Caulking Cement Fiber 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.

Caulking cement fiber siding.

Caulk is usually used with fiber cement siding to prevent water intrusion at the butt joints. Caulking around windows doors eaves and trim edges gives added insurance that leaks will not occur. But you are correct that it is very difficult to paint. Best caulk for fiber cement siding or hardiplank siding lets you have the perfect sealing your surface needs.

That is why we are showing you some other products for various surfaces along with our top pick. Fiber cement boards are caulked only when there is no metal flashing behind them. 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. We only caulk butt joints on cedar siding if previously caulked.

It s got good adhesion and expands and contracts. Butt joints however should be nailed tightly together and should not be caulked. We provide a table of all fiber cement siding installation clearance or gap specifications caulking requirements storage or moisture requirements. Flashing acts as a waterproofing layer for this type of siding and caulking will prevent the flashing from doing its job.

Natural siding boards are designed to expand and contract with the elements and we do not want any adhesive to prevent their natural movement. So what i would tell you to do is to use a colored caulk to choose the caulk in the color of the siding. What you want to use is a silicone caulk because it s the most permanent one. 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.