Residential Oversheathing Roof Insulaiton
Over roof insulation the gable overhang has been cut flush with the wall sheathing.
Residential oversheathing roof insulaiton. Johns manville r panel rigid roof insulation board offers r values of up to r 23 6 providing high thermal efficiency. Don t let your heating costs go through the roof. Standard or dark roofs can reach temperatures of 150 f or more in the summer sun. Insulated roof assemblies can be vented or unvented.
Install insulating sheathing above the roof deck on existing homes. A roof over a vented unconditioned attic does not need to include any insulation. Cool roofs can be made of a highly reflective type of paint a sheet covering or highly reflective tiles or shingles. The tight building envelope protects the wall system from water and air infiltration and contributes towards continuous insulation.
The base wall assembly generally remained unchanged with other materials used for air sealing and water management. A cool roof under the same conditions could stay more than 50 f cooler and save energy and money by using less air conditioning. Made of a high density rigid polyisocyanurate core and coated glass fiber facer it combines the weather barrier and sheathing functions allowing completion of the building envelope to be faster and more cost effective. With this kind of roof the insulation follows the slope of the roof.
Remove existing roofing and non adhered underlayment to expose roof sheathing. However most cathedral ceilings and low slope flat roofs are insulated roof assemblies. In fact all grades of thermo brace have been evaluated and permitted as a water resistive barrier wrb noted in irc section r703 2 and ibc section 1404 2. This retrofit assembly is appropriate for homes with conditioned attics or where the retrofit is intended to create a conditioned attic.
Start at the bottom of the roof and place the first piece of rigid foam insulation against the metal flashing starting at the center line. Also note that a new fully adhered membrane is installed on the original roof deck replacing the one installed 17 years ago is folded down to catch the top edge of the wall water control layer. Nail it around the edges with roofing nails. An addition to standard residential construction for a specific purpose.
Goboard structural sheathing is an ultra lightweight yet durable waterproof alterna tive to heavy sheathing products. With more than 60 years of being used nation wide insulfoam roof insulations are a proven value.