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Caulk Siding

How to caulk siding

Have you ever found yourself staring at a wall, thinking, “Boy, this wall would look so much better if all of those joints were caulked”? Probably not, but now that you’re looking, here’s how to caulk siding and get that work done.

What You’ll Need

Big Stretch®

100% acrylic elastomeric caulk

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Water-based acrylic latex textured wood caulk

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eXact color®

eXact color® is the easiest and fastest way to create custom-colored caulk with no tools required

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Lexel® synthetic rubber elastomeric sealant is the superior alternative to silicone caulk in clarity, adhesion, elasticity and paintability.

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  1. Gather tools

    You’ll need:

    • One of the products listed above
    • Sashco Filler Rope™ or other backer rod
    • Utility knife to remove old caulk and open the caulk cartridge
    • Caulk gun
    • Painter’s tape (optional)
    • A beading tool, trowels or foam brushes for tooling
    • Damp rags or mineral spirits for clean-up
    • Sweet shades to protect your eyes from the overwhelming glare of wicked awesome work
  2. Clean the joints

    If you want your caulking job to stick and stretch for years to come, make sure you clean the surfaces and remove old caulk. Wipe off any dust, fingerprints, oil spots, etc. If silicone is present, use a silicone caulk remover.

  3. Apply the caulk

    If you want your caulking job to stick and stretch for years to come, make sure you clean out old caulk, dirt, flaking paint, damaged wood fibers, and other contaminants.

  4. Insert Filler Rope™

    Any crack that’s deeper than ½” and wider than ¼” needs Sashco’s Filler Rope™ or some other type of backer rod so the caulking will properly stretch, and so you use less caulking.

  5. Apply the caulk

    Be smooth about it now. A steady hand will save you clean up later and contribute to that wicked awesome glare we talked about above.

  6. Tool (smooth) the caulk

    Use a damp foam brush, a trowel, a beading tool, or your trusty fingers to create a good-lookin’ bead and ensure the caulk is sticking to the sides of the joint properly. For an even neater bead, line the joints with blue painter’s tape. Remove after tooling but before the caulk dries.


  7. Clean up

    Use soap and water* or mineral spirits** to clean up skin and tools. Stand back and admire your handy work.

    *for Big Stretch, Conceal and eXact color
    ** for Lexel

Special Tip

It might make things look super neat, but never caulk the bottom edge of siding. Those small openings are there to help moisture escape, which prevents mold, mildew, rot, peeling paint, and frustration. (Yes, that means that learning how to caulk siding can be an exercise in restraint.)