Outdoor Caulking Projects
Caulking is a cornerstone of outdoor painting. Caulk’s main job is to fill in the spaces that would otherwise let cold air, insects, rats, and water into your house. The last of these, water, is a particularly dangerous and persistent foe. It can undermine exterior paint, causing one or more of several ill effects: chalking, cracking, peeling, and bubbling. Accumulated dampness may breed fungus, which in turn can endanger the residents. Thinking defensively means plugging the passageways these threats could travel through with well-made caulk.
What Products to Use
When it comes to sealants, elastomeric caulk is the crème de la crème. It’s malleable, holds firmly, and has staying power. For all its strength, however, it’s still conveniently water washable. It’s also essential to select a caulking gun that suits your project.
Where to Apply Your Sealant
Caulking isn’t something to be done halfway. A house that is completely insulated and sealed is a safer, less expensive one. Wherever two different substances come into contact — a brick chimney and metal siding, for example — caulking might be useful.
Working with Caulk Around Windows
The bottom of a window’s trim is the only part that should remain uncaulked. Moisture that travels down the windowpane might otherwise find its way into the house. Another reason to omit caulk from the trim’s lower edge is to avoid trapping condensation inside the building. Obviously, a home’s weep holes — gaps in the masonry that allow water to escape — should not be sealed, either.
If a window doesn’t have trim, you should apply caulk on all sides. Guide your work by adding tape an eight of an inch from where the glass meets the surrounding wall, around the window’s circumference, and then caulking in between. The more caulking skill you develop, the less you’ll have to rely on the tape. Keep in mind that even transparent caulk, like the elastomeric variety, appears white at first. The drying process changes it from white to clear.
Windows whose frames are made of wood tend to need more caulk. Where two segments of wood meet, sealing is necessary. Parts of a wood window that merit special attention include the uppermost trim, the places where the trim and the siding and sill come together, the entire area surrounding the sill, and the places where glass and wood unite. Moisture can get through these junction points and make paint peel (and wood break down). If the caulk you’re using is paintable, applying a small amount and spreading it evenly should suffice. The benefit of transparent sealant is that it can be used even after you’ve painted the sash.
Every door is a caulking hotspot. Areas where frame and threshold are flush, and where trim and frame (or siding) meet, demand protection against invasive moisture.
Doorframes in garages have a tendency to absorb dampness from the concrete floor, which leads to paint damage and decaying wood. Caulk can stop this problem before it starts. If your garage’s doors are paneled — whether they’re made of wood, Masonite, or another material — they should be sealed after you’ve sanded and primed them.
How to Seal Soffits and Fascia Boards
Soffits (the undersides of a roof’s overhangs) and fascia boards may be out of sight, but they shouldn’t be out of mind. If you apply caulk behind the boards, both fascias and soffits will last longer.
Guidelines for Caulking Brick and Concrete
When working with brick or concrete, it’s especially important to use transparent caulk. The alternative, after all, is hardly aesthetically pleasing. (Spaces in concrete can be filled with concrete caulking, which is gray and may be made of urethane or siliconized acrylic.) Even though substances like brick and stone appear waterproof, they inevitably connect with another material that is not. It goes without saying that those junctions must be sealed.
Portions of a house’s exterior that have not previously been sealed can be painted before they’re caulked. With these areas, the goal is to make the paint look as good as possible before worrying about the sealing process.