MANUALS AND CODES
SIDING
THINGS TO REMEMBER
SIDING PENETRATIONS (LARGE)
For penetrations in the building envelope such as hose bibs and holes 1½ in diameter or larger, such as dryer vents, a block of HardieTrim® 5/4, 4/4 boards shall be installed around the point of penetration.
Blocking should be a minimum 3 in radius greater than the radius of the penetration. To install a block around an existing vent pipe, it may be necessary to cut the block into two pieces. In this case, weather-cut the trim to fit it into place. Install flashing over the top of the trim block.
SIDING PENETRATIONS (SMALL)
For small penetrations such as wires, electrical conduit, and pipes less than 1½ in. in diameter (excluding hose bibs) no blocking is necessary.
The circumference of pipe or wire should be sealed with a barrier foam and/or caulked.
GUTTERS
If gutters are installed, they should not terminate against siding or trim. Maintain a 1 in. clearance between the siding and the gutter end-cap. Kickout flashings should be installed on the roof above to divert roof runoff into the gutters and away from the 1 in. gap.
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The amount of water that can be generated from a rain shower or storm can be substantial. Managing the collection and distribution of this water is important over the life of a home.
MASONRY/MORTAR
James Hardie® siding and trim products should not be butted directly against mortar or masonry, including stone, brick, or concrete block. In these situations, flashing should be installed to isolate the trim or siding from the mortar or masonry.
HARD SURFACES
A clearance of 2 in. must be maintained between James Hardie siding and trim products where they meet roofs, decks, paths, steps, driveways or any other solid surfaces.
HARD SURFACES (SHELTERED)
Maintain a ¼ in. clearance for HardieTrim boards installed under cover. Undercover is defined as:
-
Not more than 10 feet below
a roof overhang, and -
Not less than 4 inches horizontally from the edge of the roof overhang
VINYL SIDING
OVERLAPPING CORNER POSTS
If more than one length of corner post is required, overlap the upper piece over the lower piece by cutting away 1" (25.4mm) of the nailing flange on the top piece. Overlap 3/4" (19mm), allowing 1/4" (6.4mm) for expansion.
This method will produce a visible joint between the two posts, but will allow water to flow over the joint, reducing the chance of water infiltration
J-CHANNEL OVER ROOF LINES
Keep the J-channel a minimum of 1/2" (12.7mm) from the roofing material due to possible heat transfer to the vinyl J-channel causing distortion. Darker roofs may require metal j-channels.
J-Channel Weep Holes
The top piece of J-channel must have minimum 3/16" (4.8mm) diameter weep holes drilled no more than 24" (610mm) apart to allow for water runoff, and the starter strip (J-channel) should not rest on head flashing because it will block weep holes. Leave a gap as shown (Figure 49).
