Insulation question for cold-weather home owners.

[Ferocious]

I have an attached garage that is not insulated.

It is also unheated......so would it still make sense to insulate it anyways?

 

[rh71]

Sure it would... I don't know how much insulation costs, but it absolutely cannot hurt...

 

[Ferocious]

Ok.

The confusion I have is if insulation is good for slowing down heat loss.....but the garage is unheated.....wouldn't it be a waste?

(Wouldn't a totally insulated house eventually reach outside temperature if the furnace stayed off (no one lived there.))

 

[Carapace]

Originally posted by: Ferocious
Ok.

The confusion I have is if insulation is good for slowing down heat loss.....but the garage is unheated.....wouldn't it be a waste?

(Wouldn't a totally insulated house eventually reach outside temperature if the furnace stayed off (no one lived there.))

Yes, but if you never lived in your house you wouldn't worry about insulating your garage now would you? There is also heat generated from the sun. I have an insulated garage, and due to the fact that my furnace is in my garage giving off heat, my two cars are in there giving off heat, and heat collected from the sun, my garage stays fairly comfortable from day to day. Insulating cannot make up for a sub par door though.

 

[dullard]

I'm having difficulty understanding why you want to insulate the garage. Since the garage is unheated and attached, then you should already have a lot of insulation on the wall between the house and the garage. If you don't have insulation there, then insulate it as soon as possible since you are losing a ton of money out that wall. The other garage walls have very little reason to be insulated - you are right that in most cases it would be a waste. I can picture a few extreme cases (like if you open the door from your gargae to the house and leave it open) but for most uses I cannot picture any reason to insulate the whole garage. Can you provide us reasons why you are considering it?

 

[Maetryx]

In Alaska, you can have an overnight low of -10, and a midday temperatur of +10. If the garage achieves equilibrium, it will at *least* be at 0 in the mornings instead of -10... assuming you have some insulation on it. In truth, the unheated garage I had one time stayed about 20°F warmer than the outside temps.... a big difference in Alaska.

 

[RayH]

I would just make sure that the walls between the house and garage are insulated as well as having a good seal on the door from the house into the garage.

 

[Carapace]

Originally posted by: dullard
I'm having difficulty understanding why you want to insulate the garage. Since the garage is unheated and attached, then you should already have a lot of insulation on the wall between the house and the garage. If you don't have insulation there, then insulate it as soon as possible since you are losing a ton of money out that wall. The other garage walls have very little reason to be insulated - you are right that in most cases it would be a waste. I can picture a few extreme cases (like if you open the door from your gargae to the house and leave it open) but for most uses I cannot picture any reason to insulate the whole garage. Can you provide us reasons why you are considering it?

In my case it was:

My need to work in the garage.
Insulation is not that expensive, it's easy and quick to install.
If your furnace is in the garage, it will operate more efficiently.
If your water heater is in the garage, it will operate more efficiently.
The luxury of getting in a warm car.
Not ruining some of the electronics I store out there.

 

[dullard]

Originally posted by: Carapace
My need to work in the garage.
Insulation is not that expensive, it's easy and quick to install.
If your furnace is in the garage, it will operate more efficiently.
If your water heater is in the garage, it will operate more efficiently.
The luxury of getting in a warm car.
Not ruining some of the electronics I store out there.

Your first three are unusual circumstances (I've personally never seen a furnace or water heater in a garage - but that is probably since I come from an area where everyone has basements). And yes with unusual circumstances there are reasons. The average garage without insulation is 6°F hotter than outside. I don't know exactly how much an insulated garage will help. Probably the 20°F Maetryx posted is in unusual circumstances - I'd expect 10°F to 12°F to be typical. The improvement from 6°F is not worth the cost and effort for many people (and added property taxes if you get appraised). Otherwise all garages would be insulated.

 

There isn't much use in insulating the garage unless you plan on spending a lot of time in there.

 

[Zorba]

Go for it. My friend has a massive Barn, that he and used to spend the night at a lot in the winter. When we first started going out there there was no insulation and we would about freeze to death at night. Then his dad decided to go ahead and put up insulation and dry wall, never had a problem with it getting to cold at night again. And this was with no heater, or anything.