H Flashing Siding
Begin at either end of the wall and set the level middle section of the z flashing onto the top edge of the siding panel with the wider flange upward and against the wall framing.
H flashing siding. Allows for proper spacing between siding materials and roofing decks driveways or sidewalks. This has proven problematic over time as caulking the joint results in unsightly surface appearances due to the different textures as well as resulted in failure of the caulk joint and associated. We point out that retrofitting these products while a nice idea may be tricky jamming the h up under nailed lapped siding above and will still be visible even perhaps leading to color differences as the two materials flashing. Joint flashing butt joint horizontal lap treatment june 2014 james hardie does not.
This h molding joint eliminates the need for caulk and has an authentic woodgrain appearance with the durability of fiber cement. Flush the end of the flashing length with the wall corner and secure the flashing to the framing with an 8d nail at each wall. James hardie also does not recommend applying caulk to the horizontal overlap between siding planks see figure 2. A common problem with cement board siding products and some other types of horizontal lap siding is that older installation guidelines called for caulking the joint instead of flashing the joint.
We tried a sample h flashing product too short for actual use and found it was difficult to install and risked cosmetic damage to the siding. Install the first length of z flashing. James hardie does not recommend using caulk or h jointers for the butt joints of hardieplank siding with colorplus technology.