Expansion Gap For Siding

Vertical trim gap caulking.

Expansion gap for siding.

When installing in freezing weather below 40. And it can move a lot through expansion and contraction especially along the length of the clapboard style panels. For horizontal applications start with the bottom course and work up with the channels pointing upwards. If the panels are 20 feet 6 1 meters or longer refer to the manufacturer s instructions for how to increase the gap.

Siding must be cut in lengths to provide for expansion. To avoid structural or aesthetic problems associated with temperature fluctuation take the following steps. Vinyl siding must be nailed so expansion and contraction are not restricted. Do i need to seal edges at a butt joint.

By obtaining some additional siding and carefully preparing it small pieces can simply be snapped into place covering the wide gap your home builder is forced to leave for expansion. James hardie recommends that a slip sheet joint flashing is installed behind each butt joint in the siding. These will serve as starter strips in which to lock the vertical siding. Increase to 3 8 9 5mm when installing in temperatures below 40 f 4 4 c.

Allowance should be made for expansion and contraction by leaving a 1 4 6 4mm gap between the siding and all corner posts and channels. Allow for expansion and contraction. Gap for expansion wherever siding butts accessories. Lap siding can be installed horizontally or vertically.

Leave a 1 8 gap between the siding and the trim or other materials to allow for structural movement. Allow a 1 4 in. Choose the right nails. Always caulk between the siding and the trim.

Vinyl siding contracts and expands as the outside temperature changes. Do not nail through overlaps. Hardie boards should be joined in moderate contact. Allow a 1 8 inch expansion gap between pieces if the siding is air or kiln dried.

This means that the boards should be touching each other when they are installed. For siding up to 6 inches wide use one nail one inch up from the lap. Leave 6 4mm gap at the top and bottom. If you are using primed siding you must seal all exposed cuts of siding including those at butt joints.

By having the small additional overlapped piece of siding you are still allowing for expansion but you are effectively covering all the gaps in the siding. There is no need to leave a gap for expansion. To compensate for this movement adjacent siding panels are overlapped so that they can slide sideways past each other without buckling or creating gaps see nailing details and expansion gaps.