Caulking Cedar Lap Siding

If overused or incorrectly placed siding caulk can cause more damage to your exterior than good.

Caulking cedar lap siding.

Corner boards are applied to the sheathing with siding fitting tightly against the narrow edge of the boards allowing for expansion and an adequate caulking bead. If i am installing a prefinished product which i do mostly i use a color osi match caulk. If i install a non finished product i usually go with a 3m paintable caulk. Whether you are repainting replacing a window or replacing the siding on your house the caulking around the window trim is a very important element.

How to caulk the window trim on lap siding. The siding expands and contracts with temperature and humidity. Caulk by its adhesive nature will try to limit this movement leading to widespread failure and cracking in the caulk over time. Natural siding boards are designed to expand and contract with the elements and we do not want any adhesive to prevent their natural movement.

When deciding how to use caulk on your siding however it is generally more important to consider where you should not use it. Generally we do not recommend caulking butt joints on cedar siding. The answer depends on the manufacturer and installation method used when the siding was first installed. The corner boards and the ends of the siding are nailed to the corner studs which anchors the wood for a maintenance free joint.

When you try to restrict either it is at your peril. It is generally not a good idea to use caulking on wood siding. Width is a matter of taste and proper proportion.