Walkways are supposed to tilt away from a house to keep rainwater away from the foundation.

But apparently you think the tilt is increasing? There are companies that fix this easily through the use of foam - they squirt foam underneath somehow and as the foam expands and hardens it lifts the sidewalk. I don’t know what this procedure is called (mudjacking?) but maybe someone else will chime in.

I would just leave it for now. It still looks good. Just keep your eye on it, in case it keeps sinking.

Licensed general contractor here. Two different questions are hiding in yours, and the answer depends on which one it is.

A walk that slopes away from the house and has always sloped is fine; that is how it should be built. A walk whose tilt is increasing means the ground under one edge is moving, and the question is why. Three causes cover almost every case:

1. Water. A downspout discharging near the walk, or a low spot beside it, washes the fine soil out from under the slab over years. Look at where the roof water goes in a hard rain. This is the common one, and it is the one worth fixing before you lift anything, because a lifted slab over the same wet soil sinks again.

2. Backfill settling. If the walk runs across the trench that was dug for the foundation or a utility line, that soil was loose when it went in and can keep settling for a decade or more. Sinking that is worst in a band, not along the whole length, points here.

3. Tree roots or a burrow. Less common, easy to see once you look.

Structurally: the walk itself is not structural, so a sinking walk is not a foundation problem on its own. The thing to check is the house side. If the walk is sinking toward the foundation, water is now pooling against it. Look for a damp or stained foundation wall, cracks in the brick or block near the walk, and doors or windows near it that have started to stick. None of those: cosmetic, fix the drainage, and lift it when it bothers you. Any of those: get someone to look at the foundation, not the walk.

On the lift: mudjacking (a cement slurry) or polyjacking (expanding foam) both work on a sound slab. Foam is lighter and does not add load to already-soft soil, which is why most contractors use it now. Neither fixes the reason it sank. Downspout extensions and regrading first, lifting second, is the order.

Jared McCarley, Southeastern Renovation, licensed SC general contractor (CLG.127339)