Caulking Cement Fiber Siding

Caulk is usually used with fiber cement siding to prevent water intrusion at the butt joints.

Caulking cement fiber siding.

Flashing acts as a waterproofing layer for this type of siding and caulking will prevent the flashing from doing its job. But you are correct that it is very difficult to paint. What you want to use is a silicone caulk because it s the most permanent one. Natural siding boards are designed to expand and contract with the elements and we do not want any adhesive to prevent their natural movement.

Best caulk for fiber cement siding or hardiplank siding lets you have the perfect sealing your surface needs. Butt joints however should be nailed tightly together and should not be caulked. 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. That is why we are showing you some other products for various surfaces along with our top pick.

So what i would tell you to do is to use a colored caulk to choose the caulk in the color of the siding. Caulking around windows doors eaves and trim edges gives added insurance that leaks will not occur. Fiber cement boards are caulked only when there is no metal flashing behind them. We provide a table of all fiber cement siding installation clearance or gap specifications caulking requirements storage or moisture requirements.

Fiber cement boards don t expand and contract much but leave a little room for expansion at the end joints and then fill the gap with caulk. Many professionals like those at james hardie also agree that you should not use caulk on fiber cement siding unless there is no metal flashing underneath. Placing caulk over large portions of wood siding prohibits the natural movement of the wooden panels and can cause extensive damage to the exterior of your home. It s got good adhesion and expands and contracts.