thinking of insulating my 'tractor shed'

I store my tractors (and my vehicles) in a detached 35x50x15 ft concrete block garage.

I have more than enough heat to cook you on a cold winters day, but with natural gas even, it still costs me between 125-175/month to heat this beast.

I've got a new 250k btu gas heater (80% efficiency). ceiling is insulated with probably R-25 total. nothing on the walls right now insulation wise.

First and foremost- I do not want to add studs to the walls and frame them out.

Now I'm thinking foam insulation board glued to the block. Now I can easily do the upper half of the ceiling, but the bottom half has all the utilities run on it, so it would be much harder to do. I'm figuring I can easily do the top half all the way around in a Saturday. Then I can slowly work on insulating the lower half where I can as time allows. I may have to leave certain sections empty as there would be too many utilities.

So, if before winter I can only get the top half of the garage done, will I still see benefits? Or I am wasting my time if I leave the bottom open for now?

I would insulate as much as you can from the top down, I think I would use 2 inch blue foam with steel liner panel over it. Also can you blow some more in the attic, R25 isn't much by today's standards.

Any amount of insulation helps but that in highest part of ceiling helps most. Do a liitle research (ask insulation manufactures)leaving a void between wall insulation and block wall. That is possible useing lathes fastened to block useing air nailer. There are some inexpensive diy passive solar plans on the net that will supliment heat.

Guys here spray foam directly on to the tin of their steel buildings.Seems to work well.

If you have it spray foamed, you could tape off your receptacles etc. I'm assuming your utilities are in conduit, so you could just spray right over them
Pete

Main reason for insulation board vs spray foam was:
1- cost
2- DIY factor

like I said I can do the top half all the way around in a day for probably $700. that would get me R-5 foam board. which I know isn't great, but going from maybe R-1 block to R-5 would have to help a lot. one quote I saw online for spray foam was like $3000. plus all the "stuff" I have around the walls on my garage is just too much to move to have a professional spray it.

I figure I can glue the sheeting to the walls, use a couple nails to hold it till it dries. maybe even install a ceiling fan to help push the heat back down.

Edit to add: The actual insulation I am looking at has an R value of 6.5. also I would probably screw it to the walls rather than glue, this way its removable if ever needed.

One of my retired co-worker's has a large metal building and he had foam insulation installed. It was very comfortable inside when it was cold outside. He had a fuel oil furnace for heat. Hal

The best solution would be to insulate the OUTSIDE -keeping the block walls as heated mass. Downside of course is protecting the styro. I think there is a product made for this application, but is probly spendy. HTH

I have a little bit of difficulty visualizing the problem with the lower part and utilities problem. Is your objective to reduce rusting of the equipment or to make if comfortable to be in the garage at all times?

One thing is certain. It is the rate of temperature change and air exchange that causes rust on iron and steel especially when there is high humidity. I have seen heavier rust on equipment under an open pole barn than equipment left where the sun could warm it more quickly. If your building is enclosed where the air does not exchange much and there is sufficient insulation to keep the temperature of heavy metal masses above the dew point it should reduce rust formation.

If your natural gas heat is direct the water vapor produced by combustion would add to the problem by making the humidity higher inside than outside. I would think that you have a furnace with a heat exchanger that vents the burned gas out a flue, but I can't tell from the post.

My shop and house are both insulated similarly to what you want to do. We used something called "Hi-R"? Polyisocyanurate maybe? Then you could get it with foil, or fiber/paper backing. As I recall 2" = R14. The ceiling in my shop IS that stuff screwed up to the trusses with long sheet rock type screws and big flat washers. I believe the washers were something used for roll roofing? Where we wanted to put it up against a block wall we used concrete "tapcon" screws and the same washers. Maybe used construction adhesive too, I can't remember. It's been over 20 years and it has done well.

(quoted from post at 12:36:21 09/14/15) I have a little bit of difficulty visualizing the problem with the lower part and utilities problem. Is your objective to reduce rusting of the equipment or to make if comfortable to be in the garage at all times?

