Insulation For Flat Roof Without Attic

Flat roof in many cases it is easier and more cost effective to insulate a flat roof internally using insulated plasterboard.

Insulation for flat roof without attic.

Chauk line to idenify where your rafters are. Attics or roofs without a working space are covered later in this chapter in section 5 4 cramped attics cathedral ceilings and flat roofs. I was planning on using a vented attic unless i spray foam it of course. If you put cellulose up there it will help insulate but you need a vapor barrier above the ceiling because you ll have warm ceiling air hiiting colder roof surface and condensing which will turn the cellulose into a moldy mess.

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. Unvented flat roofs a technical discussion flat roofs have often been built with the insulation all on top of the vapor closed drainage plane as this avoids dew point condensation issues inboard of the roofing. Fill the area with 1 5 inches thick polyiso. Because most flat roofs don t have an attic crawl space or venting the insulation must go underneath the roof s covering on the exterior of the home or be placed on the inside of the home.

The house has a 1 12 pitch roof. 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. An attic you want vented but in your case you want the ceiling roof space sealed. 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.

Assessments in addition to checking for structural problems check the condition of the roof framing sheathing finish and the soffit and fascia for signs of moisture problems such as leaks stains mould flaking or rot. Unless you re using mineral wool insulation or your fixtures are rated safe for contact with any type of insulation don t allow the material to touch or cover recessed cans or lights from the floor below it s a fire hazard. We ve had a new 60 mil gaf tpo roof system put on our house. Running with the slope lay 1x4 lumber flat onto the insulation 2ft o c.

However in many situations the insulation may need to be primarily or entirely below the flat roof membrane and between the roof joists if so what are the best options. Cathedral without any attic space. A 1 5 inch polyiso insulation was installed under the tpo with a 2 4 boarder as a nailer support. Use construction adhesive between 1x4 and insulation board.

A homeowner s guide to attic and rafter insulation. This means lowering the height of the ceiling but may be a better option than insulating externally. Run a 2x4 flat around the parmiter of the roof. Starting at one edge accross the roof to the other edge.

Strip off the roof. Box out light fixtures. So glad i found your site. As it sits i.