Rigid Foam Roof Sheathing

Cold formed metal framing c.

Rigid foam roof sheathing.

Rigid foam insulation packs a lot of r value into a thin package but not all rigid foam performs the same. You can even place it under the foundation slab. 1 inch and 2 inch thicknesses are common. Replacement of a roof membrane where either the roof sheathing or roof insulation is not exposed or if there is existing roof insulation below the roof deck.

Install nailbase for cladding. Alterations to roof ceiling wall or floor cavities which are insulated to full depth with insulation having a minimum nominal value of r 3 0 in. Air barrier system 4. The boards are available in several thicknesses and r values.

Rigid foam sheathing 3. On the gable ends this was pretty easy. Polyiso consists of a uniform closed cell polyisocyanurate foam core and provides one of the highest r values per inch of any rigid insulation. Rigid insulation sheathing is made of a rigid plastic foam that is typically sold in 4 8 or 4 10 foot boards.

Not only that foam sheathing will soon be mandated by code in some climate zones. Exterior rigid foam improves air tightness adds r value reduces the chance of condensation in wall cavities and greatly reduces thermal bridging through studs. This foam is applied over the top of the membrane that came down from the roof deck catching the wall control layers. Rigid insulation is one of the best tools to reduce your energy costs.

Detail roof wall intersection and all openings and penetrations to provide a continuous air barrier system. Rigid insulation layers exterior to existing roof sheathing must provide sufficient thermal insulation r value to control condensation risk see climate specific guidance. Metal panel on metal framing figure a 1. The purpose of the requirement that rigid foam installed above roof sheathing meet certain minimum r values is to ensure that the roof sheathing stays warm enough during the winter to avoid moisture accumulation and possible sheathing rot.

Choose rigid insulation wisely and consider the effect its characteristics will have on the performance of the your project overall product cost and the best way to get the bang for your buck. Install rigid insulation board in multiple layers with joints offset vertically and horizontally between adjacent layers. Rigid foam insulation also known as insulating boards provide high r values. Rigid insulation provides thermal protection and it can also serve as an air and moisture barrier.