Caulking Lap Siding Bottom Edge

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 lap siding bottom edge. One way to prolong the useful life of the siding is to keep it well maintained. It needs to move and breathe. For the same reason do not caulk exposed nail heads. Garage door panels should not be caulked.

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. Window weep hole should not be caulked. 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. Refer to the colorplus touch up section for details do not use caulk on hardieplank lap siding with colorplus technology.

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

The worst failure we have seen yet. The panel siding tends to do better than the lap siding because there is no drip edge for water to cling to. The corner boards and the ends of the siding are nailed to the corner studs which anchors the wood for a maintenance free joint. All penetrations such as over driven fasteners and site cut edges of siding need to be sealed with caulk and paint.

While a diyer or a novice painter might attempt to produce a cleaner look by. Trim boards that sit on top the siding.