Caulking Lap Siding

How to caulk the window trim on lap siding.

Caulking lap siding.

When deciding how to use caulk on your siding however it is generally more important to consider where you should not use it. Similar to paint previous coats of. Caulk by its adhesive nature will try to limit this movement leading to widespread failure and cracking in the caulk over time. 25 4 mm on overlap no caulk figure 1.

And many homeowners over caulk applying caulk where it doesn t belong and potentially compromising the performance of their siding. When james hardie siding products butt into wood based materials a 1 8 gap will allow for expansion and contraction of the wood based product. In this instructional video we demonstrate how to use proper caulk techniques on lp smartside products pre finished with diamond kote which recommends dap. The nails holding up the siding should not be caulked.

James hardie also does not recommend applying caulk to the horizontal overlap between siding planks see figure 2. The siding expands and contracts with temperature and humidity. It is generally not a good idea to use caulking on wood siding. When you try to restrict either it is at your peril.

Caulk is by necessity a sticky gooey substance and as such it smudges easily. It needs to move and breathe. Caulking around windows doors eaves and trim edges gives added insurance that leaks will not occur. 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.

A diyer or a novice painter might attempt to achieve a cleaner look by caulking the siding nails but the nail is guaranteed to push the caulking material out within a few months. Caulking your home s siding is a simple process but not necessarily a foolproof one. Think of a wood home as a living thing. If overused or incorrectly placed siding caulk can cause more damage to your exterior than good.