Caulking Cement Fiber Siding

Both certainteed and jameshardie as of september 2008 have made clear that siding butt joint gaps should never be made that is.

Caulking cement fiber siding.

Best caulk for fiber cement siding or hardiplank siding lets you have the perfect sealing your surface needs. What you want to use is a silicone caulk because it s the most permanent one. 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. Flashing acts as a waterproofing layer for this type of siding and caulking will prevent the flashing from doing its job.

Caulk is usually used with fiber cement siding to prevent water intrusion at the butt joints. Fiber cement boards are caulked only when there is no metal flashing behind them. However this detail may not be effective at sealing the ends allowing water to be absorbed and swell the board ends. So what i would tell you to do is to use a colored caulk to choose the caulk in the color of the siding.

Natural siding boards are designed to expand and contract with the elements and we do not want any adhesive to prevent their natural movement. Caulking around windows doors eaves and trim edges gives added insurance that leaks will not occur. That is why we are showing you some other products for various surfaces along with our top pick. It s got good adhesion and expands and contracts.

But you are correct that it is very difficult to paint. Big stretch acrylic latex caulking sealant by sashco. Siding butt joint treatment. Do not deliberately leave butt joint gaps in fiber cement lap siding and that they do not recommend caulking field cut butt joints in their board type fiber cement siding products.