Caulking Between Wood Siding

Fill in gaps between crown moulding and baseboards.

Caulking between wood siding.

The siding expands and contracts with temperature and humidity. While paint does tend to somewhat glue these pieces together caulking them is never advised and can cause permanent damage. Matt is 100 correct. Most other areas were caulk is necessary should be lightly smoothed with your finger.

The hole should be about 3 16 of an inch for most caulking joints. Caulking them is a mistake and the caulking is likely to fail prematurely. 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. You never ever caulk the underside of lap siding.

Seal a door frame in place and seal the subfloor at the bottom of a door frame. In my opinion caulking between the seams in any lapped siding either horizontal or vertical is not good practice but not just because of any potential vapor barrier effect. Think of a wood home as a living thing. 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.

It needs to move and breathe. Caulking on the exterior siding joints at the corner board if done carefully does not need to be smoothed with a finger. Best for use with drywall wood and masonry. Bottom of siding boards should not be caulked water is meant to exit through the bottom of each board.

Flashing acts as a waterproofing layer for this type of siding and caulking will prevent the flashing from doing its job. Use latex painter s caulk inside of doors and windows or to quickly fill cracks.