Heat Loss

[1938flatty]

Just finished insulating my garage, about to turn on my radiant slab heat. My question is do you think I will loose a lot of heat with the space not drywalled.

R-19 in the walls R-30 in the ceiling. Thanks

 

[Charles (in GA)]

Insulation with the kraft paper showing, stapled to the studs? Naw, you will lose some, but not that much. Its going to take several days to bring the slab up to temp anyhow.

Gotta have it nice and warm in there for the sheetrocking and mudding.

Charles

 

[Falcon67]

What Charles said - but you might be amazed at how much better it all works once you get the ceiling sealed up. My old shop was just batts stapled to the walls/ceiling and it did very well.

 

[1938flatty]

Thanks for the replies!!

 

[wedge40]

We would love to see your set up if you got the time to post a few photos.

Wedge

 

[1938flatty]

As soon as I figure out how to post some photos I will.

 

[Gary S]

1/2" drywall has an R value of R0.45

So, if you cover your R19 insulation with 1/2" drywall, it becomes R19.45

Not a noticable improvement if you have the insulation well installed with no gaps.

 

[burleyfarm]

Just finished insulating my garage, about to turn on my radiant slab heat. My question is do you think I will loose a lot of heat with the space not drywalled.

R-19 in the walls R-30 in the ceiling. Thanks

Just make sure you have the vapor barrier installed.

Heck, just order the drywall and hang it. You've got lots of time before it gets really cold and you and your wife could hang it together.

 

[DPelletier]

1/2" drywall has an R value of R0.45

So, if you cover your R19 insulation with 1/2" drywall, it becomes R19.45

Not a noticable improvement if you have the insulation well installed with no gaps.

Yep, that's it in a nutshell. Make sure the vapor barrier is installed


Dave

 

[burleyfarm]

Got that picture posting thing figured out yet? We could use some pictures of your system and that sprayed foam you installed in the attic.

 

[Highbeam]

It's not the R-value of the sheetrock that will make the difference, it is the superior air seal that keeps the hot air from just walking out of the space. If you had a sealed sheet of plastic on the inside of all of that insulation I would propose nearly zero improvement from the sheetrock.

Either way, with radiant slab heat, I would fire it up after the insulation is in.

 

[pseudorealityx]

Any time you can change materials, there's an added insulation above and beyond the actual insulation value of the material. There is an inherent inefficiency of transferring the energy between materials.

 

[theoldwizard1]

It's not the R-value of the sheetrock that will make the difference, it is the superior air seal that keeps the hot air from just walking out of the space. If you had a sealed sheet of plastic on the inside of all of that insulation I would propose nearly zero improvement from the sheetrock.

Any time you can change materials, there's an added insulation above and beyond the actual insulation value of the material. There is an inherent inefficiency of transferring the energy between materials.

Both statements are accurate ! The second one usually works against you, but in this case it is working for you. Heat spreaders can work against you if the heat sink is

1. not large enough
2. has a lower thermal coefficient (heat does not flow well from aluminum to steel)
3. there is dirt between the heat source and sink
4. there is insufficient contact pressure between the source and sink

 

[Fun pain]

I don't know what part of michigan you live in but a vapor barrier might not be a good Idea, as some have mentioned....


example:
http://garagejournal.com/forum/showt...5945&showall=1

If you are far north and you probably, will be fine. unless you move alot of cars in and out, then you will get rusty tools and cars.... unless you exhaust the moisture somewhere.

Reasons:
post 9 of this topic explains pretty well.
http://garagejournal.com/forum/showthread.php?t=228691

The kraft face should be enough of a vapor retarder to be just fine for a Garage with Radiant.