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Installing R30 15" in attic but my trusses are 24" OC

Installing R30 15" in attic but my trusses are 24" OC

Old 01-09-11, 05:35 AM
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Installing R30 15" in attic but my trusses are 24" OC

The local big-box stores have R30 with 15" width and I purchases 12 bundles to get me started but the spacing on the trusses is 24". If I put the insulation between the trusses, I'm going to have a sizable gap on the sides. I'm thinking about rolling the insulation the opposite direction, perpendicular to the trusses.

Will I get decent performance out of this installation method or should I search for insulation that fits well in my trusses?
Old 01-09-11, 06:04 AM
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You should be able to buy rolls of insulation in 2 different widths - to fit 16" oc and 24" oc.
Is there currently insulation in the attic? or is this new construction? You can't leave a big gap under the insulation or along side it. If you have to use the 16" rolls, you'd need to cut them to fill the entire cavity.
Old 01-09-11, 06:59 AM
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How deep are the trusses? If you can't get 24" wide insulation, I would get batts that were as deep as the trusses. Instead of rolling them across, cut them to 24" (or whatever the distance is) and fit them in that way. I would then roll additional batts on top of that, perpendicular to the first layer. That would be parallel to your truss. The second layer of insualtion needs to be unfaced and whatever thickness you need to get your desired R factor.

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