
Q: 7. Rain water blown directly into large openings is an example of
which mechanism of rain water penetration?
A: a. Gravity flow
b. Kinetic energy
c. Capillary action
d. Pressure differentials
Q: 8. One of the major forces that causes water infiltration into walls is:
A: a. Kinetic energy
b. Gravity flow
c. Pressure difference
Q: 9. Fluid applied airlmoisture barriers are proprietary materials and are
not listed in model codes.
A: a. True
b. False
Q: 10. In which climate should you use a low permeance rigid insulation on
the exterior to resist vapor diffusion to the interior?
A: a. Hot humid climates
b. Cold climates
Toole 1 Notes:
1. Dry Cup Method
2. Wet-Cup Method
3. Other Method
4. Note: this chart provided for information only. Direct comparisons of water vapor
permeance values may not always be applicable, as different methods of measuring
produce different results. Materials may also have varying water vapor permeability
with changes in relative humidity.
S. Sources of Data: ASHRAE Handbook Fundamentals and Sto Gorp.
Figure 3 Notes:
1. Source of Data: independent testing by Cerny & Ivey Engineers
2. Fluid applied air/moisture barrier materiel did not leak, but met limit of testing fixture.
3. Materials tested in accordance with AATCC-127 (American Association of TextIle
Chemists and Colorists Test Method 127-Water Resistance: Hydrostatic Pressure Test
[modified]). A column of water 55 cm (21. fi inches) tall is placed over the moisture
barrier material and sealed to the surface. The moisture barrier material spans a 3
mm (1/8 inch) evide joint in supporting sheathing. Building wraps and building
paper are not penetrated with fasteners. Time to water penetration is then measured.
For the materials that met the 5 hour criteria, the height of the water column was
increased to determine the limits of the material.
References
American Architectural Manufacturers Association, Installation Masters Training Manual.
Schaumburg: AAMA, 2000.
American Architectural Manufacturers Association, Window Selection Guide. Palatine:
AAMA, 1995.
American Association of Textffe Chemists and Colorists, AATCC-127 Water Resistance
Hydrostatic Pressure Test. AATCC, 1995.
American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc, 1993
ASHRAE Handbook-Fundamentals, (I-P Edition), Atlanta: ASHRAE, 1993.
Anastasi, Leonard, "Air Barrier Systems for the Life or Your Building," The Construction
Specifier, (March, 2002), 30-35.
Ants, Wagdy "Insulation Strategies for Exterior Walls," The Construction Specifier,
(August, 2002), 40-45.
Canada Mortgage and Housing Corporation, Commissioning and Monitoring the Building
Envelope for Air Leakage, (Report No. 33127!02), Ottawa: CIvIHC,1993.
Canada Mortgage and Housing Corporation, Rainscreen, Ottawa: CMHC.
Cerny & Ivey Engineers, Inc., Water Penetration Resistance Testing Sto Gold Guard
(Engineering Report No. 20409), Atlanta: Cerny & Ivey Engineers, Inc., 2001.
International Code Council, Codes Forum(September/October), Falls Church: ICC, 2002.
Construction Specifications Canada and Alberta Building Envelope Council, CSC
TF,K~AID Digest Air Barriers, Toronto: CSC & ABEC, 1490.
Foundatimt of the Wall and Ceiling Industries, Mold: Cause, Effect and Response, Itasca:
FWCI, 2002.
International Code Council, Inc., International Building Code. Falls Church: ICC, Inc., 2000.
International Conference of Building Officials,. Uniform Building Code, (Vol. 3), Whittier:
ICBO, 1997.
Kubal, Michael, T, Waterproofing the Building Envelope, New York: McGraw-Hill, Inc., 1993.
Lstiburek, Joseph. Builder's Guide. Minneapolis: Energy and Environmental Building
Assvciation,2001.
National Research Council of Canada, National Building Code. Ottawa: NRCC, 7995.
Southern Building Code Congress International Product Safety Testing Evaluation
Services, Inc., Evaluation Guide on Floor, Wall, and Roof Systems (Testing for
Moisture Protection Barriers). Birmingham: SBCCI PST & ESI, 1995.
