Foam Board Behind Vinyl Siding

This is most common with vinyl siding.

Foam board behind vinyl siding.

By filling the voids behind the siding s stepped profile the insulation makes the complete material stiffer and more resistant to warping and movement than conventional vinyl siding. But if you use wood clapboard siding foam sheathing can cause trouble. Insulated vinyl siding is standard vinyl siding with a backing of solid rigid foam insulation. 1 2 polystyrine foam board insulation this is typically used to go over the existing siding in order to create an even surface to keep the siding plum during installation.

This detail is used with both new construction and also with renovation work. 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. Products can be used on wood steel framing or concrete walls. The foam board is nailed in place with washer head nails should be taped at the seams to prevent air movement.

Installing foam insulation under vinyl siding is a wise choice for homeowners who are seeking to protect their homes against moisture infiltration as well as improve energy efficiency. Installing foam board insulation under vinyl siding today more than ever before homes are being built with foam board insulation installed on the outside of the sheathing and under the siding. The by the book answer to your question is that vinyl siding manufacturers require a flat solid supportive surface and limit foam installed under their siding to a maximum of 1 in. The products are easy to handle score cut and install and no special tools are needed.

It also serves as an air barrier. In reality rigid foam board which sometimes comes in fanfold usually only has an insulating factor of r 1 and does not add any appreciable insulation effect to your home. We had hoped to use 1 5 to 2 inches of eps rigid foam to the exterior of the sheathing then 3 4 inch x 4 inch plywood furring strips then lp smartside lap siding. In a typical situation.

And even though some manufacturers call it rigid foam insulation for the purpose of vinyl siding it basically has the same insulating value as a piece of plywood. Then i discovered that lp s installation instructions specify 1 5 inch x. Hollow vinyl solid pvc. We knew we had to use the 76 series smartside product for the 24 inch centers.