Caulk is a go-to sealant for gaps, holes, cracks, and crevices. Siding caulk is formulated to seal vinyl and wood siding. You can apply it anywhere it’s needed, but you’ll use it most commonly on windows, door trim boards, butt joints, and crevices. A properly sealed exterior improves your home’s energy efficiency and prevents water damage.
Keep reading to learn more about how to caulk siding, from choosing the right product to applying it correctly.
Different Caulk Formulas
You can find six siding-friendly caulk formulas on the market today. Each has distinct traits and purposes:Â
This option, sometimes called painter’s caulk, is the most widely known and used. It’s affordable, dries quickly, and you can use it for nearly any type of application. It’s especially suited to sealing wooden parts and repairing dented wood trim.
You may see latex with silicone caulk described as tub and tile caulk, since it’s mostly used in bathrooms and kitchens, but you can use it for a variety of purposes. It’s more durable, flexible, and moisture-resistant than acrylic latex caulk.
Masonry repair caulk comes in handy to correct and patch up cracks on stucco walls. It also works for joint expansion for concrete surfaces like driveways.
Pure silicone costs more than other caulks, but it’s waterproof, making it a good choice for plumbing fixtures. A downside of this caulk is that you can’t paint over it.
Butyl rubber is a sticky formula used for metal and masonry. It’s particularly useful to seal gutters, and, unlike pure silicone caulk, you can paint over it once it’s cured.
Refractory caulk is sometimes called high-temperature sealant. It comes in handy to fill small cracks in fireplaces and chimneys, bricks, and concrete, but you can only use it for small repairs.
How To Choose the Right Caulk for Your Siding
Choosing the right caulk for your type of siding can be tricky. You’ll need to weigh a few factors, but the two below are the most important.
Each caulking material has distinct properties and different intended purposes. Acrylic latex and silicone caulks work well with vinyl siding, while wood siding may need a more flexible sealant.
Take into account the environmental conditions where you live. If you’re in a wet part of the country, moisture resistance is key for a good seal, and you may want to think about pure silicone caulk for your siding. Otherwise, latex with some added silicone will work.
Try to find caulk that resembles your siding’s color. This was a tall order in the past, but manufacturers now make caulk in a variety of shades.
If you can’t find an exact match, choose a caulk slightly lighter than your siding color—that way, it won’t be as easy to notice.
Preparing To Caulk Your Siding
Before you grab your caulking gun, follow some preliminary steps for the best seal:
- Clean the siding: Thoroughly clean the areas you’re caulking with a damp cloth. You can use a mild detergent for stubborn spots.
- Remove any old caulk: Old caulk becomes brittle and loses its effectiveness with time. If there’s existing caulk you need to replace, remove it before you apply a new bead of sealant. You can do this with a putty knife or specialized removal tool. Silicone-based products may also require a chemical caulk remover to soften the seal.
- Dry the surface: Moisture can prevent proper adhesion and lead to a failed seal. Dry surfaces completely before you apply new caulk.
Applying New Caulk
Once your siding is clean, stripped of old caulk, and dry, you can apply a new bead.Â
Some caulking guns have a built-in feature to help you cut open caulking tubes. If you have a more basic model, cut the tip of the caulk tube at a 45-degree angle and so that the size of the opening is the same width as the gap you’re filling. Start with a small opening—it’s easier to make it larger than deal with wasted caulk.
Load the tube into the caulking gun and squeeze the trigger a few times to prime it. Hold the gun at a 45-degree angle to the joint, and apply steady pressure while you trace the new caulk along the joint. For best results, push the caulk into the gap rather than dragging it.
Finally, smooth the caulk for a professional-looking finish. Depending on the type of caulk you’re applying, you can use a caulk smoothing tool, a wet finger, or a plastic spoon to make a concave surface that sheds water effectively. Remove any excess caulk immediately with a damp cloth.
Let the new caulk cure according to the package instructions. Don’t paint it or expose it to water until the curing process is complete.