Odom, David J. III, Preventing Indoor Air Quality Problems in Educatiotral Facilities:
Guidelines for Hot, Humid Climates, Orlando, 1997.
Odom, David J. III, "Solving Indoor Air Quality Problems in Hot, Humid Climates;'
Building Standards (September-October, 1994), Whittier: International
Conference of Building Officials, 1994.
Pennsylvania Housing Research Center, The Use of Housewrap in ~Nalls: Installation,
Performance and Implications, (PHRC Research Series Report No. 59),
University Park: PHRC, 1998.
Trechsel, Heinz R„ Moisture Analysis and Condensation Control in Building Envelopes,
{ASTM MNI,40), 4lrest Conshohocken: ASTM, 2001.
Footnotes
1. The Use of Housewrap in WaIIs: Installation, PerFormance and Implications, PHRC
Research Series Report No. 59 (University Park, 1998), p. 41.
2. International Code Council, Inc., International Building Code (Falls
Church, 2000), p. 3.
3. Ibid.
Advertising supplement provided by Sto Corp.
""'~ AIA/ARCHITECTURAL R E C 0 R D Fluid Applied Air/Moisture Barriers for Moisture Control aed Mold Prevention in Wall Coestruetion
-.,,~ CONTINUING EDUCATION Series
11YSPONV
Program title: Fluid Applied Air/Moisture Barriers for Moisture Control and Mold Prevention in Wall Construction,
Arch~tectura! Record (11{02, page 209)
AIA/CES Credit: This article will earn you one AIA/CES LU hour of health safety welfare credit. (Valid for credit through July 2004)
Directions: Select one answer for each question in the exam and completely circle appropriate letter. A minimum score of 70% is
required to earn credit.
1. a b c d 6. a b c d
2. a b c d 7. a b c d
3. a b c d 8. a b c d
4. a b c d 9. a b c d
5. a b c d 10. a b c d
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For Customer Service, call: 877-876-8093.
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Reprinted with permission from Architectural Record, November 2002
Phone: (8oo)zzl-z397
,r.
Fax: (404)346-3119
market) n gsu pport~stocorp.com
_„_ _ ___ _ wwwstocorp.com
Advertising supplement provided by Sto Corp.
sl°o
Sustainable Design
W~tn StoTherm~ NExT
;, Insulated Wall Claddings
For more than 50 years, Sto has been committed to the concept of
environmental, economic and social sustainability.Our motto, °Building with
conscience," focuses on this commitment.
Several design decisions contribute to the overall energy
efficiency of a building. One significant factor is the airtight-
ness of the building envelope. An airtight, well insulated
building enclosure can save energy and create superior
indoor climate control and comfort.
Superior Insulation and Higher R-Value
Comparable Nominal R-Values of Wall Assemblies
28
LL 34
~ 20
rs
j 16
F-
m 13
a
m 8
K a
2632
i&
16.7s
1:7z
6.97
5.69 .`1:~:
!-~'a:
Concrete Siding Cavity EIFS
4" thickness
3" thickness
2" thickness
1"thickness
StoTherm NExT insulated wall claddings provide a blanket of
insulation around the exterior of the building, eliminating the
thermal breaks characteristic of between-the-stud insulation.
A broad range of R-Values may be achieved by using EPS in
varying thickness from 3/a" to 4" (19-102 mm).
Protection Against Air Infiltration and Heat Loss
StoTherm NExT systems
with proper details can
reduce exterior air and
moisture infiltration at
foundation and wall
joints, wall outlets and
vents by as much as 55%
compared to typical
construction.
StoTherm NExT systems
greatly reduce heat loss
through the walls, which
can account for up to
40% of the heat loss in
non-EIFS construction.
h ~I..
A .t.
A continuous layer of insulation placed outbound of the studs
minimizes thermal bridging, significantly increasing the effective
R-Value of the watt assembly.
Sto Building with conscience.
Sto knows the impact buildings can have on the environment. That's why it`s our mission to
maintain the value of both new and existing buildings for their owners, investors and users by
providing product systems and services that improve a building's energy efficiency, durability
and aesthetic appeal.
