Caulk does not last forever. Sun, heat, cold and the constant small movement of a house wear it out, and once it cracks or pulls away, it becomes an open door for water and drafts. In Northern Colorado, where the sun is strong and winters bring repeated freezing and thawing, that happens faster than many homeowners expect.
Fall is the right time to check. The weather is usually dry and still warm enough for sealants to cure properly, and any gap you close now is a gap that will not let water in and freeze through the winter.
Start with windows and doors. Look where the frame meets the wall — stucco, stone or siding — and along the top and sides. Then check the corners where different materials meet, the joints around trim, and anywhere pipes, vents, lights or wires come through the wall.
Failed caulk is usually easy to spot. It may be cracked, hard and brittle, shrunk into the joint, or pulled away from one side so you can see a gap behind it. Missing caulk, where a joint was never sealed at all, is just as common.
The right repair is to cut the old caulk out, not to run a new bead over the top. New sealant does not bond well to old, failed caulk, and covering it just hides the gap. The joint should be cleaned and dry, deep gaps need a backing so the sealant is the right thickness, and the sealant should be one that suits the materials being joined and stays flexible.
There is one gap you should never seal: the weep openings at the bottom of stucco and stone walls. These are designed to let water that gets behind the finish drain out. Caulking them shut traps that water inside the wall, which causes exactly the damage caulk is supposed to prevent.
If you would like a second set of eyes on your house before winter, call M&S Stucco & Stone at (970) 581-4342. We can check the joints, replace failed caulk, and repair any stucco or stone damage we find along the way.