Insulation Against Roof Sheathing

Box out light fixtures.

Insulation against roof sheathing.

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. Use rigid foam insulation to cover wider spans of roof sheathing between joists. Most building codes including the international residential code allow just one exception to these rules. It creates a breeding ground for mold and mildew and ruins the air trapping pockets that block heat flow.

In climate zones 2b and 3b you can install fiberglass insulation against the underside of your roof sheathing without a ventilation channel or rigid foam above the sheathing but only if you install tile roofing. The moisture is held in place by the insulation which allows for damage to the framing and other building components. 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. 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.

This retrofit assembly is appropriate for homes with conditioned attics or where the retrofit is intended to create a conditioned attic. This system works. T he problem with the insulation against the sheathing expands. Water is insulation s enemy.

Install insulating sheathing above the roof deck on existing homes. Remove existing roofing and non adhered underlayment to expose roof sheathing. Radiant barriers are utilized to reduce summer heat gain in attics and help to improve the efficiency of green building envelopes. The home builder used 1 2 polyisocyanurate as an interior vapor barrier under 1 2 drywall.

If there is a roof leak the insulation will be damaged by the water leaving you with less insulating value. Cut each sheet to the desired size using a utility knife then fasten it in place using staples or adhesive. A layer of spray polyurethane foam can be installed against the underside of the roof sheathing with the rest of the rafter cavity filled with air permeable insulation. We take a look at how radiant barriers work the different types of radiant barriers and some of the.

Exterior has a 1 2 thick drainage board and building paper against the sheathing where the thinstone veneer is attached to this specialized system designed for stone. The problem arises with moisture.