Excavation machinery and the actual fiberglass pool must get their way into the construction site. The pool shell can be moved by a crane, but heavy machinery must have an optimal route to the site and back without much obstruction.
Swimming pools and patios are commonly built on leveled and flat ground. Therefore, excessive variations in grade ought to be resolved before the hole excavation starts.
In most cases, to dig the hole, excavation equipment is required. It also can be used to load the hauling trucks with excavated material. Skid-Steer is definitely a big plus to help with grading and ground leveling. If using a crane to handle the pool, it is recommended to use four 20 feet straps or a spreader bar. If a track excavator is used for excavation and site preparation, it also can handle the pool. However, the excavator must be of an adequate size to carry the pool shell.
Pool delivery must be coordinated with the hole excavation completion and preparation for an install.
Before beginning any excavation or site preparation, check with local authorities for the underground utilities.
Overhead Power Lines
The power lines might obstruct the pool handling process from the delivery truck to the place of installation. Therefore, proper arrangements and planning are required before the pool delivery.
The high water table will require hole dewatering while excavating and constructing a hydro pressure relief system.
To protect a new inground pool, groundwaters should always be diverted away from the pool. Otherwise, it may result in damage to the pool’s exterior that is not covered under warranty.
Pool Equipment Location
Most likely, your township will require to approve the location of your pool utility before issuing a construction permit. Ideally, pool equipment must be located close to the pool, not further than 20 feet. The distance can be extended, but different pool circulation equipment must be installed to handle the water flow properly.
Most states and local municipalities require a licensed electrician to do the electrical hookup. Sometimes, if homeowners want to do their own electrical work, the township will allow doing so. In most cases, pool equipment is installed near the house to reduce the cost of electrical tranches and wiring.
Exposure to Sunlight
When planning a pool placement, consider the way the sun goes through the yard. It is always a good idea to have a pool covered with sunlight all day.
When preparing for excavation, make sure that the pool measurements are at hand. Most manufacturers show pool dimensions as to the outside line of the pool beam and not to the waterline. A Latham fiberglass pool’s coping (pool beam) is approximately 4″ to 6″ on all sides. Therefore, there is generally a difference of 8″ to 12″ between the length and width dimensions. For example, a pool shows a 16′ x 40′ dimension, but the actual waterline dimension is 15′ x 39′. For construction permits, the waterline dimension is the measurement required.
Instruction: Start by laying out the rectangular frame by adding 3 feet to the lengths and 3 feet to the width of the pool. Measure the center point of the rectangle and make sure the lines that go through the center lines are at 90 degrees. Put a stake or rebar pin in the ground for each measured point around the pool’s perimeter and connect each rebar pin with a construction string. Indicate skimmer location with a 2’x2′ box outside of the pool layout, and spraypaint the contour of the string with a solid line. If there spa or tanning pool, make sure to mark the location. Before digging, remove the string and pins.
The first and foremost rule is to always remember that water must run away from the pool.
Instruction: Inspect all four corners of the pool layout with transit or sight level to discover the highest corner. That corner will be used detrimental in calculating the elevation of the pool. Ideally, the final pool elevation should be 4 to 6 inches above the highest point of the final grade.
Proper excavation of the pool is essential. If you overdig the hole, it would require extra backfill material and can result in settling or bulging the pool shell. The excavation should be done very close to the pool size with a minimum disturbance to the virgin soil to support the pool. The margin is approximately 6″ on every side. Most fiberglass pool walls are tapered, usually 1″ in for every 12″ in depth. Allow extra space for skimmer and bottom drain, if any. The skimmer cutout space should be 2′ by 2′ and 3′ deep. The excavation depth is determined with the use of a transit level and grade pole. The bottom of the excavated hole should be over dug, approximately 4″ for a pool pad. Also, pools with tanning ledges require the tanning ledge area excavated adequately to the depth for bedding/pad material.
Suggested backfill materials are sand or ½” clean gravel. After the pool base is filled with material, it must be compacted with a plate tamper. If significant over-excavation on the sides of the pool, or if the site is located in seasonal high water or poor drainage areas, mix 10% Portland cement with the backfill for stabilization.
Dewatering system: Latham requires a permanent sump pipe installed on all pools, or also a gravity-fed “daylight drain” is an acceptable alternative to a permanent sump pipe installation. Suppose the water in the pool must be lowered for any reason. In that case, it will allow dewatering from underneath and around the pool, also minimizing potentially high hydrostatic pressure to the pool walls.
