Caulking is the least visible part of a building envelope and one of the most consequential. A joint is a few inches of sealant that nobody looks at, and when it fails the symptom almost always appears somewhere else entirely.
That is what makes it hard to diagnose. The problem you notice and the problem you have are in different places.
What a joint is holding back
Caulking seals joints and cracks against the intrusion of water, air, dust, insects and noise. Five separate problems, one detail.
Water, which travels
Water entering a failed joint does not stay there. It tracks inside the wall, following whatever path the construction gives it, and emerges as a stain on an interior finish that may be some distance from the entry point. By the time it is visible, it has been wet inside the wall for a while.
The more expensive version is what it does on the way: corroding fixings, saturating insulation, and in freeze-thaw climates, expanding inside the joint and opening it further every winter.
Air, which costs money continuously
Air infiltration through failed joints is a steady, invisible load on heating and cooling. Nobody notices it happening, because there is no single moment when the bill jumps. In a large building with a lot of joint length, it adds up to a running cost that never appears as a maintenance item.
It also shows up as comfort complaints near exterior walls, which get attributed to the HVAC system.
Dust and insects, which matter more in some buildings
In a food plant, a packaging facility or anywhere with a clean requirement, a failed exterior joint is a pest and contamination route. That is an audit issue as much as a maintenance one, and it is the kind of finding that is hard to argue with because the evidence is visible.
Noise
Less critical, but worth naming. Joints are part of what keeps external noise out of office and support areas.
How to walk a building and spot it
You do not need to be a specialist to find the obvious failures. Look for:
- Sealant that has pulled away from one side of a joint
- Cracking or crazing along the length of a bead
- Sealant that has gone hard and lost its flexibility
- Gaps at joint intersections and corners, which move most
- Staining on the wall below a joint, which indicates water is already tracking
Check control joints, stone-to-stone joints, precast connections and concrete joints, and pay particular attention to anywhere two different materials meet.
What to do first
Deal with anything letting water in before anything else, and settle it before you schedule exterior painting, since a coating over a failed joint hides the problem without fixing it.
When a joint is recaulked, complete removal of the existing sealant is critical, including any residual film along the joint edges. Caulking over remnants of the old material is the most common cause of failure in recaulking work.
Read about our caulking and sealant services and exterior painting, or send us photos of a joint.
