What do I need to insulate my garage?

[Jumpem]

Is it as simple as getting rolls of fiberglass insulation? Are there any better materials? Does drywall matter for anything other than providing a finished look?

My goal is to keep snow and ice from my car from freezing on the floor.



The garage should be in the garage...

AT Moderator
Bartman39

 

[Charmonium]

If you have a detached garage, I don't think any amount of insulation is going to help. So I assume you're talking about an attached garage.

I'd start with the attic and have some insulation blown in. Recycled, shredded paper that's made fluffy like goose down is pretty cheap and effective. It takes maybe a couple of hours to do and you don't have to worry about prickly fiberglass fibers getting everywhere - although most of the insulation now I think is in sealed packaging.

If you're in a very cold climate like say New England or southern Canada, that might not be enough. But otherwise, heat leakage from your home might keep the garage above freezing.

 

[DaTT]

First off, how old is your garage door and what is the R value of it? Is it sealed at the opening (ie no small gaps around the garage door).

The only walls required to be insulated would be those that are considered "interior" walls (walls that are shared with the inside of your house)

I'm not really sure insulating the whole garage will provide a huge benefit unless you actually heat your garage as insulation is desgned to keep heat/cool within its limits.

On to your question though, if you want to go ahead, you'll need insulation and vapour barrier. Drywall is just to provide a finish look as the R value is very low. It won't be required if you properly seal the vapour barrier.

Edit: Drywall is also use as a fire separation on the above mentioned Interior Walls. That is why most attached garages are partially drywalled and insulated.

 

[Jumpem]

If you have a detached garage, I don't think any amount of insulation is going to help. So I assume you're talking about an attached garage.

I'd start with the attic and have some insulation blown in. Recycled, shredded paper that's made fluffy like goose down is pretty cheap and effective. It takes maybe a couple of hours to do and you don't have to worry about prickly fiberglass fibers getting everywhere - although most of the insulation now I think is in sealed packaging.

If you're in a very cold climate like say New England or southern Canada, that might not be enough. But otherwise, heat leakage from your home might keep the garage above freezing.

I am in central NY. We get cold temperatures and a lot of snow. My garage is attached on the front of the house, with only the back wall (already finished) connecting to the house.

My previous house had an attached, and finished, garage that was under the house. So the top of the garage and one of the long walls connected to heated spaces. That was enough to keep the floors from freezing.

 

[Jumpem]

First off, how old is your garage door and what is the R value of it? Is it sealed at the opening (ie no small gaps around the garage door).

The only walls required to be insulated would be those that are considered "interior" walls (walls that are shared with the inside of your house)

I'm not really sure insulating the whole garage will provide a huge benefit unless you actually heat your garage as insulation is desgned to keep heat/cool within its limits.

On to your question though, if you want to go ahead, you'll need insulation and vapour barrier. Drywall is just to provide a finish look as the R value is very low. It won't be required if you properly seal the vapour barrier.

Edit: Drywall is also use as a fire separation on the above mentioned Interior Walls. That is why most attached garages are partially drywalled and insulated.

The garage door is brand new. It is R 13.45. It has a good seal along the bottom of the floor.

 

[Charmonium]

My previous house had an attached, and finished, garage that was under the house. So the top of the garage and one of the long walls connected to heated spaces. That was enough to keep the floors from freezing.

That describes my situation. There are rooms over the garage and it connects to the basement. So I generally leave the cellar door open and open up a single heating vent. That's enough to make the garage almost toasty. The walls are brick and cinder block about halfway up and then wood with aluminum siding. But the garage doors leak like a sieve.

 

[yh125d]

Drywall does have some fire-resistant qualities but in practical scenarios it's not going to keep your house from burning down so I wouldn't necessarily worry about it too much. I'd bet some fiberglass would be all you need to keep it warm enough to not freeze, and I would look at putting up some pegboard or something similar up instead of or over top of your drywall.

If you find that it still freezes some of the time after insulating, a small electric heater with a thermostat set to only come on at 35 degrees or something would probably be enough to make the difference but would only come on very rarely I would think

 

[Jumpem]

Drywall does have some fire-resistant qualities but in practical scenarios it's not going to keep your house from burning down so I wouldn't necessarily worry about it too much. I'd bet some fiberglass would be all you need to keep it warm enough to not freeze, and I would look at putting up some pegboard or something similar up instead of or over top of your drywall.

