Installing Fiber Cement Siding Over Rigid Foam

Shawn sell of my guys remodeling explains how they installed new fiber cement with fullbackfc siding insulation for fiber cement and halfbackh20 siding insul.

Installing fiber cement siding over rigid foam.

Exterior rigid foam w modern hardie plank siding details february 13 2013 exteriors insulation air sealing siding i ve become a big fan of utilizing outsulation on all my houses over the last 2 3 years. We put 2 x 4 furring studs laid flat over the foam and attached to the wall studs with 1 5 inch foam between the furring studs rain screen over everything and finally the lp siding. Siding installation starts at the bottom flush with the bottom of the sill plate and each successive siding strip installs above the previous one. This only increases the wall thickness 3 4 inch vs the furring strips william costello was planning to use and would only require increasing the interior window sill by 3 4 inch.

In a typical situation. The old vertical cedar siding looks to be nailed into horizontal strapping 3 4 x 3 5 i believe. Siding over rigid foam exteriors. The furring strips are attached to the studs with 4 screws at 6 to 8 o c.

We recommend performing a small siding mockup prior to installation to ensure the fastening practice and or fastening tools are properly adjusted. I install 1x furring strips vertically over the foam to support fiber cement lap siding. If installing their fiber cement siding directly over rigid foam they do not recommend any more than 1 of rigid foam and they seem to prefer no more than 1 2 of rigid foam the main concern being that the nails will sag if driven through anything thicker than 1 of rigid foam. Most types of vinyl fiber or cement fiber siding install after the trim is in place.

Insert siding nails every 16 inches into the furring strips but do not insert nails between the strips. Installing fiber cement siding over rigid foam sheathing i have completed several projects that use foil faced polyiso as the exterior rigid insulation board. Almost any type of siding can be installed over the rigid foam cedar or redwood planks exterior plywood sheets cement fiber board or vinyl siding are common options.