Installing Wood Siding Over Rigid Insulation

In fact the two products combined make your home super insulated from outside wind and weather.

Installing wood siding over rigid insulation.

The illustration below comes from the vinyl siding institute. The answer happily is yes. Cover the house walls with 4 by 8 foot sheets of rigid foam insulation typically 1 2 to 1 inch thick nailed to wood sheathing with 1 1 2 inch broad headed galvanized nails every 16 to 18 inches. Method 1 james hardie siding installed directly over continuous insulation c i and other non nailable substrates e g.

Installation details are key. The vsi installation manual notes when the fastener must penetrate through a non nailable material such as foam sheathing the thickness of that material. Cladding attachment over thick exterior rigid insulation peter baker p eng. A homeowner in southwest virginia wants to install engineered wood siding over exterior foam insulation but finds that the manufacturer s installation instructions raises concerns he hadn t thought of.

Plus rigid foam insulation applied over the outside walls. Moisture protection and heat buildup. It adds up to a robust system. One of the biggest questions homeowners have about house wrap is whether it can be installed together with foam insulation.

Since foil faced foam is a moisture barrier it should be used with a continuous film vapor retarder on the inside wall. Nailing wood siding directly to foam doesn t work because nails have to be extra long to reach through the siding and foam to a solid nail base. When installing wood siding over rigid foam sheathing you must protect the siding from moisture and heat buildup and use proper nailing. Gypsum sheathing with combined thickness of 1 inch or less method 2 james hardie siding installed to furring strips that are attached through the c i.

Exterior rigid insulation 1x3 wood furring strips masonry structure 2x4 framing attached to surface of masonry. How should wood siding be installed over rigid foam insulation. And other non nailable substrates e g. To siding 1 embedment 3 5 0 5 1 5 1 5.

I don t think builders should install wood siding directly over plastic foam insulation. Wood siding applied directly to foam has a history of failures. Wood siding including cedar siding should be installed over an air space regardless of the type of sheathing used. Julie the installation instructions of the vinyl siding institute and most if not all vinyl siding manufacturers allow vinyl siding to be installed over rigid foam sheathing.

What are the risks of installing cedar siding directly over foil faced rigid foam insulation should tar paper or housewrap be used as well.