One of the most important parts of the inground pool installation is making sure that your pool walls are level. A pool that’s even an inch off level is very noticeable, with uneven water level and deck slabs.
Using any type of level - a transit level, builders transit or a laser level all will do the job well, it is whatever you have access to during your pool construction. One does not do a better job than another. The laser may be the easiest as all you do is move what ever you're leveling up or down and listen to the beep of the laser and you’ll know when its perfectly level. A builder's transit allows you to move horizontally, in addition to side to side.
Whichever type of equipment you use to ensure a level pool, you'll need it during nearly every phase of your inground pool kit construction.
When you'll Need a Transit
- During pool layout, to establish the finished grade of the pool deck and backyard, before you dig.
- During the pool dig, to set the correct height of the pool shelf, the area the pool walls sit upon.
- During wall panel setup, to ensure that they are all the same exact height.
- After pouring the concrete collar, or pool foundation, to check wall panels again.
- After backfilling the pool, to set the grade and pitch of your pool deck and terrain around your pool.
Setting up a Transit
- Set the tripod at a point around the pool. Extend the legs so the mounting plate is just below the pool wall, and lock the locking screws. Push the legs firmly into the dirt.
- Set the transit carefully on the mounting plate. Turn the locking screw underneath until snug.
- Level the mounting plate to the center of the vial bubble, by adjusting the sliding legs slightly or the leveling screws, until the bubble is perfectly centered.
- Level the transit by turning the horizontal and vertical tangent screws until the bubble or indicator inside the transit shows level. Turn 90 degrees and do it again.
Using a Transit
Pool Layout: The pool needs to sit above the surrounding ground, so that storm waters run around it, and so that if the pool were to overflow, it would run-off the property. Use the transit to establish a benchmark for the height of the pool deck, at the pool wall. It's usually necessary to reference an existing point, say the back patio or walkway. If your property has hills and swales, use the transit to not only establish the pool elevation, but to grade the land, so that waters run around the pool, towards storm drains or basins.
Pool Excavation: Your excavator may have a transit with them. He will need someone to use the transit during the dig, and another person to hold a measuring stick to make sure the depth is accurate. After your dig is complete and before you start setting your wall panels, use the transit to 'shoot' all around the pool shelf getting it as close as you can to being level.
Pool Wall Assembly: Assemble the wall panels, leveling as you go at the top of the wall on the flange, panel by panel. Once all the panels are assembled and your A-Frame braces are attached and staked into the ground and your steps are in place, you are ready to square up the pool. Take cross corner measurements, and shoot the transit from corner to corner, end to end and side to side, checking all panels. You can dig under panels that are too high, or shim up panels that are too low.
Once the tops of the panels are level, use a carpenter's level to make sure the panels are plumb, or vertically straight. Use a three foot level and place it on the vertical face of the wall panel (going up and down). The bubble on your level should be dead center for all wall panels. If not, make brace adjustments to push panels in or lean panels back. Once the panels are all plumb, use a carpenter's level to check the top of each panel for dead center level.
Pool Steps: These are leveled the same way using the transit at the front inside of the steps, but the steps need to pitch backwards from front to back. Use your carpenter's level on the side top lip of the step and drop the rear of the step down ½ bubble on both sides. Secure the step to adjacent wall panels, maintaining the backwards pitch of 1/2 bubble, or about 1 inch on both rear corners.
Concrete Collar: The next use of a transit during pool kit construction, is after you pour the concrete collar. Check the tops of each panel joint for the correct height, and use the carpenters level to make sure the front of the panel is plumb, or 90° vertical. At this point the concrete is wet, so you can still make any minor panel adjustments to the panel level and plumb. Once the concrete hardens, you lose the opportunity to make wall and step adjustments.
Alternatives to Using a Transit Level
There are other ways to do all this leveling, without a rented transit level, at $125 per week. It will take more time, and may not be as accurate, but you can do this with a carpenter's level and a plumb bob. You would be leveling from panel top to panel top, one by one - making sure never to adjust the height on the panel you just leveled, just the panel in front of it. A plumb bob or a carpenter's level could be used to make sure the front of the panel is plumb. You could also use a line level and string to level panel by panel again also. Small laser levelers can also be used, shooting from the top of known level and plumb wall panels to other panels.
In Conclusion: It is well worth spending the time to do all these steps and get everything as perfect as you can as it does have an huge effect on how the total pool looks after it is all complete. Take the time to learn how to properly use this precise piece of engineering equipment. Read the owner's manual.
However you do this, I can’t stress enough check level again and again during your DIY pool kit construction project, you’ll be glad you did.
SPP Pool Expert