Solid Batt Insulation Sloped Roof

If you want to vent a low slope roof here s what you need to do.

Solid batt insulation sloped roof.

Sloped roof insulation providing high quality insulation between cathedral ceiling roof joists is an easy method of improving the overall energy performance of a building. Ratio of r value between rigid insulation and batt insulation is climate dependent. Batt insulation relatively cheap in bulk quantities such as is the case with this owens corning r 38 fiberglass batt insulation roll designed to fit up to 341 36 square feet of attic space. 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.

Of insulation plus room for an air gap of at least 6 in. Framing this out and buying 30 r fiberglass insulation will cost you about 50 more than just buying 5 inches of polyiso equivalent of 30 r. Currently the built up asphalt roof is installed over homasote or something similar and a roof deck made of wood planks. Composite insulation works in flat and low sloped roofs with a variety of roof coverings.

Specify roof trusses or conventional framing deep enough for 12 in. 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. Air permeable insulation such as fiberglass batts dense packed cellulose or blown in fiberglass can t be used alone for an unvented assembly since these types of insulation can allow moist indoor air to reach the cold roof sheathing leading to condensation or moisture accumulation. Then install r 30 fiberglass batts between the rafters.

Composite insulation reduces the need for a cover board when applying different membrane roof coverings. Rockwool comfortbatt is a stone wool insulation that provides reliable thermal resistance over time. Keep in mind that this is the roll and not the loose fill. He plans on replacing the low slope built up roof with an epdm membrane and the question is how to insulate it correctly.

Between the top of the insulation and the roof sheathing. The level of additional insulation will depend on the product chosen and the depth of the rafters. Roof insulation refers to the practice of installing insulation on the roof slope. It should be installed on tapered 2x furring strips in order to slope the surface of the roof to drains.

All additional insulation must be secured to hold it in place. In cold and very cold climates selecting a roof deck condensing surface temperature criteria of 45 f is very conservative. An unvented assembly can perform well but it s important to get the details right to avoid sheathing rot. Fiber glass batts should not be compressed.