Keeping a garage warm: What would you do next?

[Augusto Orosco]

After getting my Dayton G53 electric heater (http://www.sawmillcreek.org/showthread.php?t=122266) , I am now looking for further improvements in my garage insulation. I can’t tackle everything this winter due to time and money constraints, so I am looking for the best bang for my time/buck.

It's a 2 car attached garage with 8' ceilings and about 500sf of total area. The garage walls are sheetrocked, but with no insulation (with the exception of the wall that is shared with the house). The ceiling is also sheetrocked, but the attic on top is not insulated. The two garage doors span most of the longest wall and are already insulated with a 1.75” thick rigid foam in between the metal sheets (pre-installed by the manufacturer).

Last weekend, temps went down to the high 20s and the garage was about 40F (without the heater being used). I fired up the heater and had the garage at 50F in about 15 min, but after an hour, it wasn’t getting much warmer than 52. It’s good enough for me to work, but now I am getting ambitious and thinking that 55-60F would be great!

So here is what I have currently in mind:

1) Garage doors: I could add some additional insulation on top of what they already have, but it doesn’t seem like the best first thing to do.

2) I could insulate the attic with some bat insulation. It would be an easy DIY project, and for the 400sf of area, I am probably looking at something in the $300 worth of 30R insulation. I am leaning towards doing this first.

3) I could blow in some insulation through holes in the un-insulated walls (about 400sf of wall area). I have no idea how to do it myself and probably would have to hire someone. Don’t know how much that would cost either.

If you can pick only one of those 3, which one would that be? Any ideas about costs? Any other alternatives I might be missing that would make a bigger impact?

Thanks!

[Baxter Smith]

Ceiling first. Then check the seal on the weatherstripping around the garage doors. They are the biggest draft area on my shop. Maybe they can be adjusted slightly to provide a better seal. If you don't have to open both all the times, you might even consider taping the joints with some magnetic tape where the panels meet. I put some magnetic weatherstripping around mine.

Those extra 5 degrees are nice! Good Luck.

[Lee Schierer]

I would insulate the ceiling first and then the walls. Most importantly you need to get rid of air flow. Any hole to the roof area will dump heat almost as fast as you can make it. Most rental places will rent blowers for blowing in cellulose insulation. It's not my favorite material, but is probably the least cost option for your sheet rock walls. You can also get spray in foam that provides superior insulation, but the cost may be out of your budget.

If you put batts in the ceiling, wear long sleeves and tape on gloves, wear a face mask and wash up with cold water first. Make sure you don't block off the air flow from the soffets through the eaves in the ceiling with the insulation.

[Mike Cruz]

I suppose I would do 2, then 3. One without the other won't really do the trick, IMO. But then again, either will help. I think the doors would be the third on the list.

Hey, take out the insulation on the wall that is shared with the house...rob some of that heat!

[Peter Aeschliman]

Definitely the ceiling first, no question. Way more bang for your buck there.

Magnetic tape- now that's a fantastic idea! That's the major remaining area I need to address in my shop and I was struggling to come up with a way to take care of it. Thanks!

[Bob Borzelleri]

Augusto...

The first thing I would do (and actually did) is spring for this:

http://www.google.com/products/catal...wAQ#ps-sellers

I have used it for diagnosing heat loss throughout the house and the shop. It's the best option I can think of for prioritizing where to focus on heat retention/loss.

You can spend a lot on these things, but the one I refer to in the link is a good combo of fairly inexpensive and accurate.

Once you get over pointing it at the cat, the oven and boiling water, you can really get down to business and know exactly where you need to address heat loss in the garage and anywhere else. too.

...Bob

[paul cottingham]

Just out of curiosity, how much heat loss (or cold ingress) would you get from a floor deain that hooks into the perimeter drains? Would you need to do something about that?

[Augusto Orosco]

If you put batts in the ceiling, wear long sleeves and tape on gloves, wear a face mask and wash up with cold water first. Make sure you don't block off the air flow from the soffets through the eaves in the ceiling with the insulation.

One more question regarding the attic: Do I need paper faced or unfaced bats for this? The joists are around 36" on center (IIRC) and the sheetrock panels are attached to 1x2 wodden battens nailed accross the joists

[George Bregar]

One more question regarding the attic: Do I need paper faced or unfaced bats for this? The joists are around 36" on center (IIRC) and the sheetrock panels are attached to 1x2 wodden battens nailed accross the joists

I would think they are 24" OC...but yes, paper faced. I would only go a standard R19 if you are cost conscience...this isn't a living space that is heated constantly. You can always blow in later. I would also just pull off the sheetrock on the walls, use faced batts, and then rerock. Doesn't cost much for two walls, and you really need a moisture barrier. Approx cost assuming two 24' walls: Drywall $60. Wall insulation (2x4) R13 Faced= $90

[bruce buren]

ceiling, with blown in

easy diy and free machine with insulation purchase

[Eric Gustafson]

I would also just pull off the sheetrock on the walls, use faced batts, and then rerock.

If you go with the blown-in insulation, You can use it on the walls, too. You won't have to remove the sheetrock and you will save yourself a lot of time.

Drill holes at the top of each cavity with a HF hole saw large enough to get the blower nozzle in, fill the void, and replace the plugs you took out of the wall with a piece of backer board and a few drywalls screws. There may be a blocker board halfway up the wall. In this case, you have to drill two holes each cavity.

[Augusto Orosco]

If you go with the blown-in insulation, You can use it on the walls, too. You won't have to remove the sheetrock and you will save yourself a lot of time.

Drill holes at the top of each cavity with a HF hole saw large enough to get the blower nozzle in, fill the void, and replace the plugs you took out of the wall with a piece of backer board and a few drywalls screws. There may be a blocker board halfway up the wall. In this case, you have to drill two holes each cavity.

But wouldn't I need a vapor barrier for the walls? Or is that not needed in the garage?

[George Bregar]

But wouldn't I need a vapor barrier for the walls? Or is that not needed in the garage?

Yes you need a vapr barrier. Which is why just blowing in insulation is a bad idea for walls and ceilings.

[Cliff Holmes]

http://www.google.com/products/catal...wAQ#ps-sellers

+1 on the IR thermometer. The thing has so many uses around the house. And my wife uses it to get the griddle to the perfect temperature for pancakes!

Cliff

[Don Jarvie]

Ceiling - if your not going to use the attic for storage, etc use blown in. If you hope to use it then use the batts.

Blow in is messier but also cheaper.