Caulking Lap Siding Bottom Edge

While a diyer or a novice painter might attempt to produce a cleaner look by.

Caulking lap siding bottom edge.

Wherever hardie siding meets a trim board the company recommends you leave a 1 8 gap between the siding and the trim and apply a 3 8 bead of approved caulking to protect and seal the edge of the siding. Trim boards that sit on top the siding. Designed to let water out of your windows these small openings should never be. Caulk across the top edge of the siding where it meets the top of the wall around windows and doors across the bottom edge of the siding where it meets the foundation and any other area where gaps exist.

Corner boards are applied to the sheathing with siding fitting tightly against the narrow edge of the boards allowing for expansion and an adequate caulking bead. It needs to move and breathe. The corner boards and the ends of the siding are nailed to the corner studs which anchors the wood for a maintenance free joint. 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.

Caulking at hardieplank lap siding butt joints is not recommended for colorplus for aesthetic reasons as the caulking and colorplus will weather differently. Refer to the colorplus touch up section for details do not use caulk on hardieplank lap siding with colorplus technology. The panel siding tends to do better than the lap siding because there is no drip edge for water to cling to. All penetrations such as over driven fasteners and site cut edges of siding need to be sealed with caulk and paint.

Lp siding products also come in sheets in when water runs down the face of the siding it tends to hang on the bottom edge wicking up and causing the bottom edges to swell and delaminate. The siding expands and contracts with temperature and humidity. Window weep hole should not be caulked. Garage door panels should not be caulked.

Think of a wood home as a living thing. The bottom edge of lp lap siding is where the failure is first evident.