Insulating the garage ceiling

[moparguy01]

For those of you who have insulated your garage ceilings, what R value insulation did you use and how big of a difference did it make for heating it up?

I've got 1020 sq. ft. of garage, the walls are R15 insulated and I'm in the process of putting up OSB on the walls and ceiling. (I checked and it passed local codes and I got a screaming deal on enough to do it all) Now I won't be out there all the time, but pretty frequently, probably 3 days a week or so. I'm looking into the cellulose blow in,mostly due to the cost. I was thinking somewhere between a R-22 and a R-30 value. For now all i have for the garage heater is one of the round construction heaters, a 100k btu unit which runs off a propane tank.

Any thoughts or advice?

[bakerhillpins]

I guess I wonder why you would insulate at the ceiling level and forfeit all that storage space? Why not insulate in the rafters and take advantage of the space in the trusses (assumption on my part)?

[NHCharger]

Depends on where you live. I have R-30 in the ceiling.
Here in NH any insulation is better than none.
It also makes a big difference in the summer. My garage area which is not insulated can be 10º-25º warmer than the outside temps on a sunny day. The shop will be 10º-15º cooler than the outside temp.

[moparguy01]

I'm in the frozen tundra of Minnesota. Due to the fact the rafters are built with 2x4s and have a span of 34 feet I'd rather not hang too much weight in them.

[sunfire69]

I'm at that same stage....same size garage pretty much...cost is a big factor for me....I'm going with the blown-in-cellulose...at LEAST R-30...and if I have the money I'll take it to R-45 or 50...after that weight starts to be a factor....in my last garage that was fully insulated walls R-19 ceiling R-30 it stayed above 32 in the winter...even when the outside temp was below zero and in the summer would stay 10-20 degrees cooler than the outside air...and was much slower to heat up....I never got around to heating it....

[TK73]

Thought the title said "Insulting the garage ceiling"

Need that 1st cup o coffee...

[twodko]

I had cellulose blown in the attic of my shop. Even with the moderate weather I enjoy here in NorCal it makes an huge difference. Much cooler longer in summer and is at least 30* warmer in the winter as compared to outside temps. My shop was originally a one man wood shop, my neighbors rarely heard any of the big machines running with the doors/windows closed. Lots of pluses IMO.

[Charger_Dart]

I put R-30 in my ceiling and it does a nice job handling our New England winters. As mentioned, it helps with noise reduction also.   

[NHCharger]

Sunfire. After R-40 in the ceiling the added insulation isn't worth the extra cost. The majority of heat loss in any building is the gaps in the insulation, poor seals around doors and windows, etc...

[flyinlow]

R 25 in Ohio, blown in loose fill. R20 wall .R 10 overhead door.  Garage heated to 45* as a baseline.

[sunfire69]

NHCharger your right !....if you are having someone do the work...but using the blown in cellulous and doing it yourself the extra R value is less than $100 and I'm up there anyway....and it makes me feel better...LOL...but you are correct....after R-40 or so the benefits drop off rapidly and the cost recovery starts to get drawn way out....

[Darkman]

Just be careful with the cellulose blown stuff. Although it is claimed not to catch fire, there have been many cases in Aus of houses burning down because of the blow in material and electrical fittings

[Patronus]

Make sure your lighting is IC rated before you insulate. I would recommend renting a blower and getting some help and doing it yourself. Home
Depot rents a pumper to do it, just need a hand feeding it in. Figure 12-14 inches would be R-38-R-40.. 

[flyinlow]

I tried to burn some of the blown in stuff, flame went out when I took the torch away,at least when it was new. With years of dust, the dust might keep an electrical fire  going some.   

[HPP]

I got a screaming dealing on a pile of R15, so I used it everywhere. Sure, it isn't as effective in the ceiling, but is just the garage. Its a huge improvement over nothing, and I'm not sitting out there in my scivvies watching TV, so it doesn't bother me much. However, I do have a heater I can use on those really cold days, so it balances out okay for me and was an inexpensive proposition to match our relatively mild winters.

[4aThrill]

I did my Attic with the blown insulation spent around 700 bucks with renting the blower, doing all the prep work, putting in some new wiring/ lights all myself with the assistance of the wife putting the pink insulation squares in the blower. 1800 sqft R49 thru R60 in some areas, it felt like it was snowing in there lol now the house is cool in the summer, warm in the winter. cant hear anything from outside.  with the garage i will be going with the spray in, it gets in all the cracks and crannies no mold issues, no bugs. free and clear from everything else    i got all my stuff from Lowes