Fanfold Behind Siding

Dupont has said on their website and product flyers that if using both fanfold and housewrap and committed to both put the tyvek housewrap over the fanfold but they actually recommend assuming the insulation is totally closed cell with very low absorption rate putting the insulation directly under the siding overlying dupont drainwrap which is designed to provide a better drainage path between the two than regular housewrap.

Fanfold behind siding.

Products can be used on wood steel framing or concrete walls. Fanfold foam residing board product data sheet pdf 783 kb. Fanfold foam residing board. 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.

Generally the thicker the foam the greater the insulator. Foam insulation is often referred to as fanfold. When every penny counts you can rely on the performance of our most economical fanfold siding underlayment. Exterior insulation is a foam like layer that is applied under the new siding.

It also helps to level the walls so you get a better smoother siding job. Fan fold is typically sold in 1 4 inch by 4 foot by 50 foot sections and is installed horizontally across the existing siding to level out irregularities before re siding with vinyl. Like bob said it helps with sound insulation. Fanfold foam residing board is a thin perforated extruded polystyrene foam board faced on one side with a plastic film facer and combines proven xps foam technology with a unique design to enhance the application of new or replacement siding.

I have not seen any studies that show how well tape adheres to foam over the long haul. Generally referred to as rigid foam insulation this type of foam insulation is also called foam board foam plastic insulated. Considering how effective house wrap is and how simple it is to install behind vinyl it is a good idea to ensure your contractor includes it when siding your home. This is because some brands of foam insulation are stored folded and it unfolds like an accordion for easy installation.

This creates a horizontal seam every 4 feet. It also serves as an air barrier. 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. The products are easy to handle score cut and install and no special tools are needed.

While fan fold has minimal insulation value it does even out wall defects and cuts down on drafts. Also during this siding process you may also consider asking your contractor to add foam insulation between the vinyl and the house wrap for increased r value. Fanfold board is worth the cost and effort to install behind vinyl siding. Fan fold comes in foam sheets and is nailed directly to the sheathing.

It also helps with wind infiltration through the walls.