Why Put Fanfold Polystyrene Under Siding

This creates a horizontal seam every 4 feet.

Why put fanfold polystyrene under siding.

I thought i should show why continuous foam under the exterior siding is so important. Why insulation under the siding is important. I am having the siding removed from our house and 2 foam board but under the siding. 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.

The house was build in the 19970 s 2 4 walls and pink insulation between the studs. 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. This foam board insulation is the rigid pink or blue panels that can be found at home centers in many different thicknesses. I get asked if this or that in the in the cavity works as well as foam under the siding.

It provides an r value of 4 per inch of thickness and is the cheapest type of foam board insulation. 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. 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. I have not seen any studies that show how well tape adheres to foam over the long haul.

Let s take a look at each. The windows are being removed and moved out the 2 to line up with the foam board. However another important consideration is what to put under your siding. 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.

By glenn hooper june 2 2015. It also serves as an air barrier. This generally means choosing between tyvek homewrap made by dupont since it is the most popular brand and exterior fanfold insulation. The house has wrap under the siding.

Eps is used under roofing over foundation walls and beneath siding. Will this cause any condensation issues. Fanfold foam residing board.