Existing Roof Insulation

Single ply roof systems can provide an easy to install seamless roof assembly.

Existing roof insulation.

Water is insulation s enemy. Box out light fixtures. Rockwool multifix is a mineral fiberglass faced stone wool product that can be installed under many single ply membranes. 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.

Single ply roof insulation. Overlap each sheet by six inches and use nails or staples to fasten it. Alternative options for insulating old roofs. Lay the wood perpendicular to the roof joists and use roofing nails to fasten it in place.

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. Here s how to insulate your new or existing roof. 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. Install plywood to act as structural roof sheathing.

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 is an acceptable practice to install a new roof over an existing roof membrane system provided that the roof deck is. 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. There is a good deal of controversy around these systems.

One modern option for existing buildings is sprayed foam. The proportions do not matter but this arrangement helps to eliminate any draughts caused by gaps between the insulation and the rafter. 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. Existing ceiling wall or floor cavities that are exposed provided the cavities exposed are filled with insulation.

Now comes the really really big point. How to install insulation board over an existing roof membrane.