HomeMy WebLinkAbout04 43 00 Stone Masonry.docSECTION 04 43 00 - STONE MASONRY
GENERAL
SUMMARY
Section includes the following applications of stone masonry:
Anchored to unit masonry backup.
Anchored to wood framing and sheathing.
Products
installed, but not furnished, in this Section include:
Steel lintels and shelf angles for stone masonry specified in Division 05 Section "Metal Fabrications."
Related Requirements:
1. Section
04 20 00 “Unit Masonry.”
SUBMITTALS
Product Data: For each type of product indicated.
For stone varieties proposed for use on Project, include test data indicating compliance with physical
properties specified or required by referenced ASTM standards.
Include stone accessories, and other manufactured products indicated.
Shop Drawings: Show fabrication and installation
details, including dimensions and profiles of stone units.
Show locations and details of joints.
Include details of mortar joints, sealant joints, and mortar joints pointed with sealant.
Show
locations and details of anchors and backup structure.
For installed products indicated to comply with design loads, include structural analysis data signed and sealed by the qualified
professional engineer responsible for their preparation.
Samples for Initial Selection: For colored mortar and other items involving color selection.
Samples for Verification:
For each
stone type indicated. Include at least three samples in each set for each type of stone, exhibiting extremes of the full range of color and other visual characteristics expected in
completed Work. Samples will establish the standard by which stone provided will be judged.
a. Limestone: Approved sample to be used as a general guide to final building appearance
not less than 12 inches square.
For each color of mortar required. Label Samples to indicate types and amounts of pigments used.
List of Materials Used in Constructing Mockups: List
generic product names together with manufacturers, manufacturers' product names, sources of supply, and other information as
required to identify materials used. Include mix proportions for mortar and source of aggregates.
Submittal is for information only. Neither receipt of list nor approval of mockups
constitutes approval of deviations from the Contract Documents unless such deviations are specifically brought to the attention of Architect and approved in writing.
Samples for Verification:
For each type and color of joint sealant required.
Welding certificates.
Qualification Data: For qualified Installer, fabricator, professional engineer, and testing agency.
Material
Test Reports: From a qualified independent testing agency, as follows:
Stone Test Reports: For each stone variety proposed for use on Project, provide test data indicating compliance
with required physical properties. Base reports on testing done within previous five years.
For metal components, indicate chemical and physical properties of metal.
Sealant Compatibility
and Adhesion Test Report: From sealant manufacturer complying with requirements in /division 07 Section “Joint Sealants” and indicating that sealants will not stain or damage stone.
Include interpretation of test results and recommendations for primers and substrate preparation needed for adhesion.
Preconstruction Sealant Field Test Report: From Installer, complying
with requirements in /division 07 Section “Joint Sealants”
Cold-Weather Procedures: Detailed description of methods, materials, and equipment to be used to comply with cold-weather
requirements.
QUALITY ASSURANCE
Installer Qualifications: A qualified installer who employs experienced stonemasons and stone fitters.
Refer also to Specification Section 01 40 00 “Quality
Requirements.”
Source Limitations for Stone: Obtain each variety of stone, regardless of finish, from one quarry, whether specified in this Section or in another Section of the Specifications,
with resources to provide materials of consistent quality in appearance and physical properties.
Source Limitations for Mortar Materials: Obtain mortar ingredients of a uniform quality,
including color for exposed masonry, from single manufacturer for each cementitious component and from single source or producer for each aggregate.
Source Limitations for Other Materials:
Obtain each type pf stone accessory and other material from a single manufacturer for each product.
Preconstruction Sealant Compatibility and Adhesion Testing: Submit ti joint-sealant
manufacturers, for compatibility and adhesion testing according to sealant manufacturer’s standard testing methods and Division 07 Section “Joint Sealant,” samples of materials that
will contact or affect joint sealants.
Preconstruction Field Testing of Sealants: Before installing joint sealants, field test their adhesion to joint substrates per requirements specified
in Division 07 Section “Joint Sealants.”
Preconstruction Stone Testing: Engage a qualified independent testing agency to perform preconstruction testing indicated below.
Retesting of materials that fail to meet specified requirements
proposed for incorporation into the Work.
Furnish test specimens that are representative of materials proposed for incorporation into the Work.
Flexural Strength Tests: For stone variety,
thickness, orientation of cut, and finish, proposed for use on Project, tested according to ASTM C 99 for modulus of rupture, in both wet and dry conditions. See ILI Handbook for performance
tables.
