Flashing Behind Hardie Board Siding

Failed caulk joint with no flashing behind.

Flashing behind hardie board siding.

Hardiplank lap siding field butt joint treatment. Coating paint means no reflective flashback as found using regular metal flashing. During the course of any siding installation it will be necessary to install two pieces of siding against each other in a course. This is a 6 wide piece of weather resistive material to make sure that no water gets through.

Use to reduce moisture penetration behind the joint where two planks butt together and drain water over the top edge of the last full course of siding. Remember one of the main hardie siding problems is water damage however it s also one of the easiest to prevent with proper installation. The caulk has failed and water can find its way behind the siding. This is a butt joint and it.

Most contractors will remember to do this but some of them try to save a buck by cutting squares of building paper for. The product is a proprietary plastic 20 year uv rated sheet 4 ml thick that is basically a six by twelve post it note. In this first picture we see what a typical siding joint looks like on a home that was sided with cement board siding and there is no flashing behind the butt joints. James hardie also does not recommend applying caulk to the horizontal overlap between siding planks see figure 2.

James hardie recommends 6 inch wide flashing that overlaps the course below by 1 inch. Hardiplank lap siding is a fiber cement siding product that looks like wood clapboards but outperforms it when it comes to weather resistance and finish performance. James hardie recommends that a slip sheet joint flashing is installed behind each butt joint in the siding. Flashing behind butt joints is an effective low maintenance way to comply with building code and help protect against water intrusion.

Water which makes it s way behind the hardie siding should hit the flashing layer. The flashing keeps water off the sheathing and drains water properly which prevents water damage. Coating eliminates any reaction with fiber cement. Joint flashing butt joint horizontal lap treatment june 2014 james hardie does not recommend caulking butt joints or the horizontal overlaps joint flashing 6 in.

Each sheet is pre cut with a stick it adhesive for the fastest application available. Pre cut for quick and easy installation. Hardiplank lap siding is a fantastic siding material that we ve been using for years on both residential and light commercial building projects.