• Reduced Structural Requirements -A StoTherm®Insulated Wall Cladding adds ve
compared to other wall claddings, which means less material is required when calcul<
foundation footings, particularly as the height of the structure increases.
• Building Reuse -StoTherm NExT systems can be applied to properly cleaned surface
cement block and even painted surfaces, extending the life of existing building stock
alleviating problems like poor insulation and air leakage.
Research by the
Department of
Energy's Oak Ridge
National Laboratory
shows EIFS walls
to be the "best
performing wall
systems" providing
"superior moisture
and temperature
control. "* ~ ,• . ~:: .
"Source: The Hydrothermal Performance of Exterior
Wall Systems: Key Points of the Oak Ridge National
laboratory NET Facilities Research Project
StoTherm® NExT Ensures [
"Sustainability" isn`t just about energy efficiem:
It starts with durable design, followed by sounc;
longevity. Without durability as the cornerstone
sustainable building features are lost. StoTherm
durability by protecting the sheathing from satl
vapor pass through -thus helping the wall dry,
the wall assembly.
Materials and Resources
Locally Sourced Materials -Locally extracted rr
manufactured close to the job location, reduce
wrought by the transportation of materials.
• StoTherm NExT components are manufactw
US and Canada. A majority of the raw mate)
components are extracted locally to these m
Contact your local distributor for more information.
Please visit us at www.stocorp.com or call us toll-free at 800-221-2397.
ATTENTION
Sto Building with conscience.
Reducing the quantity of new materials needed for a building reduces environmental irr~
extraction and disposal of construction waste.
•
Sto Corp. ~ WaterproofinglAir Barrier
•
Sto Building with conscience.
stb
StoGuardTM
Superior Spray-On
Building Wrap
Protect First. Make it Last?""
The StoGuard'" assembly.
What is the StoGuardT"" assembly?
StoGuard offers several application options for joints, rough openings and sheathing boards depending
on preference and cladding type.
The StoGuardT'" assembly is
applied in two steps:
Step One -Initial air barrier component
StoGuard joint and rough opening treatment choices:
• StoGuard Mesh and Sto Gold FII
• StoGuard Fabric with Sto Gold Coat or Sto EmeraldCoat
• StoGuard Tape (peel & stick)
Step Two -Extended air barrier protection and
waterproofing component
StoGuard sheathing board treatment choices:
• Sto Gold Coat is specially formulated for use under EIFS and
other claddings
• Sto EmeraldCoat is specially formulated for use under stucco
and other claddings
Both Sto Gold Coat and Sto EmeraldCoat can be applied by
spray, roller or brush to wall sheathing and prepared concrete
or concrete masonry wall construction. Both coatings pass
ASTM D-1970 for nail sealability.
Note: The ASTM test standard is for a nail over a wood substrate.
StoGuard Mesh and Sto Gold FII
a ~~
~ ~,dy ~ v t
`J~ S~""~C~~,45' ~ ~n
3~ ~~,,'u °3o)P ~•
^3~4 ~ ~ ~~,~iy~ '~~'Y f
ev 3::
~~ .~
StoGuard Fabric with Sto Gold Coat
or Sto EmeraldCoat
StoGuardT"" is durable!
Since waterproofing and air barrier materials are hidden
behind cladding and consequently inaccessible for
maintenance or repair, make sure to choose a durable,
structural barrier. StoGuard is a proven long-wearing
waterproofing air barrier.
StoGuard has undergone rigorous testing by independent test
agencies to demonstrate compliance with the International
Code Council -Evaluation Service and the Canadian
Construction Materials Centre (GCMG) criteria to confirm its
durability. StoGuard has been proven to be an extremely
durable waterproofing and air barrier material with
exceptional drainage performance.
How is StoGuardT`" installed?
