New Detached Garage - Insulate or no?

[sjuhawks19]

Hi, apologies if this has been answered before, I searched and couldn't find the exact question I had.

I just finished having a detached 2 car garage built (22x22) and don't plan on adding any hvac to it. It's more to house my vehicles than it is a workshop. It's a cement slab and it's finished in siding and some stone, with a gabled roof. I live in the Philadelphia area so the winters get cold, but not crazy cold for the most part. I don't mind getting into a cold car in the morning, but I really don't want to have to scrape the windshield in the morning like I would if I parked in the driveway. In my attached garage I never had to do that, but that was attached and was insulated (although not heated). To avoid that, should I insulate the walls (right now the interior is down to the studs) and ceiling? Will that make any difference if I never heat it?

Thanks!

 

[kd3pc]

no insulation will make a difference, just how much is the question.

My 24x24, well insulated - seldom gets below the upper 30's even when it is near 10 outside for weeks at a time and windy.

not too cold to work, except picking up the tools, I don't use gloves, and the tools are ice.

 

[BillK]

My 24 x 24 detached is not insulated or finished inside and I have never seen frost on anything here in Maryland. It gets too chilly to work out there but as far as anything getting on the car it does not happen.

 

[rct]

Our attached 20x30 garage was insulated and drywalled. It is not heated, but mostly stays above freezing all winter from engine heat. I think it also helps keep it cooler in summer. Fiberglass batts are usually cheap so it's a worthwhile upgrade even without hvac.

 

[BillK]

Just want to add that if you are going to finish the interior then I would definitely insulate it while you have the chance.

 

[The Cobbler]

biggest benefit of insulation in a non heated building is it will stay cooler in the summer

 

[stm317]

Insulation is pretty much always better than no insulation. It will stay warmer in the winter, and cooler in the summer.

 

[ripperd]

Yes, insulate it!

In the winter, there is a very big benefit as pulling in a hot car will bring some heat into the building. With the insulation, it will retain that heat much better, keeping it warmer and helping to melt the snow/ice/frost.


The only downside I have seen so far is the same effect in the summer: Pulling hot cars into the garage means the garage gains significant heat. Because of the insulation, this heat doesn't dissipate overnight when it is cooler outside. So the garage ends up running warmer than it would without insulation in the summer. However, if you are not pulling hot cars in, the garage will indeed stay cooler during the summer with insulation. We are in the process of moving so for the last two weeks we have not had our daily drivers in the garage as we use the attached+insulated garage as a workshop/storage. The garage has been significantly cooler than when we were pulling DD's in and out every day!

 

[Stuart in MN]

I've never had to scrape the windshield on my car in my uninsulated garage here in Minnesota, unless you get some weird moisture patterns in PA I doubt you will either. It will stay a little warmer inside the garage than outside even without insulation, and adding insulation will keep it a little warmer yet (as mentioned above, the heat from your car won't dissipate as fast.)

 

[Bretny]

Insulate it!..as you will never say to your self..damn i wish my garage was colder in the winter and warmer in the summer.
Sooner or later you may want to paint or do something out there and a small electric heater might be enough. Bit never will with no insulation

 

[NUTTSGT]

. . .. . To avoid that, should I insulate the walls (right now the interior is down to the studs) and ceiling? Will that make any difference if I never heat it?

Thanks!

Never say never. Yes insulate it. If you finish off the inside without insulating it, when that day comes, you'll be cussing yourself for not doing it.

Remember that insulation is an investment. It'll continually pay for itself every time you fire up the heater or AC unit, even at this time when you on doing neither.

 

[bobbyjean]

would you be finishing the interior now? if not you could just wait and see
how it goes,if you do decide to insulate check out some you tube video's about
air sealing......helped me out in my garage...then i realized that my house probably needs it more....still on my to do list

 

[sjuhawks19]

I appreciate all of the thoughtful responses, thank you all. I do plan finishing the interior eventually, probably in stages. The first thing I was going to do before the winter was put a slat wall along the back of the garage. So that's why I was asking, it sounds like I should insulate that and then keep insulating as I finish the other walls. I wasn't planning on putting a real ceiling in though, I kind of like the exposed beams look. If I don't insulate the roof as a result of that, is the insulation on the walls even worth it?

 

[NUTTSGT]

The insulation on the walls will help but you'll still lose heat out the attic vents / soffit /ridge / gable.

If you put a ceiling in and create an attic space, it'll help keep it cooler in the Summer and warmer in the Winter.

Either way, put the insulation in the walls.

 

[kwschumm]

Built a house and decided to cheap out by not insulating the garage. I regretted it every summer and winter. Insulate it.

 

[PWilks]

Insulation on 440 sqft around here, even with 12’ ceilings and like r40 in the ceiling is only ~$500 with HD prices. Heat rises.. will insulating the walls help? A little. Will it make a large difference without insulating the ceiling? Probably not.

Aside from your aesthetics of a open beam ceiling, chances are you can’t store heavy stuff up there anyway (I’m going to assume you have common trusses with a 2x4 bottom chord), as these were not designed for a live load on the bottom chord. Finished ceiling are the way to go, and anything you can fit up an attic access ladder is probably within reason to store there (spread over many trusses via a sheet of plywood)

I suggest you finish the ceiling.

 

[LaneRover]

I agree that insulating the garage now is a good thing especially since you plan on finishing it off later.

If you can't afford spray foam (or think why spend the money if you weren't sure about insulating in the first place) I would look at Rockwool insulation. It doesn't soak up water (not saying it can't get wet but it won't act like a wick) It doesn't go in quite as quickly as fiberglass but it also isn't as ichy.

and yes also insulate the ceiling or roof (don't know your construction)

 

[nadogail]

Any insulation is better than no insulation.