Concrete Surfaces Crack Repair
Concrete is hard to beat for its strength durability and longevity, but to perform reliably it needs to be structurally sound. One of the most common problems when it comes to concrete is cracking. When water penetrates a crack it can cause structural issues and shorten the life of the concrete. If concrete has deep cracks or a significant surface damage you’ll need to repair those areas before top coating or resurfacing.
The repair method used depends on the type of crack. If the crack is a static crack for one that isn’t moving a high-quality polyurethane is recommended. A polyuria is semi-rigid and self levelling which is ideal for repairing and stabilizing horizontal cracks. It’s high solids formula is durable enough to support heavy wheel traffic with good wear resistance and the strength to reduce further stress cracking. Crack bond jf 311 is perfect for repairing static cracks. This self levelling low viscosity system protects joint edges from spalling treated joints can be open to traffic in as little as 90 minutes and it’s available in BOC compliant formulations.
Some cracks are dynamic or always moving due to temperature changes over time and require a polyurethane sealant. Polyurethane sealants typically have greater elongation properties than polyuria ‘z allowing them to expand or contract as the temperature fluctuates. Locks on 1sl polyurethane sealant is ideal for restoring dynamic cracks. This elastomeric polyurethane cures to a flexible rubber like consistency. It adheres well to a wide variety of substrates and can accommodate up to 70% joint movement, it’s also BOC compliant nationwide and can be painted after it’s fully cured.
the crack is less than 1/32 to 1/4 inch wide there are two ways to repair it using the following tools. A caulk gun, sealant, four inch scraper and a backer rod or silica sand. Before getting started make sure the surface is clean dull dry and sound. Consult your local Sherwin Williams store or sales rep for surface preparation recommendations or refer to the surface prep video in this series. The first option is to slightly overfill the crack with a sealant. Allow it to cure for about an hour then shave off the excess with a four inch scraper so it’s flush with the surface. Application of the sealant should not exceed 1/2 inch in depth depending on the width and depth of the crack, it may be appropriate to use a backer rod or silica sand as a filler leaving half inch depth for the sealant.
If you’re planning to coat the surface or apply a broom finish after the repair it’s better to under fill the crack. While the sealant is still wet broadcast silica sand over the surface to give the repaired area some texture and enhance bonding to the finish coat. Allow the sealant to dry completely and blow off any excess sand before top coating. If the crack is greater than a quarter to half inch wide you’ll repair it in a slightly different way using a caulk gun the proper sealant a dustless angle grinder or crack chasing saw with a U or V shaped diamond blade and a dry tool.
Start by routing and cleaning the crack with a chaise saw blow out any loose particles then apply the sealant. If you’re not using a self-leveling sealant you may need to tool the sealant to properly fill a wider horizontal crack. Now the repaired concrete surface can be top coated with a variety of Sherwin-Williams stain sealers and coatings, to not only protect but beautify the concrete surface. With the right information and a few basic tools you can repair most cracks and give aging concrete of fresh appearance that’s safe attractive and stands the test of time.