The StoGuard assembly of products is easier to install than
sheet wraps and does not require highly skilled labor. Sto Gold
Coat and Sto EmeraldCoat can be applied with an airless
sprayer, roller or brush for the same smooth continuous
protection. The gold or green product color makes application
inconsistencies easy to identify. Unlike some solvent-based
materials, StoGuard has low VOCs and is not toxic. No
additional breathing apparatus or special handling is necessary.
~;, r~~
Sto Gold Coat is specially formulated for
use under EIFS and other claddings
Sto EmeraldCoat is specially formulated for
use under stucco and other claddings
Cl
•
.~
•
•
Superior waterproofing.
Unlike conventional sheet wraps that tear apart at the seams and leak
through the staple holes, the StoGuard assembly of products is seamless
and tear proof.
Moisture protection in wall construction
The function of moisture barriers in walls is to protect against the transfer of incidental water into the
building. Additionally, they shield moisture sensitive components, such as wood or gypsum-based
sheathings, in the event of a breach in the outer wall covering, such as a crack in stucco.
the conventional choice for moisture protection has been asphalt saturated felt or paper. In addition to
tearing and mis-lapping during construction, felt or paper might suffer significant performance break
down with exposure to weather conditions. StoGuard can be left uncovered for up to six months (Sto
Gold Coat) or two months (Sto EmeraldCoat) with minimal degrading.
StoGuardT"": superior waterproofing
StoGuard has the added ability to allow water vapor to pass through yet keep damaging liquid water
from penetrating and saturating the sheathing. By applying StoGuard as your waterproofing treatment
you can have the peace of mind that your walls have minimized risk of damage from water intrusion
during or after construction.
StoGuard resists water penetration for up to 75 minutes when subjected to water spray equivalent to
eight inches (203 mm) of rainfall per hour driven by an approximate 50 mice-per-hour (80 km/hJ wind.
Note: The product was tested in accordance with ASTM E-337 at simultaneous pressure of 6.24 psf (300 PaJ
and waterspray of 5 gal/ftz/hr (3.41lmlyminJ.
Vapor permeable.
Unlike some sheet membranes that do not allow water
vapor to diffuse through, the StoGuard assembly is water
vapor permeable.
By allowing for water vapor diffusion,
while limiting air infiltration, StoGuardT"'
is "breathable."
Asa "breathable" waterproof air barrier, StoGuard permits water vapor to
diffuse through it. This is important for the drying of the wall, should water
accumulate in materials during construction or incidental water leakage
occur after construction.
Some sheet membranes do not allow vapor diffusion, which can result in a
damp or saturated building assembly.
Large liquid water drop
on tap of opening
How can a material be both waterproof
and vapor permeable?
water vapor consists of very small individual water molecules in a
gas form. Water vapor molecules will easily flow through pores
and openings in a material. More, or larger, openings result in
more vapor that flows through. Materials that permit the passage
of water vapor are termed vapor permeable.
~~
x
z
a :F
C
.
.r~,~.
J
~'
Small water vapor molecules
passing through opening
Liquid water is cooled water molecules held tightly together via
cohesion. The tight cohesive force creates surface tension that
draws water into larger round drops. This surface tension allows
water to cling to other objects. Surface tension will cause liquid
water to bridge the small holes that water vapor can pass through.
~~ - - __~~
StoGuard has been tested in accordance with AATCC-127 (modified),
Water Resistance: Hydrostafic Pressure Test, and resists water
penevation for months. Ordinary housewraps and building papers,
depending on brand or type, measure water resistance in hours, and
in some cases, allow water penetration within the first few minutes
of e~rosure.
Critical Detail Checklist
for Wall Assemblies
r
1. Provide flashing 2. Provide diverter 3. Protect rough
at decks flashingg at openings
roofJsidewall
terminations
4. Provide sill
flashing
beneath
windows and
doors
7. Seal around
wall
penetrations
>-,
10. Provide saddle
flashing at
lowerlhigher
wal I
intersections
5. Provide head 6. Seal around
flashing above window and
windows and door
doors penetrations
n
C)
I I
8. Provide joints 9. Provide coping
at required over parapets
locations and
seal where
necessary
Also see Moisture Control Principles
for Design of Wall Assemblies in
StoGuard`":Air Barrier and Moisture
CorrtrolHandbook.
