Photos: Eric Crichton
To close up the big gap opening up behind this stone veneer, Tom Silva recommends applying a high-quality exterior caulk over a foam backing rod.
Q: There's a 3/8-inch gap between the stone veneer on the front of my house and the stuccoed side wall. The gap does not seem to be getting wider. Should I fill it?

—Alton Dorazio, Longwood, FLA.

A: Tom Silva replies: I think it would be best—both for appearance' sake and to keep out bugs and water—if you bridged the gap with a high-¬≠quality exterior sealant. But if the gap is more than ½ inch deep, you should not just fill it with caulk. Your work will last longer and perform better if you first put in a flexible foam backer rod.

Choose a rod diameter that fits snugly in the gap, then push the foam just below the surface of the stucco with something blunt like a paint stir stick so you don't puncture it. Once the rod is in place, cover it with a UV-­resistant, paintable acrylic caulk or a tripolymer sealant like Geocel, then smooth the joint. You might even be able to find a caulk or sealant that comes in a color that matches your house.

After you make this fix, keep an eye on it. If the caulk breaks loose from either the block or the veneer, you may have to reattach the stone to the wall.
Ask TOH users about Siding

Contribute to This Story Below