One thing is certain. It is the rate of temperature change and air exchange that causes rust on iron and steel especially when there is high humidity. I have seen heavier rust on equipment under an open pole barn than equipment left where the sun could warm it more quickly. If your building is enclosed where the air does not exchange much and there is sufficient insulation to keep the temperature of heavy metal masses above the dew point it should reduce rust formation.

If your natural gas heat is direct the water vapor produced by combustion would add to the problem by making the humidity higher inside than outside. I would think that you have a furnace with a heat exchanger that vents the burned gas out a flue, but I can't tell from the post.

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my goal is actually neither. I don't have rust issues, and I have lots of furnace. My goal is to reduce my utility cost by insulating.

as for the bottom half of the garage, while its not impossible to insulate it, it would be very time consuming. Like I said for one all my utiliites- gas, water, electric, and my shop airlines- are all mounted on the block. Second, major items like air hose reels, regulators, etc are mounted to the block.

So the majority of the top half of the garage I can slap a 4x8 sheet against the block and secure it. where as the lower 7' I will likely be piecing most of it in using much smaller sections. not sure I am going to have that much time in the next few months to spend a couple days doing that. which is why I asked if just doing the top 8 ft would be beneficial

(quoted from post at 13:13:27 09/14/15) My shop and house are both insulated similarly to what you want to do. We used something called "Hi-R"? Polyisocyanurate maybe? Then you could get it with foil, or fiber/paper backing. As I recall 2" = R14. The ceiling in my shop IS that stuff screwed up to the trusses with long sheet rock type screws and big flat washers. I believe the washers were something used for roll roofing? Where we wanted to put it up against a block wall we used concrete "tapcon" screws and the same washers. Maybe used construction adhesive too, I can't remember. It's been over 20 years and it has done well.

Click to expand...

thanks bob that's exactly what im looking to do. you're further north than I am too

Interesting read:
Does Your Spray Foam Insulation Need a Thermal or Ignition Barrier?
thermal/ignition barrier

(quoted from post at 09:27:50 09/14/15) The best solution would be to insulate the OUTSIDE -keeping the block walls as heated mass. Downside of course is protecting the styro. I think there is a product made for this application, but is probly spendy. HTH

Click to expand...

A friend built a new building for his his machine business about 25 years ago with foam over the outsides of the walls. It is covered with parging that looks like stucco, but it contains fiberglass fiber for added strength. They attached something like expanded metal over the foam to hold the stucco. It looks as good now as the day it was put up.

We do quite a lot of commercial building and we use Z furring for foam board. Hilti or tapcon the
furring to the wall 16 or 24 on center. Then you can attach any finish you want to the Z furring. Here's
a site if you want to look them up.
Z furring

I would use what foam insulation you have chosen down as far as possible. THEN......you could space out each utility with a 2/4 mounted behind to the block wall, insulate right up to the straight edge of the 2/4 & paint to match.

Russ from MN said it well in my mind. Just remember trapped air insulates well, so as you put blue foam up make sure it adheres to the wall well and does not leave an air gap where air can flow.

A block wall is not even a good wind break insulation/thermo wise it is so porous. Be opportunistic like Russ said, cover what is easy first. e.g. maximize sq. ft. per hour of your time. However, in the long run cover it all.

There are two things that make your shop feel comfortable, radiant and convective heat. Convective is what you feel from the heated air from your furnace. Radiant is what radiates from your block walls. In the winter those block walls make you feel cold even though the air is warm. Once you get that block covered, you sure will notice a difference and feel warmer at cooler air temperatures, more savings.

If you do consider a spray foam at all keep in mind there are open cell foams, e.g. the bead board, and closed cell foams, e.g. the blue DuPont Foam. The closed cell foams also act as a moisture barrier. Yes, I know I am mixing my examples here, spray foam vs foam board. I just don't know what examples are in the spray foam world. My 30ftx72ftx11ft shed was completely sprayed with a closed foam, 2". It is so tight. I put 6 mil poly under the concrete. The shed is so tight I can easily keep it at 50% humidity with a single dehumidifier here in the Wisconsin humidity. I lined my shed with white tin.

Enough for now.

Paul