Caulking Lap Siding

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

Caulking lap siding.

Joint flashing butt joint horizontal lap treatment june 2014 james hardie does not recommend caulking butt joints or the horizontal overlaps joint flashing 6 in. It is generally not a good idea to use caulking on wood siding. It needs to move and breathe. 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.

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. Caulking your home s siding is a simple process but not necessarily a foolproof one. Do not caulk fiber cement butt joints edges. Lp smartside strand substrate primed lap siding application instructions pdf op cit.

Is the old caulking removed before new coats are applied. 152 4 mm wide 1 in. The nails holding up the siding should not be caulked. The specification to omit caulk at siding butt joints is for new installations and is discussed in detail by the manufacturer.

Caulking around windows doors eaves and trim edges gives added insurance that leaks will not occur. Caulk by its adhesive nature will try to limit this movement leading to widespread failure and cracking in the caulk over time. When you try to restrict either it is at your peril. In this instructional video we demonstrate how to use proper caulk techniques on lp smartside products pre finished with diamond kote which recommends dap.

Lp smartside cedar shake primed lap siding application instructions pdf op cit. 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. How to caulk the window trim on lap siding.

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. Similar to paint previous coats of. 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.