Day one: Excavation
The first task is laying out the pool. To provide working space, all outer dimensions of the excavation should be made 609 mm (24 in.) larger than the actual pool size. The excavation is outlined by four re-rods, one at each corner. It is also important to square off the excavation layout.
Next, choose the elevation for the top of the coping (i.e. the top surface of the pool). This must be 76 to 101 mm (3 to 4 in.) above the highest ground elevation to prevent drainage problems. Conspicuously mark the highest elevation as the reference point. Always check the excavation depth from the reference point.
Given a steel-wall panel of 1067 mm (42 in.) and a coping height of approximately 51 mm (2 in.), the depth of the footing excavation will be 1118 mm (44 in.). This depth, measured from the top of the coping, will be maintained in the shallow end and on the 609-mm (24-in.) over dig around the pool perimeter. (The over dig can vary based on the size of the braces used with the pool.) Most excavators will work from the deep end to the shallow end in digging process. During the excavation, a transit should be used to ensure the proper depth is reached. The more level the shelf, the quicker and easier it will be to set the panels. Also be sure to leave the 609-mm over dig as a working ledge.
After the first part of the excavation is finished, lay out the exact pool size on the shelf. Then, on one side and one end of the over dig, mark the top edge of the hopper (i.e. deep end) slopes with string and cut the earth with a shovel using the string as a guideline. The excavated depth of the hopper should be 51 to 101 mm (2 to 4 in.) deeper than the finish dimensions. After checking to make sure the hopper is square, dig the plumbing trench at a depth of at least 457 mm (18 in.), reaching from the over dig to the equipment pad. This will make it easier to run the plumbing lines later.
Day two: Steel wall panel assembly
On day two, determine the placement for the skimmer and inlet fittings first. It is best to place the skimmer near the centre of one of the pool’s longer sides, in the direction the wind blows in the yard, to aid pool water circulation.
When ready to assemble the steel wall panels, set them in the over dig, leaning them against the side of the excavation in the order shown in the pool drawings. Starting at any corner, assemble two corner panels. Then, when two straight-wall sections are joined, use the braces attached at the top and bottom holes of the panel flanges and tighten the top and bottom bolts while checking for proper alignment. When the panels are flush, install and tighten all remaining bolts.
Proceed with the next panel joint, alternating in each direction from the first corner, using the corner to help stabilize the entire wall assembly. When using a step section, follow individual manufacturer instructions.
After all pool walls are assembled, make sure everything is perfectly square and parallel. Then, fit the pool to the deep end excavation as close as possible and use an alignment string, along the bottom length of the wall, to straighten the long wall first. Recheck the widths of the pool at the corners and then measure the assembly corner to corner. When the dimensions are equal, the pool is square. When the walls are straight, square, and parallel, drive re-bar into holes in the bottom flange of the steel wall panels along the perimeter to secure them. Also, drive triangular stakes through stake pocket holes in each brace, straightening the remaining walls along the way.
To ensure proper assembly, the pool must be levelled to the predetermined elevations. This can be accomplished by checking the level at each panel joint and each of the step’s four corners. Level with the transit, using shims under the pool walls as necessary. This is an extremely important stage of the installation; therefore, enough time should be devoted to this process to assure a perfectly level pool.
Once the pool is level and prior to pouring the bond beam, install the main drains. Check all codes to ensure compliance. Then, check the wall panels one final time for proper level and be sure to fill any voids to prevent concrete from running underneath the walls. When placing the concrete, do so gently as to avoid disturbing the straight wall or level. The concrete footing mixture should be poured around the entire pool panel perimeter at a depth of 152 to 203 mm (6 to 8 in.) and at the width of the over dig.
The next step is installing the coping. Corner sections should be installed first followed by the long lengths of coping. During this process, make sure the liner receptacle on the lower edge of the coping is flush with the top inside edge of the pool walls.
The next big job on day two is preparing the pool bottom. First, install the skimmer, then using the predetermined positions in the pool wall to receive the inlets, install the fittings so they are ready to receive the liner.
At this stage, the pool should be plumbed. There are a number of approved piping types and methods to perform this task; therefore, check the local building codes and builder preferences first. When all is said and done, it is highly recommended the plumbing lines be pressure tested prior to backfilling. Once the equipment has been plumbed, a certified electrical contractor can complete the connections for the pump and any lighting.
Finally, once the bond beam has been poured, following the manufacturer’s guidelines, layout the finished dimensions of the pool using pins and string. There should be a minimum of 51 mm (2 in.) between the finish grade strings and the excavation. Fill and pack low areas and voids with clean sand and trim out any roots or rocks. Then, string across the slope diagonally, from the deep end corner pins to the 51-mm vermiculite line on the bottom of the wall panels, making sure the lines are tight and not sagging. Once these lines are in place, the pool bottom can be trowelled.
| DO-IT-YOURSELFERS SHOULD BE WARNED |
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| The results can be tragic if a steel pool kit is installed improperly. While a do-it-yourselfer can buy a swimming pool over the Internet and hire someone to do the excavation, there are numerous factors that can be overlooked. For instance, the pool can be out of level; the excavation can be too deep or not deep enough; and, of course, water and drainage management is bound to be ignored. There have also been instances, for example, of insufficient concrete on the outside of the pool. Should this occur, water inside the pool will drain out and the ground pressure outside the pool will increase until the pool literally caves in. Those who are not aware of certain issues such as the disposal of excavated expansive soils are also often likely to use it as backfill, which can result in the movement of pool walls. Poor finishing of the pool base, wrinkles in the liner, and leaking plumbing lines can also make for a very unhappy pool experience if not done properly by a pool professional. Experienced pool installers receive extensive training on all of the potential issues regarding installation—from filtration and ground conditions to drainage and overall safety. This is why professionals are able to confidently provide warranties on their installations. A pool installed by a do-it-yourselfer will have no warranty on the work and an improper installation can void the manufacturer’s warranty should the installation affect the products themselves. |
Day three: Forming the pool bottom
Finishing the bottom of the pool can progress from either the shallow or the deep end; however, it is important to keep in mind the crew must be able to exit and enter the pool without disturbing any finished areas.
To do this, pour the pool base mixture directly into the excavation. At this point, the installation crew should use flat shovels for final placement. The pool bottom should maintain a minimum thickness of 38 to 51 mm (1.5 to 2 in.) throughout. Sharp edges or pockets where dirt can collect should be avoided. As the deep end slopes are completed and the hopper bottom is trowelled, remove the strings and pins, and clean any debris.