Instruction: Dig 18″ x 18″ x 8′ trench across the deep-end of the excavation. Place six inches of 1/2″ clean gravel to the bottom of the trench. Place a section of 3″ perforated PVC pipe on the gravel base. Place vertically 8″ PVC pipe from the bottom of the deep-end to the top of the excavation surface. Connect perforated PVC pipe to the vertical stand, cover the new sump line with landscaping fabric, and cover perforated PVC pipe with 1/2″ to 1″ clean gravel to the bottom grade of the excavation. Trim vertical 8″ PVC riser pipe with skimmer ring and lid for aesthetics and safety.
Note: Never use excavated material as fill or backfill because it will settle.
The bottom of the excavated hole is now ready for a pool pad, approximately 4″ of the compacted base material. Proper pool pad preparation is essential for a leveling process and will eliminate settling and stress cracks.
Instruction: Install 2″ x 4″ master screed rails for the length of excavation, using wood or metal stakes. Diagonal measurement must be exact to ensure the bottom is square. Adjust the master screed rail(s) to the appropriate height using a transit level. Install the remaining screed rails parallel to the master screed rails using the offset dimensions, ensuring they are perfectly level to the Master screed rail(s). Spread a layer of fill material approximately 4″ deep evenly over the bottom of the excavation and rake it flat to the top of the screed rails. If the pad’s height is greater than 4″, use a plate tamper for compaction. Next, screed the pad, filling any low spots as you go. Then, remove the screed rails and fill the voids with fill material, careful not disturb the fill.
SETTING THE POOL
The most recommended method of handling the pool shell is using a crane or boom truck. Another recommendation is to lift all pools over 12′ wide with a spreader bar and 20′ lifting straps.
Instruction: Set the pool into a prepared hole and check for level. Walk over the bottom of the pool to detect any voids in the pad. As necessary, lift and reset the pool as many times as needed to achieve a good leveling. A good leveling is accomplished by raking the pad’s surface and walking around on the inside of the pool, detecting low spots. It is normal to feel a slight void under the pool’s center, but walking in the pool should cause the floor to rest on the pad, and the pool shell will conform to the base material under the weight of the water. The leveling norm must be within 1/2″ of level with preinstalled tile, or 1″ of the level if a tile is to be installed later during the installation. Any adjustments to the pool’s elevation must be made before water is added. At that time, the pool can be separated from the lifting equipment.
WATER AND BACKFILL
Water can be filled to the bottom of the first step on most pool shells without backfill material added against the shell wall. Must keep checking the pool to ensure that it is still leveled. If the pool shell does not remain level, the water should be removed entirely and the bedding material added or removed as necessary to achieve needed results.
Instruction: With backfill material placed around the pool shell, ensure that any voids at the wall-floor and step-floor are tightly packed with fill material. Once the pool shell is “locked in,” the fill/backfill process can continue. The radiuses of the pool must be adequately compacted. Poorly packed radiuses can result in hairline cracks and/or structural cracks due to deflection. Be sure to backfill slowly and thoroughly. The process of the backfill must be gradual and should work in conjunction with the water fill. The backfill and water should always be +/- 6″ of each other. Steps and swim-outs tend to droop as water weight pushes the pool shell down and to the sides, so slight adjustments may be needed with the levering device. Be sure not to raise more than intended.
Note: If the backfill is too rapid, it can bulge walls of the pool inward or outward if too much water precedes the backfill. If bulging does occur during the installation, the only remedy is to dig that area out and proceed correctly. However, slight bulging has only a visual effect while not affecting the structure of the pool.
A swimming pool circulation concept is relatively simple and can be described as follows. The pump creates a circulation by drawing pool water through the skimmer and main drains and pushing it through the filter back to the pool via the returns. More advanced filtering systems may include deck and therapy jets, air blowers, sanitizers, pool cleaners, etc.
Instruction: Ideally, pool equipment must be installed slightly above the pool’s elevation. However, if the equipment is placed below the water level, check or shut-off valves must be installed to prevent a flow back.
Instruction: The backfill should be removed from the top 8 inches, about 10-12 inches around the pool perimeter. For a rebar installation, drill half-inch holes into the lip of the pool every 3 feet. Place two-foot lengths of 3/8″ rebar in each hole and bent at 90-degree angles. Minimum of 4″ thick of concrete should be poured at least 3′ around the pool’s perimeter and must be worked into the area under the shell’s beam. To minimize air voids, ¾” holes may be drilled every 36″ to aid bleeding air. For a standard cantilevered deck, particular forms must be placed on the inside perimeter of the pool. These forms are attached to the pool beam using double-sided tape, screws, and wire tires. The cantilevered deck is installed the same day as a bond beam as a part of one monolithic pour. A concrete patio should be poured up to approximately ¼” of the top of the pool coping for pavers.
Note: The deck should have a gradual fall of ¼” per 12 inches of the horizontal deck to allow any surface water to be drained away from the pool.