If your pool or hot-tub deck turns slick every time it rains, the concrete itself is rarely the problem. The usual culprits are the sealer on top, a finish that was too smooth to begin with, and a green film that grows wherever water sits. In Olympia, where it rains from October to April, all three get plenty of help.
The short answer
- A glossy sealer is the most common cause of a slick deck, especially on stamped concrete.
- Smooth, troweled finishes have little grip once they’re wet.
- Water that sits in low spots grows algae and moss, and that film is slicker than any finish.
- Most slick decks can be fixed without tearing them out.
Cause 1: too much sealer
Sealer protects decorative concrete and brings out its color, but it also fills the surface texture and can leave a smooth film. Add coat after coat over the years and the deck gets slicker each time. Contractors interviewed by Concrete Decor, a trade magazine for decorative concrete, point to the sealer, more than the stamp pattern, as the usual reason stamped concrete around pools gets slippery.
A quick check: if the deck looks glossy and feels smooth when it’s dry, the sealer is the likely suspect.
Cause 2: a finish that was too smooth
A deck finished smooth with a steel trowel, or stamped with a flat, low-texture pattern, has very little to grip once water is on it. Around pools and hot tubs we use textured finishes (broom, knockdown or stamped) with a slip-resistant sealer, and we avoid smooth or glossy finishes near water.
Cause 3: water that sits, and what grows in it
Wet, shaded concrete in western Washington grows algae and moss, and a thin green film is slick even on a good texture. It shows up first where water sits: low spots, the edge along a planter bed, the side of the deck that never gets sun. A flat deck holds water all winter.
That’s why we slope pool and hot-tub decks away from the pool and the house, toward drains or the lawn. A deck that drains dries faster, and a deck that dries faster grows less.
Fixes, from smallest to biggest
- Clean it. Get the algae and moss off, and keep the shady side clean through the wet season. On some decks that’s the whole fix.
- Reseal with grip. For a deck that’s already slick, the contractors in Concrete Decor recommend a fresh coat of sealer with a slip-resistant additive mixed in. Grit helps but doesn’t make a surface slip-proof, and it wears with the sealer, so plan to renew it every few years. Thin, measured coats beat thick ones.
- Change the sealer. For owners most worried about slipping, the same contractors suggest a penetrating sealer, which soaks in and leaves no gloss on top.
- Fix the drainage. If water stands in the same spots after every storm, the fix may be the slope, not the surface.
- Replace the deck. When the slab is cracked, sinking or pitched toward the house, a new textured deck with the right slope is usually the better spend. We replace decks around existing pools with care around the coping and the pool shell.
Homeowner check: a 10-minute walk after the rain
- An hour after a rain, walk the deck and note every spot that still has standing water.
- Look for a green or dark film in the shady corners and along edges.
- On a dry day, look for a glossy, plastic-looking surface. Run your hand over it: glassy usually means heavy sealer, sandy means the texture is still doing its job.
- Check which way the deck falls. Water should run away from the house, not toward the back door.
What a new pool or hot-tub deck costs
In the Olympia area, a plain textured pool deck typically runs about $7–$12 per square foot, and a stamped or colored deck about $14–$25. Access, slope, demolition and drainage all affect the number, and your exact price comes in writing after a free on-site estimate.
Planning a hot tub as well? Here’s how thick a hot tub pad should be, and why the base under it matters as much as the concrete.
Slick deck? Get a straight answer
We’ll tell you honestly whether your deck needs a new sealer or a new slab. We’re licensed, bonded and insured in Washington, estimates are free and on site, and you get a written price before any work starts. See our pool decks page, or call (360) 469-6382.