Cedar shingling over continuous rigid foam
I recently installed a siding product on a house called “Shakertown” as part of a remodel. The product consists of western red cedar shingles glued and stapled to a plywood backer. The product installs just like clapboards in 8’ long sections with a pre set course exposure. There are pre woven corners that are staggered to offset the joints in each course. I’m wondering if anyone has tried a product like this directly over continuous rigid insulation? Seems like one could potentially exclude the extra materials and labor of strapping over the rigid if wood shingles were desired using a product like this. The plywood backer on this product is effectively the same thing as a strapping nail base. There is another company making a similar product called “Cedar Valley”. Both of these products are made with western red cedar which is not my preferred choice of cedar. Living in New England I would prefer eastern white cedar but in the interest of time and material savings i might consider this panel product. Any experience or thoughts on installing this stuff directly over rigid foam? Thanks Ted
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
I looked quickly and it doesn't seem that either of the companies give installation instructions for fastening the panels over rigid foam insulation. So, the first thing you'd need to do is check with the company and discuss warranty issues and to determine what the appropriate fasteners are, which isn't always as simple as choosing longer fasteners to get the same amount of penetration into the framing.
Some of the Shakertown panels have grooved backs which they claim to be effective at creating a rainscreen. I find it hard to believe that a few grooves would be as effective as an actual built, ventilated rainscreen gap that has many benefits for both the longevity of the siding and health of the wall. But it may provide some drainage, similar to a draining housewrap.