Summer is Swimming Pool Season: Is it a Saltwater Pool?
Rich Cofoid, Council Director

Summer is swimming pool season. For a sealer manufacturer, it is also the season for increased tech calls about sealers used on decorative pool decks.

Amongst the various pool water sanitation methods (chlorine, UV, ozone, and salt), the salt method is the fastest growing, whether it’s new builds or folks replacing traditional chlorine equipment for the saltwater chlorination method. The advantages of a saltwater pool are many: fewer chemicals are used, so lower chemical costs, it's better for your skin and hair, easier on towels and swimsuits, lower maintenance, and more. However, what many people fail to realize is the corrosiveness of the salt water. It is not just hard on outdoor furniture and pool fixtures, but it can wreak havoc on your pool deck, whether it is natural stone or concrete.

This week alone (and it is Tuesday as I write this) I have fielded three calls about supposed sealer failure- sealer delaminating. The first question I ask after I’m told it is a pool deck is “Is it a saltwater pool”? All three cases this week have been YES. So, why don’t acrylic sealers stand up to salt? They do! It is not the sealer but the concrete under the sealer that causes most issues. The problems typically start around a control joint or where the concrete slab meets the pool coping. Usually, it is worse (or first noticed) when people get out of the pool as the saltwater drips off the body. Whether it’s a control joint or a small crack or pinhole in the film of the sealer, salt water eventually migrates under the sealer it starts attacking the concrete underneath. When the concrete deteriorates it brings the sealer with it. The delamination spreads with time.

It is not so much a sealer problem as it is a concrete problem, or a saltwater meets concrete problem.

So, what’s the fix? First, be aware of potential issues and ask the client what you are dealing with before you begin a decorative project. If it’s a saltwater pool, you might want to have a disclaimer in your contract (I’m no lawyer, so not legal advice, just a suggestion). Next, we have found the best sealer is either a penetrating sealer, like a silane or siloxane, or a combination of penetrating sealer with a solvent-based acrylic. If you use this combo, the acrylic must be solvent-based as the penetrating sealer will prevent a water-based acrylic from sticking. If you are working in a state with strict VOC regs, then this combo won’t be an option for you, sorry.

We run across this phenomenon with spray down/knock down systems as well. The saltwater gets under the sealer AND texture, attacks the concrete, and everything delaminates. As always, check with the manufacturer of your decorative chemistry before beginning a saltwater pool deck to ascertain their recommendations.