Caulking Fiber Cement Siding

1 i chose this caulk because it has 25 flexibility compared to silicone based caulk.

Caulking fiber cement siding.

Butt joints however should be nailed tightly together and should not be caulked. 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. 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. 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.

Do not caulk fiber cement siding butt joints edges. Some manufacturers do not require the metal flashing therefore we caulk the butt joint to keep the pieces together and also prevent moisture. We only caulk butt joints on cedar siding if previously caulked. Sealing caulking fiber cement siding.

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. It is never acceptable to leave a gap of any size at a butt end joint. Trim boards wood windows.

2 house built before 2008 so has no flashing okay to caulk. Caulking around windows doors eaves and trim edges gives added insurance that leaks will not occur. Flashing acts as a waterproofing layer for this type of siding and caulking will prevent the flashing from doing its job. Butt end joints should be installed with factory sealed or factory prefinished ends butted together in moderate contact.

That is why we are showing you some other products for various surfaces along with our top pick. Cut ends of fiber cement siding should have been sealed using 100 acrylic latex primer or paint certainteed or in some cases using an approved caulk wiped on the cut surface see our notes on hardieplank installation. However this detail may not be effective at sealing the ends allowing water to be absorbed and swell the board ends. Best caulk for fiber cement siding or hardiplank siding lets you have the perfect sealing your surface needs.