Mockups: Build mockups, if requested in writing by Architect, to demonstrate aesthetic effects and set quality standards for materials and execution.
Build mockups for each
type of stone masonry in sizes approximately 60 inches long by 48 inches high by full thickness, including face and backup wythes and accessories.
Include stone coping at top of mockup.
Include
mortar with non-staining pigment.
Show typical components, attachments to building structure, and methods of installation.
Include a sealant-filled joint at least 16 inches long in
mockup.
Include through-wall flashing installed for a 24-inch length in corner of mockup approximately 16 inches down from top of mockup; with a 12-inch length of flashing left exposed
to view (omit stone masonry above half of flashing).
Include metal studs, sheathing, veneer anchors, flashing, in exterior masonry-veneer wall mockup.
Protect accepted mockups from the
elements with weather-resistant membrane.
Approval of mockups is for color, and texture; relationship of mortar and sealant colors to stone colors; tooling of joints; and aesthetic qualities
of workmanship.
Approval of mockups is also for other material and construction qualities Architect specifically approves in writing.
Approval of mockups does not constitute approval
of deviations from the Contract Documents contained in mockups unless Architect specifically approves such deviations in writing.
Approved mockups may become part of the completed Work
if undisturbed at time of Substantial Completion.
Pre-installation Conference: Conduct conference at Project site.
DELIVERY, STORAGE, AND HANDLING
Store and handle stone and related
materials to prevent deterioration or damage due to moisture, temperature changes, contaminants, corrosion, breaking, chipping, and other causes.
Lift stone with wide-belt slings; do
not use wire rope or ropes that might cause staining. Move stone, if required, using dollies with cushioned wood supports.
Store stone, if required, on wood skids or pallets with non-staining,
waterproof covers. Arrange to distribute weight evenly and to prevent damage to stone. Ventilate under covers to prevent condensation.
Mark stone units, on surface that will be concealed
after installation, with designations used on shop Drawings to identify individual stone units. Orient markings on vertical panels so that they are right side up when units are installed.
Deliver sealants to Project site in original unopened containers labeled with manufacturer’s name, product name and designation, color, expiration period, pot life, curing time, and
mixing instructions for multi-component materials.
Store cementitious materials on elevated platforms, under cover, and in a dry location. Do not use cementitious materials that have
become damp.
Store aggregates where grading and other required characteristics can be maintained and contamination avoided.
Deliver pre-blended, dry mortar mix in moisture-resistant
containers designed for lifting and emptying into dispensing silo. Store pre-blended, dry mortar mix in delivery containers on elevated platforms, under cover, and in a dry location
or in a metal dispensing silo with weatherproof cover.
Store masonry accessories, including metal items, to prevent corrosion and accumulation of dirt and oil.
PROJECT CONDITIONS
Protection
of Stone Masonry: During construction, cover tops of walls, projections, and sills with waterproof sheeting at end of each day's work. Cover partially completed stone masonry when
construction is not in progress.
Extend cover a minimum of 24 inches down both sides and hold cover securely in place.
Stain Prevention: Immediately remove mortar and soil to prevent
them from staining the face of stone masonry.
Protect base of walls from rain-splashed mud and mortar splatter by coverings spread on the ground and over the wall surface.
Protect sills,
ledges, and projections from mortar droppings.
Protect surfaces of window and door frames, as well as similar products with painted and integral finishes, from mortar droppings.
Protect
top course of all limestone when there is clay masonry above. Washdown of the clay brick above must be isolated from stone masonry below.
Turn scaffold boards near the wall on edge
at end of each day to prevent rain from splashing mortar and dirt on completed stone masonry.
Cold-Weather Requirements: Do not use frozen materials or materials mixed or coated with
ice or frost. Do not build on frozen substrates. Remove and replace stone masonry damaged by frost or freezing conditions. Comply with cold-weather construction requirements contained
in ACI 530.1/ASCE 6/TMS 602.
Cold-Weather Construction: When ambient temperature is within limits indicated, use the following procedures:
At 40 deg F and below, produce mortar temperatures
between 40 and 120 deg F by heating mixing water, sand, or both. Do not heat water to above 160 deg F.
At 32 deg F and below, maintain temperature of mortar on boards above freezing.
Heat stone and substrates so they are above 32 deg F at time of installation.
