Joint sealing is the application of caulk or sealant to gaps, cracks, and expansion joints in concrete to keep water from seeping underneath and washing out the supporting soil.
In depth
Water reaching the soil beneath a slab is the root of most settlement, and joints and gaps are its easiest entry point. Sealing them closes that pathway, so surface water runs off instead of soaking in and eroding the base. It is a low-cost, high-value maintenance step, especially after a slab has been raised.
Joint sealing works hand in hand with good drainage: redirecting downspouts and grading water away from the slab handles the volume, while sealing handles the seams. Together they keep the stabilized subgrade dry and intact.
How Acme applies it. Acme advises maintaining structural integrity by filling voids with polyurethane and applying caulk to gaps and expansion joints to prevent water seepage under the slab, helping prevent future sinking.
Related terms: Expansion Joint, Soil Washout, Grading & Drainage, Concrete Cracking
Frequently asked questions
Why is joint sealing important after concrete leveling?
It keeps surface water from seeping through the joints into the newly stabilized soil, which prevents the washout that causes slabs to settle again.
How often should joints be resealed?
Sealant wears with weather and use, so joints should be checked periodically and resealed when the caulk cracks, shrinks, or pulls away from the concrete.