Caulking Fiber Cement Siding

Big stretch acrylic latex caulking sealant by sashco.

Caulking fiber cement siding.

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. 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. Item 157140 model 11532. Jaime prefers to use the vinyl mounting blocks typically used with vinyl siding.

Fiber cement boards are caulked only when there is no metal flashing behind them. That is why we are showing you some other products for various surfaces along with our top pick. Most fiber cement manufacturers make mounting blocks for lights electrical receptacles a c lines pvc venting etc. 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.

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. Caulking around windows doors eaves and trim edges gives added insurance that leaks will not occur. 1 i chose this caulk because it has 25 flexibility compared to silicone based caulk. Natural siding boards are designed to expand and contract with the elements and we do not want any adhesive to prevent their natural movement.

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. A mark parlee a general contractor in des moines iowa responds. Dap alex plus 12 pack 10 1 oz white paintable latex caulk. Best caulk for fiber cement siding or hardiplank siding lets you have the perfect sealing your surface needs.

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. We only caulk butt joints on cedar siding if previously caulked. Flashing acts as a.