SlabGasket Installation Tips

Expansion Joint Repair

SlabGasket comes in many sizes & two colors:  ½” SHORTY, ½” STANDARD, 5/8”, ¾” SHORTY, ¾” STANDARD, 7/8” SHORTY, 7/8” STANDARD, 1”, 1-1/8”,1-1/4”, 1-3/8”, 1-5/8” SHORTY, 1-5/8” STANDARD, 1-3/4”, 1-7/8″, 2″

It is recommended that you obtain a SlabGasket sample kit before you place your order. It is not uncommon to need 2 or more sizes on any driveway or walkway, so try samples all around the project. Push the sample into the slab. If it pulls out easily with your finger, go up sizes until you need a screwdriver to pull the sample out. You are looking for the tightest possible fit. SlabGasket cuts easily with sharp garden pruning shears, a sharp pocket knife, or a box cutter.


a. First clean out the expansion joint. You probably have a tool at home to do this. People have used small crow bars, long screwdrivers, wood chisels, etc.

b. You may encounter the occasional nail when cleaning out the expansion joint. These were used when the slab was framed to nail the framing board to the stake. Be careful when removing these items. Wear safety eyewear! It is suggested that you use a hacksaw blade or inexpensive diamond masonry blade mounted on your circle saw or angle grinder to cut these nails. Otherwise, the nail may be strong enough to break your concrete if you attempt to pry it without cutting it.

c. Small chunks of concrete are easily chipped out with a hammer and chisel. Again, wear protective eye wear! You may also use a diamond masonry blade on your circle saw or angle grinder to cut nails and smooth or widen the concrete.

a. The expansion joint should be backfilled with sand or very fine gravel to build up a base to the point where the bottom of SlabGasket will lay. Larger gravel can be used with the larger widths.

b. Roll the length of SlabGasket loosely along the expansion joint. Be careful not to drag SlabGasket across the concrete surface on its top, it will get scratched. As you install SlabGasket, push the material into itself to compress it as much as possible. This compression process will mitigate any shrinkage inherent with vinyl products. We ship you a little extra to allow for this. Avoid stretching SlabGasket! Later, when the slab cools, it could “rubber band” back on itself.

c. Trim or “V” notch the bottom or side of SlabGasket with your pocket knife, box cutter or garden pruning shears in order to pass over or around obstacles which prove to be too difficult to remove.

d. Try to avoid inline splicing. SlabGasket comes in 50 foot rolls and sells by the foot. Figure the lengths you need and order accordingly. If you need to join two pieces of SlabGasket to finish an area, cut each of the two pieces an inch or so long, leaving two feet or so of each out of the joint temporarily. Then put the ends together, and wiggle and compress the rest into the joints. Now you have a good, snug fitting joint.

e. Use the same method as d. above to do a butt joint. Leave a couple of feet out at the end where you are going to butt the material into the material in the next joint, cut the material an inch or so longer than the joint, put the end in first and wiggle and compress the material into the joint.

f. Where SlabGasket crosses at an intersection, cut a square notch out of the top of one piece and the bottom of the other piece, lock the two pieces together and press this assembly into the joint. Then you have a secure joint and the material won’t come apart. The bottom piece notch should be a little narrower than the material size for a snug fit.

g. We use a dead blow hammer with a non marking face to install SlabGasket. If you don’t have one of these, step the material in as far as you can, then use a wood 1×2 and a regular hammer or small sledge hammer and tap the SlabGasket at or a little below the surface.


a. Wait until after the installation is complete to wash or pressure wash your driveway, patio or walkways. There is no need to create a mess before you start.

b. SlabGasket requires no curing or waiting. Walk or drive on SlabGasket immediately.