This is one of the most frequently asked questions when it comes to purchasing an above ground pool. And the answer is almost always situational. As sand will always be more firm and structured in the long run, vermiculite is perfect for the smaller pools on a budget.
Sparkle Pool Service has been building pools on Long Island for over 35 years, and have that much experience with vermiculite-bottom pools. Over these years, more and more pool buyers have been switching to sand based pools, as the floor itself is much more solid. We even do jobs where people decide to convert from vermiculite to sand because, overtime, the vermiculite bottom becomes extremely uneven.
If you are thinking about doing a vermiculite bottom, you are going to want to make sure that there are not many tree roots near the area that you want to put your pool. What happens is that when you lay the vermiculite down and hang your liner over it, you can never get it flat, and will almost always settle uneven. The vermiculite also retains moisture extremely well, which tends to attract roots over time. After a year or sometimes even sooner..roots from nearby trees can grow up to the surface to the point where you can see and feel them at the bottom of your pool. And in some instances they can even create pinholes in your liner and cause leaks. Now we’re not saying this to scare you if you have or already purchased a vermiculite bottom, but just to inform you and keep you aware of the future possibilities. We have also seen 15 year old vermiculite bottoms that still look perfect. Just be aware of the type of ground that you have in your yard and any nearby trees.
The difference that sand has, when professionally installed, is that you have a much more smoother, flatter surface. Generally you use enough sand, based on the size of the pool, to create a 2-4 inch base of sand. We rake out the bottom, soak and tamp every square inch of the pool, and then broom it out nice and even. This creates that strong, sturdy, smooth bottom you want under your liner. Finally, the main point of using sand is that it suffocates anything growing underneath it. So, unlike vermiculite, no roots or grass can grow through the bottom and cause damage to your liner.
Vermiculite is perfect ini certain situations, just make sure to do your research and make the right decision for life of your pool and pool liner. If you have any questions at all please feel free to reach out to us on any social media or by phone at 631-981-0685.