HomeMy WebLinkAbout 17030109 MiscellaneousStep 4. EXCAVATION
Correct excavation of the pool is very important. A hole that is too small can mean hours of picking and shoveling by hand. A
hole that is too large will require extra recommended backfill material, which if not dealt with properly, can result in settling or
bulging of the pool.
The excavation should be dug very close to the pool size with a minimum disturbance to the unexcavated soil which will support
the pool. The clearance is approximately 6" on the sides and 6" on the ends (see Figure 2).
Figure 2 - Pool Shell Depth Dimensions
33'
62't2't2'}2'}2't 2' t 2F2-tj-
V} 2'} 2'-2-[-25'-4"
T5'-" ' SI-I I
3-203'" 3V-5" 5.pWe� 3-I I 5,_I 4_94:I
26'
of slope(s): 4.04'
The depth of the excavation is determined with the use of a transit leo�lF The bottom of the excavation is over
dug approximately 4". This size pool will require approximately 35 to 40 yards o or 1/2" clean gravel for backfill (more
may be required if the excavation is significantly over -dug). /o
The'excavation should be 16' by 33', with a total depth of approximately 3'-I 1" (shallow end) to approximately 5'-9" (deep
end) from the desired elevation of the pool. It can be helpful to give yourself extra room the first 6" in width and 12" in length
of the hole, to get past the coping, and allow space for the skimmer and bottom suction fittings (if any). Also, keep in mind that
the wall of our pools are tapered, usually I" in for every 12" in depth. A place for the skimmer must also be dug in the side of
the excavation wall. The skimmer cutout should be 2' by 2' and 3' deep. See Figure 1 for placement. Pools with tanning ledges
require the tanning 1¢dfe area excavated to the depth stated in Fig. I plus 4" for bedding material.
Never use excavated material as fill or backfill in the hole; the material will settle. We suggest sand or %:" clean gravel
compacted thoroughly (a plate tamper is needed for the pool base). The fill material used for the pool base must also be used to
backfill around the sides of the pool shell. In the case of significant over excavation on the sides of the pool or in seasonal high
water or poor drainage areas, you may want to mix 10% Portland cement with the backfill for stabilization.
Latham requires that a permanent sump pipe (see Figure 3) be in-
stalled on all pools. A gravity fed "daylight drain" is an acceptable
alternative to a permanent sump pipe installation. The purpose of
the sump pipe installation (or daylight drain) is to provide a means
of checking for groundwater around the pool and allow for dewa-
tering the site prior to any work on the pool that requires lowering
the water level within the pool shell, thus minimizing potentially
high hydrostatic pressure. Latham recommends the installation of
a permanent sump pump in areas with a high water table and/or
significant ground water. Latham suggests digging an 18" x 8' x
18" trench across the deep end of the excavation. Six inches of 1/2"
clean gravel should be placed in the bottom of the trench. A section
of 3" perforated PVC pipe is placed on the rock base and connected
to a vertical stand of 8" PVC pipe running to the surface of the ex-
cavation. Cover the new sump line with landscaping fabric. The 8"
PVC riser pipe should be trimmed with a skimmer ring and lid for
SKIMMER LID
AND RING
Figure 3 -
Sump Pipe Installation
SAND OR Ire WASHED GRAVEL
FIBERGLASS
POOL KNELL
SAND M In' WASNED GRAVEL
72
V.S.
Ur WASHED GRAVEL
S• PERFORATED PIPE
W PIPE