Best R-value (wood or 3/8 " drywall


Old 10-16-10, 08:11 AM
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Best R-value (wood or 3/8 " drywall

Title pretty much covers my question. I need to replace the drywall on the ceiling of an addition to the house. I was wondering which would give me the better insulation value. I really like the looks of stained bead board for the purpose of the room (card playing and pool table, not an acutal living area.

Many thanks in advance....
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Old 10-16-10, 12:21 PM
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While I'm sure there might be an R value difference between the 2, it would be minuscule. It would be better to add sufficient insulation and then apply the ceiling material that best suits you.
Old 10-16-10, 12:54 PM
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As Mark stated, not much difference in R-value. Part of the answer would depend upon what else is up there for insulation. If there is already anything, then air sealing would be the only value to either. If there is nothing, then even a layer of fan fold all taped up to seal the leaks would be a benefit, not a lot, but some. Then add the bead board for looks.

Of course you can go with 1/2" or more of rigid foil faced foam board and then cover it.

Old 10-19-10, 07:21 AM
Join Date: Aug 2009
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R value of 3/8" drywall is .40 or lower (per wiki and next link I'll give you, I averaged them out) Drywall - Wikipedia, the free encyclopedia. R-value of plywood is 50% higher at the most, according to this R-Value Table

Basically the difference between drywall and wood is virtually no insulation and virtually no insulation + a tiny bit of negligible insulation; neither one will insulate to any meaningful degree so I think it's moot from that end. Even a half inch of extruded polystyrene will give you 2.5R value, so if you can get a little foam on the go now you're really talking.
Old 10-19-10, 10:52 AM
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Do not spit hairs on something so unimportant. Both have an R-value less than the thin layer of air that is assumed to be on the interior surface of a wall.

Old 10-19-10, 11:47 AM
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Yep, 1/2" drywall over 1/4" plywood by 0.14, and for our next hair-splitting race...... - R-Value Table

Old 10-19-10, 04:16 PM
Join Date: Aug 2009
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o0o0o0oo0. I will be bookmarking that for the next ridiculous conversation I have with my brother. I'll just have to remember where in my bookmarks I put it.

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