Why Is Water Pooling On My Patio?
A patio is supposed to shed water away from the house. When it starts pooling — especially near the back door or foundation — the slab has settled and the drainage plane is inverted.
Free On-Site Estimate · Serving Spokane & the Inland Northwest
Problem overview
What's actually happening.
Backyard patios in the Inland Northwest take a beating from irrigation, roof runoff, and expansive soils cycling wet-to-dry every season. When a patio starts holding water, it's rarely the finish — it's the slope.
Most residential patios were poured with a slight pitch away from the house. Two or three degrees is enough to move rainwater out. When settlement takes that away, water reverses direction and pools right where you don't want it: against the siding, the back door, or a walkout basement.
The urgency here is higher than a driveway puddle. Water at a foundation edge is a foundation problem waiting to happen, and every rainstorm is making the void under the slab a little bigger.
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.
Puddles near the house wall or back door
The slab has tipped back toward the structure — the highest-priority version of this problem.
Water sits after every rain, in the same footprint
That footprint is a map of your settled area.
Mildew or mud line at the wall base
Repeated exposure is leaving a residue where water is standing.
Sunken corner or dip near a downspout
Concentrated water source has washed out that section of subgrade.
Efflorescence blooming on the slab
Water is soaking into the concrete and depositing minerals as it dries.
Furniture and grill no longer sit level
The slope is now visible in the way things sit on the surface.
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.
Settled subgrade under the patio
The soil pad has compressed unevenly and the slab is following it — usually toward the house.
Downspouts discharging onto or beside the patio
The most common cause we see in Spokane. Concentrated roof water saturates and erodes the soil below.
Sprinkler and irrigation over-saturation
Beds against the patio soften the soil under the edge and drop the slab a fraction each season.
Expansive clay soils
Common in parts of Spokane, Post Falls, and Coeur d'Alene. Repeated shrink/swell cycles pull soil away from the slab.
Poor initial slope
Occasionally a patio was poured with too little pitch. Small settlement then flips the drainage direction quickly.
How to determine severity
Read your slab like a pro.
A quick self-triage. When in doubt, request a free on-site walkthrough.
- Small puddle in a low corner, away from the house: cosmetic but worth tracking.
- Standing water within 2 feet of the foundation or door threshold: high priority — foundation and interior water are next.
- Water crossing the threshold or reaching the walkout: emergency territory. Level and correct drainage now.
- Cracks running from the low spot into the slab: the pour is now flexing and the void is meaningful.
- Efflorescence or interior moisture on the wall behind the patio: the water is finding a path in.
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 at the wall keeps moving toward the foundation and into any waterproofing weakness.
- Freeze cycles on the wet slab spall the surface faster.
- The subgrade continues to erode under a saturated slab — the void grows every rain.
- Interior moisture, basement seepage, or wall efflorescence often follow within a season or two.
- The lift needed grows, and grading the surrounding beds becomes part of the fix.
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 to lift the patio back to its original pitch — away from the house.
Drainage correction (downspouts, grade, drains)
Address the water source that caused the settlement. Almost always combined with leveling.
Overlay or resurfacing
Cosmetic only. Doesn't fix slope, and often accelerates issues by adding weight to a compromised subgrade.
Replacement with corrected slope
Reserved for slabs that are structurally failing or where lifting can't restore proper pitch.
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.
- How urgent is water pooling near my house?
- High. Any pooling within a couple of feet of the foundation should be corrected before the next wet season.
- Can leveling really tip the patio back the other direction?
- Yes — that's exactly what it does. Foam is placed in the pattern needed to restore slope away from the house.
- Will landscaping have to come out?
- Almost never. Foam injection is minimally invasive — no excavation, small holes, no heavy equipment.
- What if the patio is stamped or colored?
- Foam works on stamped and colored slabs. Injection holes are dime-sized and blend into the pattern in most cases.
- Do I need to fix the downspouts too?
- Yes, ideally at the same time. Lifting without addressing the source of concentrated water sets up a repeat.
- How soon can I put furniture back on it?
- Within an hour or two. The foam cures fast and there's no drying period.
- Is this a job for a foundation contractor or a concrete leveler?
- If the slab has moved but the house hasn't, this is concrete leveling. Foundation contractors get involved when the structure itself has moved.
- Do you work in Spokane Valley, Liberty Lake, and Coeur d'Alene?
- Yes — patio leveling across 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