Using Vermiculite Or Perlite Under A Pool

Vermiculite and perlite are commonly used to prevent soil compaction in gardens or potted plants. Both of these materials are found in the garden section of most home improvement stores as well as many local garden shops. They both are readily available in small quantities without trouble, but larger amounts may be difficult to find.

In the old days (60’s- early 80’s) of above ground pool building, both vermiculite and perlite were a common sight. Pool installers of the era used to stock up on these materials as most pool installations were using them during construction. In those days 50lb bags of either material were common place.

Vermiculite Or Perlite Under The Pool Liner

How vermiculite and perlite were used is very similar. After reaching the point in which the pool wall was up and the final ground preparation and grooming was completed, the vermiculite or perlite was added. These materials, either one or the other, were poured into the pool. As a general guess I would say at least 200lbs. of perlite or vermiculite were used on an average 24′ above ground pool. We would use enough to completely cover the bottom of the pool in 2″-3″ inches of material. Adding this much perlite at one time will make a cloud of dust that will make you cough up a lung, so wear a mask if you are attempting this.

Liner Protection And More

The idea was that the addition of vermiculite or perlite to the floor of the above ground pool, was going to protect the vinyl and make the pool bottom softer. Both of these materials feel completely different under your feet. Vermiculite feels like the liner is very thick and spongy at first, but once it is packed down from water weight and feet it feels hard like clay. While the perlite feels like little pebbles under the liner, not soft or spongy at all or ever.

What To Put Under Your Pool

I have seen the long term effects of both vermiculite and perlite under pool liners for above ground pools, and I say stay away from both of these materials. Both pack down very hard and will not let water pass through them. This is no different than using plastic sheeting, Styrofoam, roofing tar paper or other non breathable material under your pool. They all have the same ill effect on an above ground pool, they all cause premature corrosion of the pool wall and frame.

I highly recommend the use of Armor Shield pool floor pad under any above ground pool. It stops critters from damaging your pool liner, it prevents sharp objects from coming through the vinyl and best of all it is breatheable. In fact, using Armor Shield along with your new above ground pool liner will add to Swimline’s pool liner warranty when purchased together. This modern material is a much better choice than any of the different material mentioned above.
Good luck with your swimming pool project!!

Thank you for reading this blog and I hope it answers some questions for you.