If you find that it still freezes some of the time after insulating, a small electric heater with a thermostat set to only come on at 35 degrees or something would probably be enough to make the difference but would only come on very rarely I would think

I want to do something relatively cheap and see how the winter goes. Then make adjustments next year if needed.

 

[Carson Dyle]

If you don't have a source of heat in the garage, insulating isn't going to help it to be much warmer than outside, or what it would be without insulation.

 

[Charmonium]

The electric heater is a great idea. I did this with a vacant property once to keep the pipes from freezing. I put 2 small heaters upstairs and one in the basement - in case the furnace ever went out. Well, one year it did and my ass was covered.

Look for a barn heater. Check to make sure that the lowest setting isn't much above freezing. Indoor space heaters tend to have very high minimum temps, at least for what you want. You don't need the garage at 50 or 60 degrees.

Try to get one with a graduated thermostat so you can see what temp you're getting and then verify with a cheap thermometer.

It shouldn't cost too much in terms of electricity unless you get a lot of below zero days. The leakage from the house is probably going to do the heavy lifting. But you can always check your usage with a watt meter.

 

[Jumpem]

If you don't have a source of heat in the garage, insulating isn't going to help it to be much warmer than outside, or what it would be without insulation.

The finished garage at my previous house did not freeze. It had no heat source other than whatever leaked through from the heated portion of the house and radiant heat from the car engine.

 

[boomerang]

The finished garage at my previous house did not freeze. It had no heat source other than whatever leaked through from the heated portion of the house and radiant heat from the car engine.

Exactly right. Enough heat is transferred from the common wall with the house as well as the heat from the cars that my attached garage never gets below freezing even when we have occasional bouts of well below zero temps that can last for four or five days.

I think that the garage door is key in this though. It's a big opening and an uninsulated door that seals up poorly can negate any gains.

I had the garage uninsulated for many years before insulating and drywalling it and it made a huge difference. One thing I did do in conjunction with that project was putting vents under the eaves and can vents in the roof. I didn't want to seal the garage up tight and not allow for airflow through the unheated space above. As the garage is not truly heated it was probably overkill but it wasn't very costly to put in the vents and I figured better safe than sorry.

I would drywall just to protect the insulation from sagging, getting bumped into and perhaps poking holes through the paper, etc. No need to mud and tape it if you don't desire and no need to paint it. There are alternatives to drywall that would provide the same protection but the cost factor would have to be researched. You should also remember that vermin will find their way in and insulation is the kind of nesting material they really like. Probably best to keep it out of easy reach.

 

[Greenman]

Drywall does have some fire-resistant qualities but in practical scenarios it's not going to keep your house from burning down so I wouldn't necessarily worry about it too much. I'd bet some fiberglass would be all you need to keep it warm enough to not freeze, and I would look at putting up some pegboard or something similar up instead of or over top of your drywall.

If you find that it still freezes some of the time after insulating, a small electric heater with a thermostat set to only come on at 35 degrees or something would probably be enough to make the difference but would only come on very rarely I would think

Drywall has very good fire resistance, that's why it's used to build fire walls. They range from a 20 minute wall, up to several hours before burn through.

 

[WackyDan]

I have an attached garage that is insulated and has an insulated door... During protracted cold the garage gets just as cold as the outside, but I can run a couple of space heaters in there and within 1/2 hour or so it is comfortable enough to work on stuff out there.

 

[desy]

My insulated garage w shared wall and drywall has never been below 0F even if its -40F outside.
However I prefer it cold because the freeze/thaw cycle promotes rust so I have never considered heating it although its setup to do so

 

[JEDIYoda]

insulation is a good start...

 

[Leros]

I insulated my garage door with these styrofoam panels: https://www.amazon.com/gp/product/B008OPLHVE/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

It made a huge difference. You could maybe save some money buy just buying 3/4" styrofoam in 4'x8' sheets from the big box store. The advantage of the panels I bought is that they have a plastic sheet on one side to make them more durable.

 

[Slacker]

Find out what this guy did, then do more...