At 25 to 20 deg F, heat both sides of walls under construction. Use windbreaks or enclosures when wind velocity
exceeds 15 mph.
At 20 deg F and below, provide enclosure and auxiliary heat to maintain air temperature above 32 deg F within enclosure.
Cold-Weather Protection: When mean daily temperature is within limits indicated, provide the following protection for 48 hours after construction.
40 to 25 deg F. Cover dimension stone
cladding with weather-resistant membrane.
25 to 20 deg F. Cover dimension stone cladding with weather-resistant, insulating blankets or provide enclosure and heat to maintain air temperature
above 32 deg F within enclosure. Use windbreaks or enclosures when wind velocity exceeds 15 mph.
20 deg F and below. Provide enclosure and heat to maintain air temperature above 32
deg F within enclosure.
Cold-Weather Cleaning: Use liquid cleaning methods only when air temperature is 40 deg F and above and will remain so until masonry has dried, but not less
than 7 days after completing cleaning.
Hot-Weather Requirements: Comply with hot-weather construction requirements contained in ACI 530.1/ASCE 6/TMS 602.
Environmental Limitations for
Sealants: Do not install sealants when ambient and substrate temperatures are outside limits permitted by sealant manufacturer or below 40 deg F or when joint substrates are wet.
COORDINATION
Advise
installers of other work about specific requirements for placement of reinforcement, veneer anchors, flashing, and similar items to be built into stone masonry. Coordinate installation
of inserts that are to be embedded in concrete or masonry, flashing reglets, and similar items to be used by stone installer for anchoring, supporting, and flashing of installed stone.
Furnish setting drawings, templates, and directions for installing such items and deliver to Project site for installation.
Time delivery and installation of stone to avoid extended
on-site storage and to coordinate with work adjacent to stone.
PRODUCTS
STONE
Varieties and Sources: Subject to compliance with requirements, provide stone of varieties and from sources
indicated.
LIMESTONE
Limestone: Comply with ASTM C 568.
Products: Indiana oolitic limestone quarried in Lawrence, Monroe, or Owen Counties, Indiana.
Classification: II Medium-Density.
Description
: Oolitic limestone.
Dolomitic limestone shall not be allowed as a substitution for oolitic limestone.
Indiana Oolitic Limestone Grade and Color: Standard, buff; according to grade and color classification established by ILI.
Cut stone from one block or contiguous, matched blocks in which
natural markings occur.
Thickness: Not less than 3 inches unless otherwise indicated.
Finish, Matching Standard ILI Finish: Smooth finish, Split faced and Rock faced.
MORTAR MATERIALS
Portland
Cement: ASTM C 150, Type I or II, except Type III may be used for cold-weather construction. Provide natural color or white cement as required to produce mortar color indicated.
Low-Alkali
Cement: Not more than 0.60 percent total alkali when tested according to ASTM C 114.
Hydrated Lime: ASTM C 207, Type S.
Portland Cement-Lime Mix: Packaged blend of portland cement
complying with ASTM C 150, Type I or III, and hydrated lime complying with ASTM C 207.
Products: Subject to compliance with requirements, provide one of the following:
Essroc, Italcementi
Group; Saylor's Plus.
Holcim (US) Inc.; Rainbow Mortamix Custom Color Cement/Lime.
Lafarge North America; Eaglebond.
Lehigh Cement Company; Lehigh Custom Color Portland/Lime Cement.
Mortar
Cement: ASTM C 1329.
Products: Subject to compliance with requirements, provide the following:
Lafarge North America; Lafarge Mortar Cement or Magnolia Superbond Mortar Cement.
Masonry
Cement: ASTM C 91.
Products: Subject to compliance with requirements, provide one of the following:
Essroc, Italcementi Group; Brixment or Velvet.
Holcim (US) Inc.; Mortamix Masonry
Cement.
Lafarge North America; Magnolia Masonry Cement, Trinity Super White Masonry Type S, Trinity White Masonry Type N.
Lehigh Cement Company; Lehigh Masonry Cement, Lehigh White Masonry
Cement.
Mortar Pigments: Natural and synthetic iron oxides and chromium oxides, compounded for use in mortar mixes. Use only pigments with a record of satisfactory performance in stone
masonry mortar.
Products: Subject to compliance with requirements, provide one of the following:
Davis Colors; True Tone Mortar Colors.
