Using Rigid Exterior Insulation Under Hardishingle Siding

I d like to side it in fiber cement siding to match the existing house.

Using rigid exterior insulation under hardishingle siding.

These irregularities should be corrected before the siding is installed. Several manufacturers of rigid foam insulation recommend metal strap bracing as a structural solution for foam sheathed walls. Rigid insulation provides thermal protection and it can also serve as an air and moisture 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.

So using 1 4 let in braces may not be an automatic solution when building foam sheathed walls metal bracing may not be the answer either. Addition to my house. When using continuous insulation foam sheathing avoid over driving fasteners which can result in dimpling of the siding due to the compressible nature of the foam sheathing. Always follow the manufacturer s instructions for installing rigid foam insulation.

To secure the foam use two inch cap nails. I m an architect in wisconsin climate zone 6b and am planning to build a 300 s f. The method works for both new construction and remodeling and doesn t affect siding and trim details very much. 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.

Most homes in the united states are built with traditional wood frame construction with studs every 16 on center. The nails have a plastic cap that keeps them from damaging the foam. How to install rigid foam under siding. Continuous insulation under new siding has become a popular way to improve energy efficiency on an existing home because it addresses a problem known as thermal bridging.

Fit the rigid foam insulation snugly and seal all. Some people use roofing nails but if a strong gust of wind gets under the siding it may not hold. Under driven nails can telegraph through to the fi nished siding and trim. The boards are available in several thicknesses and r values.

According to my calculations if i want to use rigid foam insulation on the outside of the 2x6 walls with r 21 fiberglass in the wall cavities i need at least r 11 25 in order to avoid condensation on the inside. Building codes allow them as substitutes for 1 x4 let in braces. There are three primary types. Using exterior rigid foam board insulation is a great way to make a building more energy efficient quieter and more likely to prevent moisture infiltration problems.

Bottom line is exterior foam insulation is a good investment.