Insulating Attic 2x4 Rafters

Two knee walls with no insulation 6.

Insulating attic 2x4 rafters.

Whether there is a real hazard or not depends primarily on your local climate climate zone as well as your shingle color type and shading factors. There are four roof mounted vents no ridge vent no gable vents 4. If your attic is going to be converted into livable space then you will need to insulate the roof rafters. Put insulation meant for 2x4 framed walls between the joists which will be the same height as the joists then lay a perpendicular layer of attic insulation maybe r 30 on top of them.

2x4 on 24 center rafters 3. Let s say you ve 384 sqft of ceiling to cover. A drywall sheet is 32 sqft. It lowered my heating bill by 150 month but i ve seen some information that i may have made a mistake by cutting off the airflow in my attic.

I would really like to get more than r 13 and the current installation is probably providing r 1 with all the missing pieces. If your rafters are only 2x4 either you ve got about 400 sqft or you ve reinforcement load bearing partitions beams somewhere. Option 2 has the benefit of preventing any thermal bridging via the ceiling joists. 2x6 on 24 center floor joists no insulation between joists 3.

Hire a pro to install spray foam insulation. Install ventilation baffles into the space between the rafters before you install the insulation usually by stapling into place. They are directly below the roof sheathing and are were insulated with fiberglass batts stapled between the 2x4 rafters. If you re considering turning your attic into conditioned storage or living space it s worth changing tactics to insulate between the rafters and wall joists instead of the floor.

Shaded or north facing roof pitches would be the most susceptible but with only 2x4 rafters and likely r13 or less the roof deck runs warmer drier than if it were insulated to current code min. I added insulation to my attic rafters and plugged the space between the outdoors and my attic with insulation.