Box out light fixtures.
Insulation for flat roof without attic.
The house has a 1 12 pitch roof.
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.
I was planning on using a vented attic unless i spray foam it of course.
An attic you want vented but in your case you want the ceiling roof space sealed.
Cathedral without any attic space.
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.
This means lowering the height of the ceiling but may be a better option than insulating externally.
Compromising the effectiveness of the insulation.
We ve had a new 60 mil gaf tpo roof system put on our house.
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.
So glad i found your site.
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.
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.
A homeowner s guide to attic and rafter insulation.
A 1 5 inch polyiso insulation was installed under the tpo with a 2 4 boarder as a nailer support.
Zone is 6 my hdd is 7200 and design temp is 20 although that is fairly extreme and probably in the 98th percentile.
Chauk line to idenify where your rafters are.
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.
Run a 2x4 flat around the parmiter of the roof.
Use construction adhesive between 1x4 and insulation board.
Starting at one edge accross the roof to the other edge.
Attics or roofs without a working space are covered later in this chapter in section 5 4 cramped attics cathedral ceilings and flat roofs.
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.
Fill the area with 1 5 inches thick polyiso.
Running with the slope lay 1x4 lumber flat onto the insulation 2ft o c.
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.
As it sits i.
The ceiling is flat the roof will be a 2x4 truss system with a 1 energy heal on the double stud wall.
