Mid-Atlantic Pools

Dealing with heavy ground water conditions can sometimes be a nightmarish ordeal to a professional pool builder but it is easily resolved with experience. Building in solid clay normally provides very dry working conditions but in this article we will explore how it can create an ongoing headache for the homeowner long after the project is complete.

It's true, no matter where I have tried to build a below ground pool in Smithfield, Virginia I have had to deal with clay. I wish I could say that we have a clay soil mix but what little earthy soil I've found in my area wouldn't even be enough for a single potted plant. Smithfield clay is so bad that the deeper you go the worse it gets. I lovingly refer to our soil as art clay, those solid and moldable gray blocks you would get in a high school art class to sculpt a flower pot. For the professional pool contractor dry clay isn't necessarily a bad thing as long as they carefully excavate the shelf for the walls to sit on perfectly level. Otherwise the simplest repair is proven difficult whether they need to shave an inch or raise its elevation ever so slightly. Dealing with the leveling of a swimming pool wall structure isn't necessarily a long term concern especially when it is dealt with before the concrete footer is poured.

Clay presents a problem during the build if your job site endures extensive rain and no one prepared for ground water ahead of time. In a previous article I describe a few scenarios of how to deal with ground water from between two and four feet below ground level and again from four feet and deeper. It is the latter that I always consider when building in solid clay. By over digging the deep end by at least two feet and filling it up with stone you allow yourself an opportunity to bury a well point horizontally. Normally I will take a section of Schedule 40 PVC, cap it on one end and connect the other with flexible spa hose to allow it to be easily bent up the deep end side wall and underneath the installed wall. Before I burry the PVC I will take a ¼ inch drill bit and punch about twenty to thirty holes in a staggered fashion along the length of the rigid pipe. This acts as a pool builders well point in most cases as the traditional premade ones with fine slits tend to easily clog. Realize that there is no easy way to get to your well point after construction if it fails; therefore you are better off considering this tip based on experience.

So you now have a well point and it may have cost you an extra twelve hundred dollars in material. You may find yourself hating this article if it never rains during construction but if it does both you and your pool contractor will be happy to have it in place. Rainy construction days weren't the purpose of this article however, its post construction that I worry about when dealing with my clay in Smithfield. It's a little difficult to explain but no matter how long you let the over dig settle after backfilling your new pool it will never be the same. The clay has been disturbed and ground water will always seek the path of least resistance. Even years later that path will always be the back filled area around a pool that the water finds.

The true nuisance is the soaking rains that are followed by one or more gully washers. If and when that ground water finds the path of least resistance it never takes much of it to cause a vinyl liner to float or for a fiberglass pool to shift ever so slightly. For a vinyl liner pool that magic number could be as little as a few thousand gallons of water that finds its way around the walls of your pool before you risk the floating of a liner. And if that liner floats and goes unattended for even the shortest period of time you may find yourself replacing it when it stretches and won't fit into its original place.

Sometimes preparation for worst case scenarios can cost you what seems like an unnecessary expense. But in the case of preparing for dry ground my twelve hundred dollar investment has saved me and my clients tens of thousands of dollars in liner repairs and/or replacement. A well point will help you pull that extra water out from behind your swimming pool structure but what you really want to prevent damage is to learn how to control it even when you sleep.