Fix A Sunken Sidewalk Paver In A Snap With A Can Of Spray Foam

Pavers are an attractive and practical installation to customize walking paths around your property. But when they're uneven, functionality goes out the window. Sunken pavers aren't only unattractive to look at, but they also create unnecessary trip hazards and make everyday use more difficult, as any item rolled or dragged along the path can easily hang up on them. While you can often adjust pavers with gravel by prying them up and laying in new fill, large concrete and masonry slabs can be too cumbersome to remove entirely.

In these instances, DIYers looking for a straightforward, inexpensive, and lasting fix for sunken pavers can use spray foam to raise them back to the desired height. Injecting foam under the paver will fill any voids and provide support, giving you a solid, leveled surface without making you remove the piece. Spray foam can last over 80 years in ideal conditions, and the closed-cell variety can work indoors and outdoors. The polyurethane closed-cell composition can hold up well against moisture and won't leach chemicals into the surrounding soil, making it a sensible way to lift your pavers. Grab a few cans of spray expansion foam like Great Stuff Big Gap Filler (around $5 per can at Home Depot). You'll also need a hammer drill, a masonry bit, a few 2x4s, and a jack.

To fix your sunken paver, you'll drill holes through it and snake your spray foam canister nozzle into the holes to fill the void underneath. The hammer drill will help you effortlessly drive through the hard surface. If you don't have one, they're relatively cheap to rent (this Makita drill is only $27 to rent for four hours from Home Depot). You can use a standard cordless drill, but drilling the holes that way can take much more time and effort.

Drill several holes down through the paver, spacing them 6–8 inches apart. The holes must be wide enough for the spray foam canister's nozzle to fit. Next, jack up the paver to be flush with the surrounding pavers. YouTuber Jack of All Trades shows how to do this via boards connected to the paver with a long bolt. Alternatively, you can attach C-clamps to the paver (two to each side) and run boards through them. Jack them up to level the paver.

After lifting the paver, insert the spray foam nozzle into one of your pre-drilled holes and fill the void. Once foam comes out the sides under the paver and through the other pre-drilled holes, you'll know that section is full. Repeat this with the other drilled holes. With the void filled, let the foam cure for 8–24 hours (depending on product instructions) before applying weight to the paver. Trim the excess foam and fill the drilled holes with concrete filler, and your paver will be good as new!