Lanxess Corporation; Bayferrox Iron Oxide Pigments.
Solomon
Colors; SGS Mortar Colors.
Aggregate: ASTM C 144 and as follows:
For pointing mortar, use aggregate graded with 100 percent passing No. 16 sieve.
White Aggregates: Natural white sand or ground white stone.
Colored Aggregates: Natural-colored sand or ground marble, granite, or other sound stone; of color necessary to produce
required mortar color.
Match Architect's sample.
Water: Potable.
VENEER ANCHORS
Materials:
Stainless-Steel Wire: ASTM A 580, Type 304.
Stainless-Steel Sheet: ASTM A 240, Type 304.
Size:
Sufficient to extend at least halfway, but not less than 1-1/2 inches, through stone masonry and with at least 5/8-inch cover on outside face.
Wire Veneer Anchors: Wire ties formed
from W1.7 or 0.148-inch- diameter, stainless-steel wire.
Adjustable, Screw-Attached Veneer Anchors: Units consisting of a wire tie section and a metal anchor section that allow vertical
adjustment but resist tension and compression forces perpendicular to plane of wall, for attachment over sheathing to wood or metal studs, and as follows:
Products: Subject to compliance
with requirements, provide one of the following:
Dur-O-Wal, a Dayton Superior Company; D/A 213.
Heckmann Building Products Inc.; 315-D with 316.
Hohmann & Barnard, Inc.; DW-10 or DW-10HS.
Wire-Bond;
RJ-711.
Structural Performance Characteristics: Capable of withstanding a 100-lbf load in both tension and compression without deforming or developing play in excess of 0.05 inch.
Fabricate
sheet metal anchor sections and other sheet metal parts from 0.067-inch- thick, steel sheet, galvanized after fabrication.
Polymer-Coated, Steel Tapping Screws for Concrete Masonry:
Self-tapping screws with specially designed threads for tapping and wedging into masonry, with hex washer head and neoprene washer, 3/16-inch diameter by 1-1/2-inch length, and with
organic polymer coating with salt-spray resistance to red rust of more than 800 hours per ASTM B 117.
Products: Subject to compliance with requirements, provide one of the following:
ITW-Buildex;
Tapcon.
Powers Fasteners; Tapper.
STONE TRIM ANCHORS
Stone Trim Anchors:
1. 11 GA. strap anchors fabricated with tabs designed to engage kerfs or holes in stone trim units
and holes for fasteners or post-installed anchor bolts for fastening to substrates or framing as indicated.
2. Manufacturers: Subject to compliance with requirements, provide
products by one of the following:
Halfen Anchoring Systems; Meadow Burke.
Heckmann Building Products Inc.
Hohmann & Barnard, Inc.
Materials: Fabricate anchors from stainless steel, ASTM A 240, Type 304. Fabricate dowels from stainless steel, ASTM A 276, Type 304.
Fasteners for Stone Trim
Anchors: Annealed stainless-steel bolts, nuts, and washers; ASTM F 593 for bolts and ASTM F 594 for nuts, Alloy Group 1.
Post-installed Anchor Bolts for Fastening Stone Trim Anchors:
Chemical anchors torque-controlled expansion anchors or undercut anchors made from stainless-steel components complying with ASTM F 593 and ASTM F 594, Alloy Group 1 or 2 for bolts
and nuts; ASTM A 666 or ASTM A 276, Type 304 or 316, for anchors.
EMBEDDED FLASHING MATERIALS
Metal Flashing: Provide metal flashing, where flashing is exposed or partly exposed and
where indicated, complying with SMACNA's "Architectural Sheet Metal Manual and Division 07 Section "Sheet Metal Flashing and Trim" and as follows:
Stainless Steel: ASTM A 240, Type
304, 0.016 inch thick.
Metal Drip Edges: Fabricate from sheet metal indicated above. Extend at least 3 inches into wall and 1/2 inch out from wall, with outer edge bent down 30 degrees.
Metal
Flashing Terminations: Fabricate from stainless steel. Extend at least 3 inches into wall and out to exterior face of wall. At exterior face of wall, bend metal back on itself for
3/4 inch and down into joint 3/8 inch to form a stop for retaining sealant backer rod.
Flexible Flashing: For flashing not exposed to the exterior, use one of the following unless otherwise
indicated:
Copper: ASTM B 370, Temper H00 or H01, cold-rolled copper sheet, 10-oz. /sq. ft. weight or 0.0135 inch thick for fully concealed flashing; 16-oz. /sq. ft. weight or 0.0216
inch thick elsewhere.