Sto Corp.
3800 Camp Creek Parkway
Building 1400, Suite 120
Atlanta, GA 30331
Tel: 404-346-3666
Toll Free: 1-800-221-2397
Fax: 404-346-3119 a
www.stocorp.com ~~-Sf~.
5105G 09!07 VEN 5609
Sto Building with conscience.
For Exterior Walls, Sto Beats All
• Superior air leakage resistance and moisture protection;
impervious to liquid water; protects sheathing and rough
opening during construction; protects sheathing against
incidental leaks and air leakage after construction.
• Struc
clarity
loos adhesive bond
Hof; cannot be torn or stretched
ral adhesive attachment to Shea ing, not
ible to wind pressure, lifting or tying. To qualify
it barrier requires structural staklity; StoGuard on
ng provides this.
a; protects exposed sheathing for up to six months
11d Coat). Waterproof; does not deteriorate with
re to water.
install. Spray application, no large sheets or rolls to
.Easily installed by one worker or a team, resulting in
d labor costs.
install; non-flammable, IowVOCs
r green color makes inconsistencies easy to identify
11 toolbox to support you...
•
ar technical support staffed with 20+ year
fiction veterans and supplemented with 24-hour
FAQS and Ask A Wizard.
Brilliantly colored cutaway details provide an in-depth
t reference allowing you to review instructions for
and precision.
ses: ~ ''
ATTENTION
Sto products are intended for use by qualified professional contractors, not consumers, as a component of a
larger construction assembly as specified by a qualified design professional, general contractor or builder. They
should be installed in accordance with those specifications and Sto's instructions. Sto Corp. disclaims all, and
assumes no, liability far on-site inspections, for its products applied improperly, or by unqualified persons or
entities, or as part of an improperly designed or constructed building, for the nonperformance of adjacent
building components or assemblies, or for other construction activities beyond Sto's control. Improper use of
Sto products or use as part of an improperly designed or constructed larger assembly or building may result in
serious damage to this product, and to [he structure of the building or its components. STO CORP. DISCLAIMS
ALL WARRANTIES EXPRESS OR IMPLIED EXCEPT FOR EXPLICIT LIMITED WRITTEN WARRANTIES
ISSUED TO AND ACCEPTED BY BUILDING OWNERS IN ACCORDANCE WITH STO'S WARRANTY
PROGRAMS WHICH ARE SUBJECT TO CHANGE FROM TIME TO TIME. For the fullest, most current
information on proper application, clean-up, mixing and other specifications and warranties, cautions and
disclaimers, please refer to the Sto Corp. website, www.stomrp.com.
•
High performance air barrier.
Before the StoGuard assembly, conventional sheet wrap products left
you hanging in the breeze. Use StoGuard for a superior air barrier with
seamless protection.
Air barriers in wall construction
The purpose of an air barrier in walls is to minimize air intrusion and leakage through the wall
construction.
The benefits of an air barrier are:
• Reduced risk of condensation caused by air leaks through the wall construction
Improved thermal efficiency of the wall construction
Decreased energy costs
Increased occupant comfort
• Provides opportunity for pressure equalized or pressure moderated wall system design, thus minimizing
the risk of rain water penetration through wall construction
Materials like asphalt saturated felts and some housewraps have low air permeability but do not perform
well as air barriers. This is not only because they have many seams that reduce their effectiveness, but
they are non-structural.
StoGuardT"": a high performance air barrier
StoGuard is continuous, structural (when applied to sheathing) and durable
Because StoGuard is permanently adhered to sheathing it becomes a part of overall physical structure.
There is no tearing or gapping between StoGuard and the sheathing, only smooth uninterrupted coverage.
This structural characteristic allows StoGuard to outperform sheet building wraps.
Sheet building wraps, which are attached with nails or staples, may have gaps that allow air infiltration
and leakage. They can also tear away from the fasteners or dislodge with wind gusts.
