Last Updated on October 20, 2026 by Umar Farooq
Pavers sinking next to house walls are almost always sitting on loose backfill, the soil that was dug out for the foundation and shovelled back in. That soil settles, the base follows it, and the pavers follow the base. Before you lift anything, make sure water is not running toward the wall, because water makes the settling worse. Then lift the dip, rebuild the base in thin lifts and relay the same pavers.
The strip along a wall is where patio questions go to get awkward. It is also usually a soil problem rather than a house problem, which is the better kind to have.
Why the strip along the wall drops first
When a house is built, the crew digs a hole bigger than the foundation, builds the walls and then fills the gap around them. Soil that has been dug up never goes back as dense as it was. The City of Smithville's public works director put it plainly in a staff report on trench backfill: "Soil is never as compact as it is in a virgin state." That report was about trenches under streets, but the soil does not know the difference.
The patio crew then digs into that strip again to set the base, and a light plate compactor often cannot pack a deep, loose strip firmly. Homeowner answers in a Hometalk thread describe exactly this: backfill that settled after the patio went in, with the pavers dropping along with it.
I went looking for how many years backfill keeps settling and found forum posts and contractor blogs with confident numbers and no study behind them. So I will not give you one.
Is it the soil, the water or the house?
Read the shape of the dip before you dig.
| What you see | Most likely cause |
|---|---|
| Dip runs along the wall and ends where the old foundation hole ended | Settled backfill |
| Dip sits under a downspout or at the low end of a slope | Water washing the base out (see paver base washout) |
| Whole patio falls toward the wall | Wrong slope (see paver patio slope) |
| Wall cracks, sticking doors or windows, or the gap is growing on the house side too | Stop. This is a question for a structural engineer, not a patio repair |
Colonial Newburgh, a contractor, calls water flowing toward the foundation "the most urgent concern" on a sinking patio, and I agree. Run a hose along the patio and watch where it goes. If it ends up at the wall, fix that first.
Water first: slope and downspouts
The model building code asks for the ground to fall at least 6 inches within the first 10 feet from the foundation, and for hard surfaces within 10 feet to slope at least 2 percent away (IRC R401.3, which varies by local adoption, so check your building department). The building-science guide from Pacific Northwest National Laboratory says the same and adds that where the lot will not allow the slope, drains at the base of the patio are an option.
Roof water is the cheapest thing to fix. A downspout that empties onto the strip feeds the settling every storm. Extend it or pipe it away; downspout drain under patio shows how.
Rebuild the strip, not just the pavers
This is where my one opinion lives. Compact the base in lifts. A thick layer compacted once from the top is a hard crust over loose stone, and next to a wall that crust sits on top of soil that is already loose. ICPI's 4 to 6 inch lift figure assumes a 7,000 lbf plate, and the same sentence says smaller plates need thinner lifts. PennDOT's trench guidance allows 8 inches per lift with vibratory equipment and 4 inches with other methods. Different bodies, different numbers, so start thin.
- Call 811 first. Service lines enter the house right here. Hand-dig near any marks. See call 811 before digging.
- Lift the dip plus one or two rows of sound pavers on each side, and stack them in order.
- Dig out the base and soft soil to firm ground. Do not put topsoil back; as a repair guide from Agrio points out, organic matter rots and the patch settles again.
- Re-compact the subgrade, then add crushed stone in thin lifts, damp, with a hand tamper tight to the wall (a rented jumping jack for the long runs; see jumping jack vs plate compactor).
- Set the slope in the base, add about 1 inch of screeded, uncompacted bedding sand, and relay the pavers 1/8 to 1/4 inch proud for settlement (CMHA).
Rent the tamper before you hire anyone; moving a few feet of pavers is a weekend, not a crew. Hire when the area is large, a retaining wall is involved, or the wall itself is cracking.
What will not fix it
- More bedding sand. The sand bed is 1 inch. CMHA says an installer cannot correct base deficiencies with extra bedding sand. Two inches in a dip compresses more than one inch everywhere else.
- Topsoil in the hole. It rots and consolidates.
- Caulk or sealer in the gap. That treats the surface; the soil is still moving.
Keep water off the strip and let it have the last word
Pavers sinking next to house walls stop sinking when the backfill under them is dense and the water goes elsewhere. Do the downspout first, rebuild in thin lifts, and check the rest of the foundation line for the same dip before you pack up the tamper. The wall has been there longer than the patio and it is not moving. The soil beside it is the one that needed convincing.
FAQ
Why are my pavers sinking next to my house?
Usually because the soil beside the foundation was dug and refilled during construction and never became as dense as the ground around it. Roof water running onto the strip speeds it up.
Is a sunken patio next to the house a foundation problem?
Often it is only the soil beside the wall. If the house itself shows cracks, sticking doors or windows, or the gap is growing on the house side as well, have a structural engineer look at it.
Can I just add sand under the sunken pavers?
No. The sand bed is a 1 inch layer, and extra sand in a dip compresses unevenly and brings the dip back. Fix the base and soil under it.
How far out from the house should I dig?
Lift past the dip and into pavers that are sitting correctly, one or two rows more. I found no source that gives a distance for backfill zones, because house excavations vary.
Will the pavers keep sinking after I fix it?
Not if the backfill is rebuilt in thin compacted lifts and water is directed away. I could not find a verified timeline for further settling; recheck with a straightedge after the first season.
