Why Is My Patio Sinking?
A sinking patio typically drops toward the house — the exact opposite of where water should go. Here's why patios settle in Spokane and how a same-day lift restores slope without tearing out the pour.
Free On-Site Estimate · Serving Spokane & the Inland Northwest
Problem overview
What's actually happening.
Patios sit on some of the softest ground on the property: recently backfilled areas next to the foundation, spots that used to be lawn or bed, and stretches where irrigation keeps the soil damp year-round. That combination is a recipe for settlement in Spokane's climate.
The problem isn't usually the concrete — it's what's under it. Once fill under a patio compresses or washes out, the slab follows. And because patios are wide and flat, even a small drop shows up as visible ponding.
Foam leveling lifts a patio back to its original pitch, closes voids underneath, and gives you the same slab — level and shedding water again — the same day.
For the underlying service, see patio leveling. Serving Spokane, WA and the surrounding Inland Northwest. Ready to skip ahead? Request a free estimate.
Signs to watch for
How this problem shows up.
A visible tilt toward the house
Water no longer runs off away from the structure.
A gap between the patio and the house or a step
The slab has pulled away as it dropped.
Puddles that persist after rain or watering
The original slope has flattened or reversed.
Cracks along the edges or across the middle
Unsupported sections are flexing under load.
Furniture and grills no longer sit level
The tilt is visible in the objects on the slab.
Landscaping washing over the edge
Mulch or soil is migrating across a dropped edge.
Common causes
Why it happens in the Inland Northwest.
Spokane's freeze/thaw cycles, clay-and-silt soils, and heavy seasonal runoff produce a fairly predictable set of root causes.
Backfill next to the foundation compacting
The most common cause on attached patios in Spokane.
Downspout and irrigation water saturating the subgrade
Concentrated water sources undermine one side of the slab.
Clay soils cycling wet-to-dry
Common across the Inland Northwest — repeated shrink/swell separates soil from slab.
Freeze/thaw heave
Wet subgrade cycles create voids and edge drops each winter.
Old landscape features under the pour
Buried planter boxes, tree stumps, or wood forms decompose over time and drop the slab.
How to determine severity
Read your slab like a pro.
A quick self-triage. When in doubt, request a free on-site walkthrough.
- Small tilt, no ponding: cosmetic. Cheapest time to fix.
- Ponding within 2 feet of the house or door: high priority. Water is now heading toward the foundation.
- 1+ inch drop plus cracks: significant — the slab is flexing.
- Slab is rocking or hollow-sounding: real void underneath, level soon.
- Slab is broken into pieces: partial replacement for the broken sections.
Not sure how bad it is?
Get a free walkthrough before it gets worse.
We'll measure the drop, check for voids, evaluate the drainage, and give you an honest recommendation — including whether it's a leveling job or something else.
Why waiting makes it worse
Settlement doesn't fix itself.
Every cause listed above keeps working whether or not the slab is addressed.
- Water pushed toward the foundation is a much more expensive problem than the patio.
- Freeze/thaw damages a wet, unsupported slab quickly.
- The void grows and the required lift grows with it.
- Landscaping keeps migrating over the low edge.
- Furniture wobbles worsen and the slab becomes less useable each season.
Repair options
What are your choices?
An honest comparison — the right fix depends on the slab, the cause, and the goal.
Polyurethane foam leveling
Foam injected under the low areas restores slope and stabilizes the subgrade.
Drainage and grading correction
Extend downspouts, adjust beds, redirect sprinklers — usually part of the same project.
Overlay resurfacing
Cosmetic only. Doesn't correct slope; adds weight to an already-weak subgrade.
Full replacement
Reserved for patios that are structurally failing or where the slope can't be restored by lifting.
Why polyurethane foam usually wins
The best fit for the vast majority of Spokane slabs.
- Cures in about 15 minutes — you can drive or walk on the slab the same day.
- Closed-cell foam doesn't wash out or absorb water like sand or slurry-based methods.
- Injection holes are dime-sized, not the golf-ball ports left by mudjacking.
- Lightweight — adds roughly 4 lbs per cubic foot vs. 100+ lbs for mud slurry, so it won't re-settle weak soil.
- Stabilizes the underlying soil at the same time it lifts the slab.
For a full comparison, see polyurethane foam vs. mudjacking in the Learning Center.
When replacement may be necessary
The honest cases where leveling isn't the right call.
- The slab is crumbling, spalling apart, or shattered with structural cracks — there's no solid piece left to lift.
- The concrete is very thin (below ~3 inches) and would crack under the lift pressure.
- You're changing the layout — widening a driveway, moving a patio, adding a new pour.
- Reinforcement is severely rusted and the slab is delaminating.
More detail in concrete leveling vs. replacement.
Frequently asked questions
Straight answers from Spokane homeowners.
- Can you lift a stamped or colored patio?
- Yes. Injection holes are dime-sized and typically blend into a stamp pattern or are patched to match.
- Will landscaping have to be removed?
- Almost never — no excavation and no heavy equipment needed.
- How long does the project take?
- Most residential patios are lifted in half a day. You can use it the same evening.
- Is it a foundation problem?
- Almost always no. Patios sit on independent soil pads and move separately from the house.
- How long does the lift last?
- Indefinitely, provided drainage is corrected. Foam doesn't degrade or compress.
- Do you handle covered patios?
- Yes — the technique works the same. We work around posts and columns as needed.
- Will my grill and furniture leave marks after the lift?
- Only where they were before. The lift itself doesn't add wear.
- Do you serve Coeur d'Alene and Post Falls?
- Yes — patio leveling throughout the Inland Northwest.
Related services
Explore the services that solve this problem.
Considering budget? Patio leveling cost in Spokane.
Related problems
Other homeowner questions we hear.
From the Learning Center
Related reading before you request an estimate.
Free estimate — no obligation
Fix it before the next wet season.
Settlement compounds. Every rainstorm and freeze/thaw cycle makes the void bigger. Get an honest walkthrough now and know exactly what your options are.
Lift it — don't replace it.
Have questions about your concrete? Need advice? Want a free estimate? We're here to help. Concrete leveling saves the slab you already have, at a fraction of the cost of replacement.
- Often less costly and less disruptive than tear-out and replacement
- Repair before replacement when appropriate
- Modern concrete lifting methods
- Clear recommendations — no pressure, no upsells
Free Estimates · Spokane-Focused Service · Clear Recommendations