A sunken pool deck is one of the most common concrete failures we see in Phoenix. The soil beneath the deck washes out from pool overflow, irrigation, monsoon runoff, and backwash lines — and once the void is there, the slab has nothing to rest on.
What pool deck failure looks like
- The deck has separated from the coping with a visible gap or lip
- The deck is sloping toward the pool instead of away from it
- One section has dropped while the rest of the deck is still in place
- Cracking running parallel to the pool edge
- Pavers or tile lifting where the slab beneath them moved
How we lift pool decks
Polyurethane foam injection is the right tool here. Mudjacking puts heavy slurry under a slab that is already sitting on washed-out soil — it can make the underlying problem worse. Foam is light (2–4 lb/cubic foot vs. 100+ for mudjack slurry), waterproof, and dimensionally stable.
- We map the deck and identify the void areas with sounding
- We drill penny-sized injection points (5/8")
- We inject foam — it expands, fills voids, compacts the soil, lifts the slab
- Laser-level monitoring stops the lift at original grade or original pitch away from the pool
- We patch the holes — color matched as best we can to existing texture
We do not drain the pool. We do not touch the pool plumbing. The work happens entirely from the deck side.
Why Phoenix pool decks settle
A few specific Phoenix factors stack the deck against pool decks (no pun intended):
- Pool overflow + monsoons. Heavy backyard water events erode soil under the deck.
- Backwash lines. Old or buried backwash lines slowly soak the soil under the deck for years.
- Expansive clay. Wet/dry cycles in Valley clay create voids as the soil shrinks back.
- Compaction shortcuts. Decks added after the original build often sit on lightly compacted soil.
Pool deck leveling cost
Most Phoenix pool decks run $1,500 to $4,500. Severity, square footage, and how many access points we need drive the price. Pool deck replacement runs $10,000–$25,000 depending on size and finish — and you cannot use the pool for days.