Patio pavers sinking or uneven
moderate 2–4 h
Tools: two flat screwdrivers or a paver extractor, rubber mallet, hand tamper, straight board and level, broom, garden hose · Materials: coarse bedding sand, crushed stone base (if the base has washed out), polymeric jointing sand
Steps
- Pour a bucket of water on the patio and watch where it runs and where it sits; the sunken area is usually where water enters the base, and the fix includes getting that water elsewhere.
- Lift the sunken pavers with two screwdrivers or an extractor, working outward from the low point, and stack them in order.
- Look at what is underneath: sand only is the usual case; if the stone base has washed out or there is a void, add crushed stone, dampen it and compact it in thin layers.
- Screed fresh bedding sand level with a board, slightly proud of the surrounding pavers, and set the pavers back with a mallet until flush.
- Sweep polymeric sand into the joints, blow the surface clean, and mist it lightly to set — this stops the sand washing out again.
- Redirect the downspout or add edging where water was entering, and check the patio with a level: it should fall about 2 cm per metre (¼ inch per foot) away from the house.
Stop and call a pro if
- the dip covers more than a few square metres or the whole patio has lost its slope — that is a re-lay
- a tree root is lifting the pavers or the sinking is next to a foundation crack
- the patio is on a slope with a retaining edge that is moving
What a pro does that you can't
A hardscaper lifts and re-bases a whole patio with compacted stone and proper slope, adds drainage where water is undermining it, and re-lays the pavers with edge restraint so they stay put.
DIY cost: $30–80 in sand and polymeric sand; $60–150 with stone base