I have a tongue-and-groove vaulted ceiling. How can I insulate it?
MorganSB
| Posted in Energy Efficiency and Durability on
I live in Santa Barbara California. I have a tongue and groove ceiling in living room and dining room and ceiling is vaulted to about 18+feet. The shingles on the outside were applied directly to the plywood covering the tongue and grove (I guess there is that black barrier stuff/paper between). But no other insulation or barrier was applied. These are asphalt shingles.
Recently lost some Oak trees that provided substantial shade to roof, now nothing….how do I insulate this? In the summer with sun overhead it gets close to 110 degrees in the Living Room. I do not have air conditioning…..please help. Thank you Kathie M.
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More information needed - post some photos of the ceiling, especially where it abuts the exterior wall on the rake. Do you by any chance have glass going right up to the ceiling at the rake, i.e. the top of the sloped wall?
Kathie,
Although you didn't provide a full description of your roof assembly, I think I know what you are describing. I'll assume that your house has exposed rafters that are visible from the interior. Above the rafters is a layer of tongue-and-groove boards (also visible from the interior). And above these boards is a layer of plywood roof sheathing, followed by asphalt felt underlayment and asphalt shingles.
The best way to insulate this type of roof is to strip the shingles. Then install a thick layer of rigid foam insulation, followed by a second layer of plywood or OSB sheathing, followed by another layer of asphalt felt, followed by new roofing. (A variation of this approach calls for the use of nailbase, which is rigid foam insulation bonded to OSB on one side.)
If you don't want to take this approach, you can install some type of insulation between your rafters, and then a new gypsum drywall ceiling under the rafters. There are three disadvantages to this approach: (1) you will probably end up with a lower total R-value, (2) you will still have thermal bridging through the rafters, and (3) you will no longer be able to see your tongue-and-groove boards.
For a more thorough discussion of all your options, see How to Build an Insulated Cathedral Ceiling.