Siding is most vulnerable to water infiltration at vertical joints, such as where doors and windows intersect, or where siding boards butt against one another. Tube caulking is easy to apply, and it’s available in colors to match natural or painted finishes.

Choose a quality caulk that will maintain its elasticity over a range of temperatures. Cut the tube’s tip at a slight angle, and push it into the joint as you apply the caulk.