Cracks or expansion joints look unsightly and they trap dirt and spills making it difficult to maintain the floor and keep it looking sharp and clean. If the cracks are large enough they also make it difficult to move carts, tool chests, jack stands and other items. Fortunately there are products available which are able to fill those spaces and leave you with a smooth and durable floor. For high performance crack putty we recommend Wolverine Coatings IntegraFlex 1921 Flexible Joint Sealant.

For a small crack it’s fine to just fill it with IntegraFlex 1921, however with larger concrete cracks or joints you should take the time to first form a “v-notch” in the crack – this is known as “chasing the crack.” Here’s why chasing the crack is important…

After a crack or expansion cut is filled with putty, as the concrete expands or shifts it can compress the putty and squeeze it up and out of the crack. If too much putty is forced up - it may cause the epoxy coating to split on the surface.

Crack with IntegraFlex 1921 (green)and no v-notch	As putty is forced up the epoxy coating (red) may split

One way to help prevent this is to cut or grind a “v-notch” along the crack’s length before the putty filler is applied. The notch will spread out the pressure and help minimize the chance of the epoxy coating splitting.

V-notch is cut first, and then IntegraFlex 1921 is applied, followed by the other coatings.	The force on the IntegraFlex 1921 is spread out, minimizing pressure on coatings.

There are several tools available to chase the crack. Probably the most common DIY method is to use a hand held angle grinder. There are blades made specifically for cutting the v notch, but they can be hard to find. A wide grinding blade or diamond cup wheel at an angle will also do the job, check with your local tool shop for recommendations.

Note that the larger the crack, and the more putty used, the greater the potential displacement and problems. So if the floor has a deep “never ending crack” rather than completely filling it with putty you should first stuff some “backer rod” (available in hardware stores) in the crack and then apply the IntegraFlex 1921 putty. The backer rod should be about 1.25x larger than the crack, it will compress when it’s inserted.

IntegraFlex 1921 is a 100% solids, two-component polymer hybrid resilient filler for expansion joints and cracks in concrete or masonry. When cured IntegraFlex 1921 is extremely durable yet retains excellent flexibility (up to 50% elongation at 70°f), it is self priming, and provides exceptional adhesion characteristics. IntegraFlex 1921 is recommended for expansion joints in general industry as well as expansion joints of garages, highways, bridges, driveways, sidewalks, and marine decks. For vertical or overhead joints and cracks we offer IntegraFlex 1922. Both IntegraFlex 1921 & 1922 provide an excellent bonding surface for other Wolverine Coatings Corporation products like BondTite 1101. A one gallon kit will fill approximately 165 cubic inches.