Is there much of an R value to sheetrock?

Dec 03, 2007 21 Replies

I'm getting ready to do the exterior walls in my garage (workshop) here in the Portsmouth, NH area. I'm going to use R-19 exterior (2x6 walls) for the insulation. But I was thinking, they have this silver pegboard at HD that would be kind of cool to use. My question is how much of a loss would I suffer if I JUST used the pegboard and skipped the sheetrock (1/2") altogether? The garage will be heated. The dimensions are 20x20x11 and it is new construction.



Thanks in advance.



-Jim


Sheet rock is normally taped and or sealed at the seams. Normally installed sheet rock will certainly cut down of drafts over pegboard alone.

To amplify Leon's answer -- the R-value of sheetrock is pretty minimal (only a few tenths) but do be sure you have a good windbarrier. Should have one on the exterior, of course, if the builders didn't tear it full of holes and did a good job of it. Wouldn't hurt to add an interior for certain.

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I would think the fire retardation of sheetrock would be a good benefit over the pegboard as well.

R value for drywall is about 0.5 for thicknesses between 1/2 and 5/8.

DonkeyHody "In theory, theory and practice are the same, but in practice they are not."

As others have noted, the fire and draft resistance of drywall are quite important.

A proper moisture barrier is important as drywall will pass water vapor and absorb condensate, becoming gummy and stinky over time.

Interestingly, much of the fire resistance is due to water chemically bound in the plaster. When heated, the water escapes which carries energy away from the drywall, cooling it.

I thought about the wind barrier thing a bit, but the workshop is in the back of the house, it is new and covered in Tyvek (sp?) and Hardi Plank siding. I am going to use 5/8 sheetrock on the ceiling with insulation above it. This is really only for three walls, one of which has the garage door in it, and the other has 4 large windows in it. So the main area is really the one opposite the interior wall and that is about 20x11. I mean, I would only be using the heat on the weekends and maybe occasionally in the evenings, else it would be set down to it's lowest setting so that it wouldn't freeze (FHW)

text -

why not price foam insulation closed cell spray foam is about R6 per inch.

is the slab insulated?

The sheetrock per se doesn't have much R value, but it serves to seal the inner surface of the wall, thus creates a closed air cavity in which convention is suppressed by the fiberglass, so by not using it you may lose more than you would expect just from the R value of the sheetrock.

In a wood shop I think you'll find that fiberglass behind pegboard is a continuing annoyance--pegboard holds amazing amounts of sawdust that comes out at inconvenient moments, so does fiberglass. The two together, well you may end up needing to put up another building in which to apply finishes.

Could you and should you are two different things.

The biggest benefit of sheetrock is to protect the plastic vapor barrier. So if you put up peg board the punch through the plastic (and you will at some time), you let the moisture in and it will condense in the insulation.

Why not put up the drywall, prime & or pain tit, then use nuts (spacers) to mount partial sheets of pegboard. You need a little gap to re&re the hangers of all types. I have extras. Theres 2 standards, and I garbage pick hangers all the time. Sams as all stores. Proportion sheets, orient, and space on walls to suit each or all. I did it in my garage. Besides, aligning the holes with spacers with whole sheets is tricky. I have third sheets with 1-1/2" between them. Doesn't take too many screws/bolts .

The most additional "bang for the buck" would undoubtedly be in an insulated door and better windows if either or both are not presently.

The floor slab is a big heat sink as haller notes if there's not been any consideration of doing something there...

On Dec 3, 11:40 am, "bent" wrote: "pain tit"?

Maybe you should have that looked at...

'Rock may be required by code if it's in a garage, because it doesn't burn well.

And in some places the sheetrock will be required by code, for fire prevention purposes. Doing things to code will be important when you eventually sell the place.

That's something I can speak to. 1/3 of my garage is pegboard over insulation. That's were my shop area is. The other two bays are sheetrock. It's been this way for almost 15 years. I paint cars in those other two bays and I've never had an issue with sawdust.

It might well be argued that sheetrock would have sealed over my insulation better than the pegboard does, but in Central NY where the winters are cold and blustery, I've never noticed any real shortcoming with what I have.

"J. Clarke" wrote The sheetrock per se doesn't have much R value, but it serves to seal the inner surface of the wall, thus creates a closed air cavity in which convention is suppressed by the fiberglass, so by not using it you may lose more than you would expect just from the R value of the sheetrock.

It's interesting you should say that. It's been explained to me that in fire-resistant safes, such as gun safes, that several layers of sheetrock are used to protect the interior of the unit.

Now, exactly what kind of sheetrock it is, I have no idea. Don't even know if it's true.

If it were my garage I'd insulate it AND sheetrock it all the way around using a double layer of sheetrock between the garage and the dwelling for fire retardation. As I recall it's required in Callyfornee.

My garage is NOT insulated but is finished on all the walls and ceiling with masonite type siding. It's colder than a witche's tit out there right now. I wish it was heated and insulated. Maybe someday we'll pull it down and do just that.

You don't necessarily need to pull it down. In my house, I was renovating and insulating the walls in the living room. I briefly thought of drilling holes and blowing insulation, but eventually decided I couldn't stand the wall material and pulled it down and hung drywall.

If it had been a garage, I'd have just drilled and blown the insulation in.

"Tanus" wrote You don't necessarily need to pull it down. In my house, I was renovating and insulating the walls in the living room. I briefly thought of drilling holes and blowing insulation, but eventually decided I couldn't stand the wall material and pulled it down and hung drywall.

If it had been a garage, I'd have just drilled and blown the insulation in.

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