Insulating Garage

[jtfoxman]

This is a little winded but I would like to give everyone enough info as possible.
I have a 24' x 16' detached a-frame garage that I was thinking of insulating. The walls, 2"x4" 16" on center, and roof joists, 2"x6" are open and the exterior is T1-11 with paper water vapor backing, so it doesn't hold heat very well. It has soffit vents all around, no ridge vent and 2 small 12"x12" vents on each end of the garage. Doors are well insulated and I will be adding storm windows. Adding insulation should be a piece of cake since all the walls and roof are open besides for some shelves and peg board. It is costing me about $2 hr to heat when I am in there so it does get costly and freezing cold in the winter. It costs me about $250 every winter to heat and it is about 10F warmer then what it is outside before I turn the heat on. I use a 60,000 BTU kerosene torpedo heater with the garage door open a few inches since I'm only in there on the weekends usually. I will be adding R13 faced insulation since I can get it cheap from a pal who has a lot of extra. I can do the whole garage for about $200.
Now the walls I know what to do with but my questions would be about the roof, electrical and the cost effectiveness. Since I have soffit vents but no ridge vent can I just put the insulation up against the roof without leaving any room for the air to circulate between the roof and insulation or do I need to add baffles between the joists for the air? The 2 vents on either side of the garage I will just cover up with sheeted insulation and remove it in the summer for some air circulation. The wiring can I just cover it or go behind it with insulation or do I have to cut the insulation around them and the outlets? And would this be cost effective or should I just leave it the way it is? I am also a little concerned about moisture build up when the heat is on since now the walls get a little bit damp if the heater runs for a long time, 4hrs or more.
Thanks for reading my post and for any help you can offer.

[pushkins]

When you add the insulation to the roof you must use baffles the entire way to keep a clear air channel from soffit to ridge, in this case you also going to have to add a ridge vent to allow the movement of air from soffit to ridge or you will end up with all sorts of roof deterioration problems.
You do not want insulation touching the roof deck.

As for the wiring question, the insulation can either be over it or tucked behind the cables, I usually run a quick knife slit part way through the insulation and encase the wires, for the outlet boxes and switch boxes just tuck the insulation behind the boxes.

You are aware that you cannot leave insulation exposed, you will need to install drywall or similar over the top. and you don't want faced insulation as you already have a vapor barrier.
Another problem you will face with exposed insulation is when you heat the garage the insulation will absorb any and all moisture, and obviously this is not a good thing.

[jtfoxman]

So I need to add a ridge vent to the roof. That just sounds like a little to much just to insulate my garage to save a little bit a money over many years. I'll just keep heating it the way I am. My roof is in pretty good shape so it sounds like a waste. I'll just keep it uninsulated until I need a new roof. I also never new I couldn't leave the insulation uncovered. Why is that?
Thanks for the info pushkins!

[mrcaptainbob]

Ridge vent

You don't need to replace the whole roof for a ridge vent. All that's needed is to remove the ridge cap shingles. Cut away the shingles and decking about two inches parallel to the ridge on both sides of the ridge. Install the ridge vent over those new slots and cover that with new shingle tabs. Very easy and relatively cheap. Part of the reason for a lot of condensate is the kerosene has a lot of moisture in it. That, along with the temperature change, adds to the condensate issue. Pushkins is right about covering the insulation. It's no good to get it wet (condensation) and must be covered with a fire proof material. Before you add the insulation to the ceiling, install those styrafoam air dams from soffit to peak. Also easy and cheap. Then install the insulation on top of that. (unfaced, as Pushkins said.) Your garage will be toasty warm after this. Sound neat. I wish I could do that in my barn/workshop.

[jtfoxman]

Is there another way I can heat the garage better without adding the insulation. As I said I don't spend much time in there and really don't want to have to cover the walls since this would most likely double or triple my cost to insulate and would take much longer to recoop the initial cost investment.
Don't really like a wood stove or coal since they take up more room and the storage of the fuel. I'm thinking propane or gas.

[doorrepairsac]

garage doors

Don't forget to get good insulated garage doors after all your hard work.

[jtfoxman]

This is getting more expensive by the minute. Not sure if it is economocal to do this.
I was also thinking my electrical in there now is run towards the top of the wall on the outside of the studs not in the wall so I would have to rewire most of it, then add sheetrock on top of that, a ridge vent along with some shingles, the insulation and the roof baffles for the insulation. This is getting expensive just not labor intensive since i have to rewire, cut the ridge vent, hang sheetrock on the roof/ceiling and tape and mud. You all have just talked me out of it. Maybe I'll just look for a cheaper way to heat it besides for kerosene which has that smell to it that clings to everything.

[mrcaptainbob]

Sheet plastic.

Okay. I can sure empathize. Sheet plastic will do quite well, then. I'm sure yhou have trusses or some form of ceiling type cross pieces, 2x4, maybe 2x6, whatever. Just staple some clear plastic to the underside of them. Light plastic like what's used for drop cloth is the cheapest, heavier sheet like 4 or 6 mil plastic sheet would do better. I hung the painter's plastic on the basement walls at a past house and the basement temp rose by four degrees. If you don't access the roof side of those rafters, then it's no big deal. Would keep TONS of heat in. Change and quick, too. And I remember from your first post about venting the fumes from the kerosene heater. Good call. I don't like the smell from them and prefer the electrics much more.

[jtfoxman]

Thanks! That is some good advice! Do I have to worry about any moisture build up on the underside of this plastic?
1 more question regarding a refrigerator I keep in the garage for my bevages and overflow from our house frig. Is there away to keep the frig from freezing up in the extreme cold? Right now when it is really cold the frig will try to kick on but shut right off. Now when the garage warms up when I have to heat on after an hour or so the frig will come on and stay on to cool down the frig. Lately I have been just turning of the frig and just storing the beverages in there since they stay cold anyway. I would like to be able to keep this frig on throughout the winter without the risk of food spoiling.

[pushkins]

If you install the plastic it will most certainly keep the heat in BUT it will also act as a hot house, it will trap moisture, you'll need a fan of some description to keep the air circulated.
For your fridge, if you don't want the issue of labor and expense to insulate and drywall the garage you could build a small room (big closet) insulated just for the fridge.

[jtfoxman]

Nice idea! I will be building a little closet for it. Thanks