Last Updated on October 20, 2026 by Umar Farooq
Pavers sinking at bottom of steps is usually a water problem first and a base problem second. The foot of a flight is the lowest point that rain from the steps, the roof and the walkway can reach, and it often sits on backfill that was dug up when the steps were built. Before you lift anything, watch where water goes at the foot of the steps, measure how far the landing has dropped, and check that the bottom riser is still within 3/8 inch of the others.
Pavers sinking at bottom of steps: the foot of a flight is where water ends up
Rochester Concrete Products lists the usual water sources behind sinking pavers as downspouts that discharge near the paving, grading that sends water toward it, irrigation, and open joints, and it adds that runoff collects against retaining walls, steps and foundations (Rochester Concrete Products). That is exactly the geometry at the foot of a flight: a vertical face, a low point and a surface that has to carry every footstep. (Water is not clever. It goes downhill and waits.)
Carolina Paver, a South Carolina contractor, makes the same point about downspouts and edges. Water that gets under pavers washes the fines and bedding sand out of the base, which is why sinking so often shows up near downspouts and edges, and loose backfill alongside the paving leaves the edge nothing to lean on (Carolina Paver). Both are commercial sources, and I could not find a study that ranks these causes by how often each happens, so the table below is my own sorting.
| Where the dip is | Likely cause | First check |
|---|---|---|
| Hugging the foot of the riser, water stands after rain | Runoff off the steps or a downspout, plus a base washed out | Run a hose from the top step and watch where it goes |
| Hugging the riser, dry, with a gap at the face | Backfill under the landing settled | How the steps were built, and what was dug there |
| Where people turn or pause | A base too thin or loose under concentrated foot traffic | Probe the dip after lifting a few pavers |
| At the far edge of the landing | Edge restraint failed or the edge is eroding | Push on the border row |
Why the bottom riser matters more than the dip
The dip is the visible fault. The hidden one is the step height. When the landing drops, the first riser gets taller than the rest. The model residential code allows no more than 3/8 inch of difference between the largest and smallest riser in a flight (IRC R311.7.5.1), and your feet will notice before your tape does. As an example, with 6 inch risers, a landing that sank 1/2 inch makes the bottom riser 6 1/2 inches: that is my own arithmetic, and it is past the limit.
So measure it. Lay a straightedge on the first tread, hold a tape from its underside to the landing, and compare with the other risers. Local codes differ, so ask your building department if the steps serve a door. A sunken landing that makes someone miss the bottom step is a safety repair, not a cosmetic one.
Send the water somewhere else first
My one opinion here: fix the water before you fix the pavers. A relaid landing that still has a downspout dumping beside it is a short-term repair with extra steps. It costs little to check and nothing to ignore until the next storm.
- Watch it work. Run a hose at the top of the steps and at any nearby downspout for a few minutes, and watch where water travels. This is my own test, not a published one.
- Move roof water. Extend the downspout well away, or connect it to a buried line. Downspout drain under patio covers piping it out.
- Check the slope. The landing should fall away from the steps by about 1/4 inch per foot (2%), the IRC figure for hard surfaces near a house (R401.3). If it falls toward the riser, water will always end up there.
- Look near the house wall. The clearance and grade rules there are in pavers around house foundation.
Rebuild the landing from the base up
If the water is fixed and the landing is still low, lift and relay it, with a base that actually matches the rest of the steps. The general method is in how to fix sunken pavers. At the foot of steps, a few details change.
- Lift past the dip. Take up the dipped pavers and at least one row beyond, so the repair blends in. Stack them in order.
- Dig to firm soil. Unilock says never to build steps over topsoil, and that the native soil should be well settled and not recently disturbed. If you find loose backfill or topsoil at the foot of the steps, dig it out.
- Add fabric on clay. Unilock also places a non-woven filter fabric over native soil in the footprint before the stone. It keeps wet clay from working up into the base (Unilock, how to build steps).
- Compact crushed stone in thin lifts. Use a hand tamper close to the riser and a small plate beyond it. Unilock calls compaction of the gravel base the most important part of the work.
- Bed and relay. Screed 1 inch of concrete sand, set the pavers 1/8 to 1/4 inch high for settlement (CMHA), compact and re-sand. ICPI's limit on lippage between pedestrian pavers is 1/8 inch, so check each one.
- Pitch it away from the steps as you go, rather than leveling it flat.
When the steps or the wall are moving too
Sometimes the landing is not the first thing to sink. If the bottom riser block tilts or shifts, the gap at the riser face widens, the steps lean, or you see cracks in the house wall or foundation, stop. Rochester's guide lists movement near steps, retaining walls and foundations as a reason to call a professional. A landing relay will not hold on a base that is still moving. Photograph the steps with a tape in the frame, and record when the gap grows.
If the problem is a loose cap or tread rather than a sinking landing, see loose paver steps for the rock test and the fixes by piece.
Repairs that only look finished
- Pouring sand into the dip. CMHA's application guide says not to use bedding sand to fill depressions in the base. They show through the surface.
- Mortar or grout in the joints at the bottom. Pavers are a flexible system. Rigid fill tends to crack when the base moves.
- Gluing the landing pavers. Glue is for caps and treads. The landing needs sand and a base.
- Leaving the downspout alone. The first heavy rain will find the same spot.
- Ignoring the riser measurement. A level new landing next to a taller bottom riser can still fail the 3/8 inch rule.
Build the foot of the steps like part of the steps
The landing is not the patio. It sits next to heavy blocks and over ground that was disturbed. Dig through the topsoil, compact the fill in thin lifts, bury the first course, pitch the landing away at 2%, and keep roof water off it. If you are building new steps, how to build steps with pavers covers the whole sequence.
Water first, base second, riser check last
The foot of the steps drops where water and traffic meet loose fill. Move the water, rebuild the landing on firm soil and stone in thin lifts, and check the bottom riser against the rest before you call it done. The best repair is one nobody notices, including the people who walk over it every morning.
FAQ
Why are my pavers sinking at the bottom of my steps?
Usually water or loose backfill. Runoff off the steps or a downspout collects at the lowest point and washes out the base, and fill dug up during construction settles. Check where water goes first.
Can I just add sand to the low spot at the bottom of steps?
No. Extra sand makes a soft layer that settles again, and CMHA says not to use it to fill depressions in the base. Rebuild the base with crushed stone instead.
Why is my bottom step taller than the others now?
The landing has sunk, which increases the height of the first riser. The model code allows only 3/8 inch of variation in riser height within a flight, so measure it.
How do I stop water pooling at the foot of steps?
Extend or pipe away any downspout, pitch the landing away from the steps by about 1/4 inch per foot, and check the grade near the house wall.
Is a sunken landing at the bottom of steps a foundation problem?
Not usually, but check. If the steps lean, the gap at the riser keeps growing, or the house wall has cracks, have a professional look.
How long should I wait before relaying a sunken landing?
I found no published waiting time. Fix the water first, measure the dip again after a few rains, and relay when it has stopped changing.
