Foam Board Behind Vinyl 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.

Foam board behind vinyl siding. 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. We knew we had to use the 76 series smartside product for the 24 inch centers. The foam board is nailed in place with washer head nails should be taped at the seams to prevent air movement. This detail is used with both new construction and also with renovation work.

You need to supply an air space behind the siding where incidental water can drain and the. 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. 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. The products are easy to handle score cut and install and no special tools are needed.

Then i discovered that lp s installation instructions specify 1 5 inch x. 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. Foamular extruded polystyrene xps rigid foam insulation offers a comprehensive line of products in a wide choice of sizes thicknesses and edges with a lifetime limited warranty for the life of the home or building. This is most common with vinyl siding.

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. We re building a new home sw virginia with 2x6 studs on 24 inch centers. It also serves as an air barrier.

Insulated vinyl siding is standard vinyl siding with a backing of solid rigid foam insulation. In a typical situation. 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. But if you use wood clapboard siding foam sheathing can cause trouble.