2. Copper-Laminated Flashing: Manufacturer's standard laminated flashing consisting of 5- oz. /sq. ft. copper sheet bonded with asphalt between 2 layers of glass-fiber
cloth. Use only where flashing is fully concealed in masonry.
Products: Subject to compliance with requirements, provide one of the following:
Advanced Building Products Inc.; Copper
Fabric Flashing.
AFCO Products, Inc.; Copper Fabric.
York Manufacturing, Inc.; York Copper Fabric Flashing.
Solder and Sealants for Sheet Metal Flashings: As specified in Division 07
Section "Sheet Metal Flashing and Trim."
Adhesives, Primers, and Seam Tapes for Flexible Flashings: Flashing manufacturer's standard products or products recommended by flashing manufacturer
for bonding flashing sheets to each other and to substrates.
STONE TRIM ANCHORS
Stone Trim Anchors: Units fabricated with tabs or dowels designed to engage kerfs or holes in stone trim
units and holes for fasteners or post-installed anchor bolts for fastening to substrates or framing as indicated.
Materials: Fabricate anchors from stainless steel, ASTM A 240 or ASTM A 666, Type 304. Fabricate dowels from stainless steel, ASTM A 276, Type 304.
MISCELLANEOUS MASONRY ACCESSORIES
Compressible
Filler: Pre-molded filler strips complying with ASTM D 1056, Grade 2A1; compressible up to 35 percent; of width and thickness indicated; formulated from neoprene urethane or PVC.
Cementitious
Damp-proofing: Cementitious formulations that are recommended by ILI and that are non-staining to stone, compatible with joint sealants, and non-corrosive to veneer anchors and attachments.
Bond-Bre
aker Strips: Asphalt-saturated, organic roofing felt complying with ASTM D 226, Type 1 (No.15 asphalt felt).
Weep Hole/Vent Products: Use one of the following unless otherwise indicated:
Mesh
Weep Holes/Vents: Polypropylene cellular vents of polyester mesh head joint cell vent system, 3/8 inch x 2 1/2 inches x 3 3/8 inches, in color selected from manufacturer's standard
to match surrounding mortar.
Products: Subject to compliance with requirements:
CavClear/Archovations, Inc.; CavClear Weep Vents.
Mortar Net USA, Ltd.; Mortar Net Weep Vents.
Advanced
Building Products, Inc.; Mortar Maze weep vent.
No.85 Cell Vent, Heckmann Building Products.
Alternative Flashing-Weep Products: At Contractor's option, a copper fabric flashing and
drainage system may be used in lieu of separate embedded flashing and weep holes. Acceptable systems that may be incorporated into the Work include the following:
Products:
York Manufacturing,
Inc.; 5 oz. Flash-Vent (Red Label).
Cavity Drainage Material: Free-draining mesh, made from polymer strands that will not degrade within the wall cavity.
Provide one of the following
configurations:
Nylon polymer geo-matrix mesh: 0.80 inches thick by 13 inches high, in 50 foot rolls (Mortar Break).
Polypropylene mesh 1 inch by 10 inches high, in 5 foot panel lengths
(Mortar Net).
Products:
Advanced Building Products Inc.; Mortar Break.
Mortar Net USA, Ltd.; Mortar Net.
MORTAR MIXES
General: Do not use admixtures, including pigments, air-entraining
agents, accelerators, retarders, water-repellent agents, antifreeze compounds, or other admixtures, unless otherwise indicated.
Do not use calcium chloride.
Limit cementitious materials
in mortar to portland cement, mortar cement, and lime.
Mixing Pointing Mortar: Thoroughly mix cementitious and aggregate materials together before adding water. Then mix again, adding only enough water to produce a damp, unworkable mix
that will retain its form when pressed into a ball. Maintain mortar in this dampened condition for one to two hours. Add remaining water in small portions until mortar reaches desired
consistency. Use mortar within 30 minutes of final mixing; do not re-temper or use partially hardened material.
Mortar for Stone Masonry: Comply with ASTM C 270, Proportion Specification.
Mortar
for Setting Stone: Type N.
Mortar for Pointing Stone: Type N.
