Insulating a 30 x 30 Block Garage

[Ironworx]

I ha ve a detached 30' x 30' (outside dimensions)8" block garage with 2"x4" wood truss roof. Inside dimensions are 28'-9" x 28'-9". Top of the block is 9'-7" (eave height) and peak height is 14'-10". The garage is not insulated whatsoever. I have two uninsulated aluminum panel overhead doors, one regular access door and 3 single pane standard windows (cheap...mainly to keep the wind and rain out). I do not have a ceiling. It is also equipped with a 200 amp eletrical service.

As you can see by the attached photos, I presently have two sources of heat I can use. The first and present source is a double barrel wood stove, which can be quite cumbersome to fire up all the time and wait for a couple of hours to warm up the garage. The second source could be a Hastings fan forced natural gas (Model F120X) heater rated at 120,000 bto maximum input and 96,000 btu output.

I would like to be able to work in the garage at least 2-3 hours per night and at least 8 hours on Saturdays and Sundays.

I have not vented nor fired up the Hasting Unit. Just mounted it on the bottom of hte roof trusses. I received this in a barter situation...took it to the car wash and cleaned it up. Looks brand new after the wash.

I would like some advice on the most econimical way of insulating the garage (and addition of a ceiling if needed) so as to best utilize the Hastings Gas Fired Unit. It would be really nice to set up the controls so that I can just walk in and flip a switch and prepare to get something done.

[walrus]

Where are you located? A ceiling with some blown in cellulose or fiberglass is probably going to give the biggest bang for your bucks. But if you are in a cold clime your still going to wasting alot fo heat with those windows and garage doors. Is the building sided or is the out side block also

[HoosierBuddy]

I think you have 2 choices,

Fir out the inside and put in fiberglass.

Fir out the outside, put in 2" of polystyrene, and put siding over the top of it. I did that with a commercial space using metal siding and it turned out nicely, but you only end up with R5.

In either case you need to replace your doors with insulated doors and any windows as well.

Economical? If you want economical...I'd recommend procuring a double barrel wood stove.

Wait...you already have that.

Seriously though...if you're going to be paying for your energy, and heating it everyday, you simply must insulate the thing properly. It needs a ceiling and insulation above that too.

Phil

[Ironworx]

Thanks for your advice guys. I'm located in middle Tennessee. The exterior is also block with a couple coats of Kilz (for concrete application). If I were to install a ceiling, I would probably use 1/4" OSB (about $6.00/sheet) and seal the joints. One problem is, I do store things up in the roof trusses. Due to the fact that the roof trusses are only 3-1/2", I won't get quite the R value I would like but, anything would be better than nothing.

[D.J.]

You didn't say what the oc of the rafters are but you could consider putting in a pull down attic stairs set and at minimum fiberglass batts in the ceiling. A + 1 on the firing out of the blocks and installing fiberglass bats in the walls. I would even consider to attempt a 6" insulation in both the walls and ceiling!
Just my $ .02
________
Voyeur College

[Kevin54]

I would probably use 1/4" OSB (about $6.00/sheet) and seal the joints.

For strength purposes, I would use no less than 7/16" and screwed to the ceiling. OSB is cheap. Especially if storing items up above. For the walls, I would put up a vapor barrier and stud the walls and either cover with a moisture resistant drywall or OSB. Just make sure you use a treated bottom plate. Seeing that it is a block wall, you could form up a curb at the bottom, pour with concrete, then build the stud walls on top of the curb. This would keep any moisture from coming in contact with any wood. Height could be what ever you wanted. Just use a bonderizer before you poured the new curb.

[Charles (in GA)]

Rigid foam board (polystyrene?) fitted into the metal garage doors would probably help them immensely.

Charles

[Phuckin' Jim]

I would insulate the exterior surfaces of the garage, and paint the interior. This way you have several tons of concrete inside the building envelope to act as heat storage.
Also, you won't lose any interior space in the garage. Sheet the ceiling with osb after putting vapour barrier (if needed), then insulate w/ fiberglass or cellulose.
Getting rid of the barrel stove will also free up some valuable floor space. You can use that space to store some of the things you had up in the trusses.

[Nealcrenshaw]

Block is a good insulator,find out how much it will cost to run the gas unit a month it might not be that bad if you're only using it a few hours a day.

No doubt insulation will help though.

[Ironworx]

I really do appreciate the advice. It's been very helpful. What a great website!

[neverenoughtools]

Originally Posted by D.J.

You didn't say what the oc of the rafters are but you could consider putting in a pull down attic stairs set and at minimum fiberglass batts in the ceiling. A + 1 on the firing out of the blocks and installing fiberglass bats in the walls. I would even consider to attempt a 6" insulation in both the walls and ceiling!
Just my $ .02

x2

[jklingel]

As always, the FIRST thing you need is a heat-loss analysis, IMO. Find out how bad the heat loss will be doing nothing (I suspect VERY BAD) and then look at the cost of various "fixes", savings/yr and subsequent payback time. The R-value of an 8" cinder block is less than 2; pretty low. Fiberglass is about 3+/inch. In your area, R-11 (3.5" 'glass) may be the most cost effective. I am not an engineer, but the idea of putting insulation on the outside will surely delay the time to heat the place, and with on/off heating, it may be more problematic time-wise. Worry not about the 2x4s in the lid. Fill them w/ 'glass, then lay 6" 'glass batts perpendicular to them. Or, blow in something. But, insulate it well. The only time I have ever read of anyone NOT recommending a vapor barrier on the inside is if it gets real humid outside A LOT; then they put the vb on the outside. You are always going to have moisture in a heated building, so stop the moisture before it gets into the insulation and ruins/lessens the R-value. Ventilate the roof above the insulation, too; moisture will get up there, esp w/ you stairway deal. Good luck.

[BlindViper]

Most of you issue with your heat up times is the ceiling. You might be just happy with some drywall or osb on the ceiling. Since you are only in the space for a few hours a day. This will keep the heat you produce down where you are working. Instead of heating the roof, if there is a ridge vent this will help a lot.

[Ironworx]

As described earlier, the ceiling joists are 2x4's (at 2' on center) and has quite a bit of light weight storage above it. I agree with jklingel about using the R-11 (3.5" glass) at the ceiling and would love to be able to run 6" batts or blow in insulation but, I don't want to think of moving this storage down in my floor space. I intend on looking for better R value windows (3 of these) and insulate the two garage doors. I think with the size NG Heater I have and the 3.5" insulation at the ceiling, I should be able to keep it somewhat comfortable.

Also, I just finished viewing a thread where the builder used ribbed exterior grade metal for his ceiling finish. Would anyone see a problem in using this?