Caulking Fiber Cement Siding

Fiber cement boards are caulked only when there is no metal flashing behind them.

Caulking fiber cement siding.

Big stretch acrylic latex caulking sealant by sashco. 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. Flashing acts as a. Natural siding boards are designed to expand and contract with the elements and we do not want any adhesive to prevent their natural movement.

That is why we are showing you some other products for various surfaces along with our top pick. They re cheaper and easy to install and you can cut the proper size hole in a plastic mounting block with a utility knife or a snips. In my experience water that gets trapped against fiber cement siding can be absorbed by the material causing joints to swell and shrink during freeze thaw cycles. Item 157140 model 11532.

Most fiber cement manufacturers make mounting blocks for lights electrical receptacles a c lines pvc venting etc. Instead we snug the joints up tight and. 1 i chose this caulk because it has 25 flexibility compared to silicone based caulk. Jaime prefers to use the vinyl mounting blocks typically used with vinyl siding.

The following information is adapted expanded a bit from certainteed corporations installation instructions for the company s fiber cement siding products as this is the most comprehensive guide we could find for caulking clearance instructions when installing fiber cement siding. On our jobs we typically don t leave gaps for caulk at butt joints because this detail can contribute to the problem. 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. Best caulk for fiber cement siding or hardiplank siding lets you have the perfect sealing your surface needs.

Dap alex plus 12 pack 10 1 oz white paintable latex caulk. Caulking around windows doors eaves and trim edges gives added insurance that leaks will not occur. 2 house built before 2008 so has no flashing okay to caulk.