FABRICATION
Fabricate stone to comply with sizes, shapes, and tolerances recommended by applicable stone association or,
if none, by stone source, for faces, edges, beds, and backs.
For limestone, comply with recommendations in ILI's "Indiana Limestone Handbook."
Cut and select stone to produce pieces
of thickness, size, and shape indicated, including details on Drawings. Dress joints (bed and vertical) straight and at right angle to face unless otherwise indicated.
Cut and drill
sinkages and holes in stone for anchors and supports.
Carefully inspect stone at quarry or fabrication plant for compliance with requirements for appearance, material, and fabrication.
Replace defective units before shipment.
Clean sawed backs of stone to remove rust stains and iron particles.
Gage backs of stones for adhered veneer if more than 81 sq. in. in area.
Thickness
of Stone: Provide thickness indicated, but not less than the following:
Thickness: 4 inches plus or minus 1/4 inch. Thickness does not include projection of pitched faces.
Finish
exposed faces and edges of stone to comply with requirements indicated for finish and to match approved samples and mockups.
Finish: As indicated.
Finish for Sills: Smooth, unless otherwise
noted on drawings.
Finish for Lintels: Smooth, unless otherwise noted on drawings.
Finish for Copings: Smooth, unless otherwise noted on drawings.
Finish exposed ends of copings same
as front and back faces.
EXECUTION
EXAMINATION
Examine surfaces indicated to receive stone masonry veneer, with Installer present, for compliance with requirements for installation tolerances
and other conditions affecting performance.
Examine surfaces to receive dimension stone cladding and conditions under which dimension stone cladding will be installed, with Installer present, for compliance with requirements for
installation tolerances and other conditions affecting performance.
For the record, prepare written report, endorsed by Installer, listing conditions detrimental to performance of dimension
stone cladding.
Proceed with installation only after unsatisfactory conditions have been corrected.
Examine substrate to verify that dovetail slots, inserts, reinforcement, veneer anchors,
flashing, and other items installed in substrates and required for or extending into stone masonry are correctly installed.
Examine wall framing, sheathing, and weather-resistant sheathing
paper to verify that stud locations are suitable for spacing of veneer anchors and that installation will result in a weatherproof covering.
Proceed with installation only after unsatisfactory
conditions have been corrected.
PREPARATION
Accurately mark stud centerlines on face of weather-resistant sheathing paper before beginning stone installation.
Coat concrete and unit
masonry backup with asphalt damp-proofing.
Clean dirty or stained stone surfaces by removing soil, stains, and foreign materials before setting. Clean stone by thoroughly scrubbing
with fiber brushes and then drenching with clear water. Use only mild cleaning compounds that contain no caustic or harsh materials or abrasives.
SETTING OF STONE MASONRY, GENERAL
Perform
necessary field cutting and trimming as stone is set.
Sort stone before it is placed in wall to remove stone that does not comply with requirements relating to aesthetic effects, physical
properties, or fabrication or that is otherwise unsuitable for intended use.
Set stone to comply with requirements indicated on Drawings.
Maintain uniform joint widths except for variations
due to different stone sizes and where minor variations are required to maintain bond alignment if any. Lay walls with joints not less than 1/4 inch at narrowest points or more than
3/8 inch at widest points.
Provide sealant joints of widths and at locations indicated.
Keep sealant joints free of mortar and other rigid materials.
Sealing joints is specified in Division 07
Section "Joint Sealants."
Install metal expansion strips in sealant joints at locations indicated.
Install embedded flashing at shelf angles, lintels, ledges, other obstructions to downward flow of water in wall, and where indicated.
Coat limestone with cementitious damp-proofing
as follows:
Stone at Grade: Beds, joints, and back surfaces to at least 12 inches above finish-grade elevations.
Allow cementitious damp-proofing formulations to cure before setting
damp-proofed stone. Do not damage or remove damp-proofing in the course of handling and setting stone.
Place weep holes and vents in joints where moisture may accumulate, including
at base of cavity walls, above shelf angles, and at flashing.
Install vents in vertical head joints at the top of each continuous cavity at spacing indicated. Use mesh weep holes/vents
or open head joints to form vents.
CONSTRUCTION TOLERANCES
Variation from Plumb: For vertical lines and surfaces, do not exceed 1/4 inch in 10 feet, 3/8 inch in 20 feet, or 1/2 inch
in 40 feet or more. For external corners, expansion joints, control joints, and other conspicuous lines, do not exceed 1/4 inch in 20 feet or 1/2 inch in 40 feet or more.
