It needs to move and breathe.
Caulking lap siding.
When to use caulk on exterior siding siding caulk can be used on several different areas of your exterior siding to help prevent water damage and moisture buildup.
Slide a piece of metal sheeting behind the butt joint.
Some of the most commonly caulked areas of siding include both corners and crevices as well as some butt joints and window and door trim boards.
Bottom of siding boards should not be caulked water is meant to exit through the bottom of each board.
Caulking around windows doors eaves and trim edges gives added insurance that leaks will not occur.
Think of a wood home as a living thing.
While paint does tend to somewhat glue these pieces together caulking them is never advised and can cause permanent damage.
Caulking at the horizontal overlaps is not recommended because it impedes these drainage and drying mechanisms inherent to lap siding.
How to caulk the window trim on lap siding 1.
Caulk is by necessity a sticky gooey substance and as such it smudges easily.
And many homeowners over caulk applying caulk where it doesn t belong and potentially compromising the performance of their siding.
The fundamental principle of water management is to shed water by layering materials in such a way that water is directed downwards and outwards out of the building or away from the building.
Caulking them is a mistake and the caulking is likely to fail prematurely.
The siding expands and contracts with temperature and humidity.
Pull the tip of the caulk tube slowly along the joint of the window trim and the siding holding the caulk gun at a.
Caulking your home s siding is a simple process but not necessarily a foolproof one.
Use a keyhole or reciprocating saw with a fine tooth blade to remove enough material from one of the pieces of lap siding.
In my opinion caulking between the seams in any lapped siding either horizontal or vertical is not good practice but not just because of any potential vapor barrier effect.