According to the Pennsylvania Housing Research Center "...house wraps do very little or nothing to
improve the overall air tightness of a wall system"
*Source: Pennsylvania Housing Research Center survey "The Use of Nousewrap in Walls: Installation, Performance
and Implications." 1999
Air permeability of StoGuardT""
The generally accepted air permeability level based on Canadian code requirements is 0.02 L!(s.mZ) [0.004
cfmlftz]. Based on independent testing StoGuard exceeds this criterion by a factor of more than 10.
What about air leakage and mold?
In the last decade, studies have shown air leakage to be a significant potential source of condensation
and moisture accumulation in building envelope assemblies. By constructing an airtight building envelope
the risk of moisture problems -decay, corrosion, loss of insulation value, mold growth and Indoor Air
Quality (IAQ) problems -that can occur because of air leakage and condensation are minimized.
StoGuardT'" is energy efficient!
According to US Department of Energy statistics "up to 40% of the energy consumed to heat or coal a
building is due to air leakage into and out of the building:' Using StoGuard helps prevent air leakage and
thus reduces energy costs,
A study of commercial buildings by the National Institute of Standards and Technology (NISn confirmed
that air barriers promote energy savings ranging from 30-40% for heating climates and 10-15% for
cooling climates.
Not only is StoGuard an air barrier, which can help with indoor air quality and energy savings, it is also
water-based with IowVOCs. Make sure your choice of air barrier is also good for the environment.
Comparison of Potential
Moisture contributed by Air
Leakage versus Vapor Diffusion
Extrapolation of data from: Preventing Indoor
Air Quaiity Problems in Educational FacifrUes:
Guidelines for Not, Humid Climates, by CH1MHill
in cooperation with Disney Development Company.
Air leakage versus vapor
diffusion.
While both air leakage and water vapor diffusion
deliver moisture to the assembly, recent studies
have shown air infiltration and exfiltration to be
a significant potential source of moisture
accumulation in walls and/or high relative
humidity levels in interior spaces.
Water vapor diffusion on the other hand has been
shown to be a much less significant potential
source of moisture than it once was thought to be.
The diagram above illustrates this difference.
When moving air contains water vapor, large
quantities of moisture can transport through
relatively small openings. Any tears, holes,
penetrations will increase this level of humidity
in a building.
Conventional sheet wrap
over period of One Year
What is StoGuardTM?
StoGuard is an efficient assembly
of products which combine to create
a waterproof air barrier in wall
construction. By protecting sheathing
first, this seamless spray-on building
wrap provides superior protection
against moisture intrusion and air
leakage.
During construction, StoGuard is
resistant to liquid water and protects
sheathing and rough openings. After
construction, StoGuard protects
against incidental water leaks and
air leakage.
~f/e imagine
the architectural
achievements
of the future...
And if the
future spaces
we build can
elevate the
qua;ity of life;
ir` they can inspire,
our mission
will ,have been
accom,olished.
Sto Corp.
3800 Cainp Creek Varkm~ay
Hulldina 1400, Soite Ru
Ntlanta, 6A 30331
iel: 404-34E-366fi
Tcll rcee: I-800-22 b239r
So"=
Fax: s04-346 3 i 1? 900
wwwstocorp.com
sioao a~a3 vw ~.5os
Sto is the innovative world leader
ir, daddirlg, coating and restoration
systems. Sto invented Exterior
Insulation and Finish Systems -
introducing E7FS to Europe in 7963.
Headquartered in Atlanta, Georgia,
Sto Corp., which is ISO 9001 certified,
continues to lead the North American
industry in innovation; providing the
highest quality products and services
to enhance our customers' projects.
Our industry leading Insulated Wall
Claddings, Stucco, Coatings and
Concrete Restoration products are
manufactured in three plants located
strategically across North America to
serve our more than 2G0 distributor-
ships in the U. S. and Canada.
We continue to revolutionize the
.industry with StoMachine Technology -
a faster more economic waV to apply
EIFS; Sto Studio, consultative design
and cobr services and the Sto Institute,
which trains building professionals in
proper techniques to ensure lasting
results.
Application Technology...Design_.
Education, and the highest quality
products make Sto the innovative
world leader in cladding, coating
and restoration systems.