Existing Roof Insulation

Here s how to insulate your new or existing roof.

Existing roof insulation. One modern option for existing buildings is sprayed foam. Now comes the really really big point. Alternative options for insulating old roofs. Single ply roof systems can provide an easy to install seamless roof assembly.

Portions of an existing building that are altered in the course of additions alterations renovations or repairs must be brought into conformance with the code with the following exceptions applicable to attic roof retrofit. Hack n stack sealed foam board between the rafters would be better since it s at least an air impermeable insulation but even that would require a vent gap below the roof deck to meet code and you d still be under r38 on that 2x6 rafters unless you fattened it out per holladay s recommendation. Existing ceiling wall or floor cavities that are exposed provided the cavities exposed are filled with insulation. It is an acceptable practice to install a new roof over an existing roof membrane system provided that the roof deck is.

Senior engineer manager at icynene john broniek makes the case for the unvented attic assembly and why insulating the underside of the roof makes sense. The quest for greater energy efficiency in buildings has led to increasing interest and need for insulation improvements in hvac equipment more airtight construction new materials and assemblies. Place layers of building paper over the sheathing. The 6 inches of rigid insulation added to the top of the existing roof deck needed to be done in a manner that was invisible.

Rockwool multifix is a mineral fiberglass faced stone wool product that can be installed under many single ply membranes. Look for water stains on the roof sheathing or damp or moldy spots on attic joists and existing insulation as a clue to where leaks might be. It creates a breeding ground for mold and mildew and ruins the air trapping pockets that block heat flow. Install plywood to act as structural roof sheathing.

Single ply roof insulation. Water is insulation s enemy. Overlap each sheet by six inches and use nails or staples to fasten it. Gable end detail overhang cut and then rebuilt to hide the thickness of the over roofing rigid insulation.

Lay the wood perpendicular to the roof joists and use roofing nails to fasten it in place. Box out light fixtures.