Roof Insulation For 2x4 Rafters

There are some unfinished crawl space areas in the corners on the upper floor.

Roof insulation for 2x4 rafters.

For instance 2 grade 2x4s at 16 on center will span just over 9. So at 16 oc each joist is 2 2x4s together. If your local building authority has a rafter spacing code you may not space rafters wider than required by code. It s easy to say oh yeah just put 1 2 drywall on your ceiling forgetting that it weighs over 50 pounds.

Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run. We just had rebuilt repaired the roof of a flat roofed addition to our house due to a roof leak and resulting breakdown and mold problems. A drywall sheet is 32 sqft. The original roof ceiling was framed with doubled up 2x4 joists for extra strength.

For standard shed roof rafter spacing see rafter span chart. Install a timber stop batten across the rafters as shown in position c with the batten equalling the thickness of the quinn therm insulation. Typical rafter spacing codes will specify a minimum spacing of 16 inches 19 2 inches or 24 inches. Rafters must be strong enough to hold the roof sheathing and the shingles.

Let s say you ve 384 sqft of ceiling to cover. There is no standard spacing it depends on what size of rafters you want to use and the span of your shed. For light load roofs 24 o c. The rebuild was done the same way.

Spacing your 2 4 shed rafters at 24 on center limits the width of your roof. 2 4 rafters can span up to 7. If your rafters are only 2x4 either you ve got about 400 sqft or you ve reinforcement load bearing partitions beams somewhere. It s already a low ceiling 78 ceiling on the low side and 87 ceiling on the high side.

Lay quinn therm qr insulation boards above the rafters butted tightly against the stop batten and supported on both sides by the 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. Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch. If you get premium kiln dried lumber then you could span 10 5 with the same size of lumber and.