Variation
from Level: For bed joints and lines of exposed lintels, sills, parapets, horizontal grooves, and other conspicuous lines, do not exceed 1/4 inch in 20 feet or 1/2 inch in 40 feet or
more.
Variation of Linear Building Line: For position shown in plan, do not exceed 1/2 inch in 20 feet or 3/4 inch in 40 feet or more.
Measure variation from level, plumb, and position
shown in plan as variation of the average plane of the face of each stone from level, plumb, or dimensioned plane.
Variation in Mortar-Joint Thickness: Do not vary from joint size range
indicated.
Variation in Plane between Adjacent Stones: Do not exceed one-half of tolerance specified for thickness of stone.
INSTALLATION OF ANCHORED STONE MASONRY
Anchor stone masonry
to unit masonry with wire anchors unless otherwise indicated.
Anchor stone masonry to stud framing with wire anchors unless otherwise indicated. Tie anchors to studs.
Embed veneer anchors
in mortar joints of stone masonry at least halfway, but not less than 1-1/2 inches, through stone masonry and with at least 5/8-inch cover on outside face.
Space anchors not more than 18 inches o.c. vertically and 32 inches o.c. horizontally, with not less than 1 anchor per 2.67 sq. ft. of wall area. Install additional anchors within 12
inches of openings, sealant joints, and perimeter at intervals not exceeding 12 inches.
Anchor stone trim with stone trim anchors where indicated. Install anchors by fastening to substrate
and inserting tabs and dowels into kerfs and holes in stone units. Provide compressible filler in ends of dowel holes and bottoms of kerfs to prevent end bearing of dowels and anchor
tabs on stone. Fill remainder of anchor holes and kerfs with mortar.
Set stone in full bed of mortar with full head joints unless otherwise indicated.
Provide 1-inch cavity between stone
masonry and backup construction unless otherwise indicated. Keep cavity free of mortar droppings and debris.
Place mortar spots in cavity at veneer anchors to maintain spacing.
Slope
beds toward cavity to minimize mortar protrusions into cavity.
Do not attempt to trowel or remove mortar fins protruding into cavity.
Rake out joints for pointing with mortar to depth
of 1/2 inch to 1 inch before setting mortar has hardened. Rake joints to uniform depths with square bottoms and clean sides.
POINTING
Prepare stone-joint surfaces for pointing with
mortar by removing dust and mortar particles. Where setting mortar was removed to depths greater than surrounding areas, apply pointing mortar in layers not more than 3/8 inch deep
until a uniform depth is formed.
Point stone joints by placing and compacting pointing mortar in layers not more than 3/8 inch deep. Compact each layer thoroughly and allow to become
thumbprint hard before applying next layer.
Tool joints, when pointing mortar is thumbprint hard, with a smooth jointing tool to produce the following joint profile:
Joint Profile:
Concave
ADJUSTING AND CLEANING
Remove and replace stone masonry that is broken, chipped, stained or otherwise damaged.
Stone may be repaired if method and results are approved by the
Architect.
Defective joints, stone masonry not matching approved sample or not complying with other requirements shall be removed and replaced.
In-Progress Cleaning: Clean stone masonry
as work progresses, only as required to remove dust or slush that impedes the erection process or application of joint sealants or pointing. Remove mortar fins and smears before tooling
joints.
Final Cleaning: After mortar is thoroughly set and cured, clean stone masonry as follows:
Remove large mortar particles by hand with wooden paddles and nonmetallic scrape hoes
or chisels.
Test cleaning method on mockup; leave one half of panel uncleaned for comparison purposes. Obtain Architect’s approval of sample cleaning before cleaning stone masonry.
Protect adjacent stone and non-masonry surfaces from contact with cleaner by covering them with liquid strippable masking agent, polyethylene film, or waterproof masking tape.
Wet wall
surfaces with water before applying cleaner; remove cleaner promptly by rising thoroughly with clear water.
Clean stone by bucket and brush hand-cleaning method described in BIA Technical
Note No.20 Revised II, using job-mixed detergent solution.
Clean limestone masonry to comply with recommendations in ILI’s “Indiana Limestone Handbook.
Do not use acid-type cleaning
agents, cleaning agents containing caustic compounds or abrasives, or other materials or methods that could damage stone.
END OF SECTION 04 43 00