Caulking Hardie Lap Siding

152 4 mm wide 1 in.

Caulking hardie lap siding.

Caulking around windows doors eaves and trim edges gives added insurance that leaks will not occur. Caulking around windows doors eaves and trim edges gives added insurance that leaks will not occur. When james hardie siding products butt into wood based materials a 1 8 gap will allow for expansion and contraction of the wood based product. James hardie also does not recommend applying caulk to the horizontal overlap between siding planks see figure 2.

On most new homes the trim goes up after the siding is installed which creates a large gap that should not be caulked. Joint flashing is recommended for all hardie lap siding now. We need air circulation behind these boards and the opening acts as a water exit should water ever go behind the boards. 25 4 mm on overlap no caulk figure 1.

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. Deterioration of the caulking in the joint has become a maintenance issue for home owners over time. In the old days the builder would install the trim bring the siding up to it and caulk the corner. James hardie fiber cement siding best practices appendix a 2014 pdf available from james hardie corporation 231 s.

Lasalle st suite 2000. 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. Hardie no longer recommends the caulking of any joint in their lap siding colorplus or primed. Because almost all of the james hardie product installed in edmonton is prefinished colorplus siding the caulking will.