Shop Insulation....Cinder Block Wall

[tlspeed1]

All I am new here, but love the wealth of information. Thanks for the efforts! For my first post, I am going to dive right into it.

I have searched high and low for options and opinions to insulate my new shop, specifically the cinder block wall.

The building is 40x28. It has 10ft tall 12" wide cinder block wall on two edges in which about 70% of the wall is insulated on the exterior with foam board and back filled by dirt. If you can see the pictures below, the top 2 or 3 rows of block are exposed and on the one end, most of the block is exposed.

[/url]IMG_20150708_114443413 by tlspeed1, on Flickr[/IMG]

[/url]IMG_20150708_114422524 by tlspeed1, on Flickr[/IMG]

[/url]IMG_20150917_063916946 by tlspeed1, on Flickr[/IMG]


My question or more looking for opinions on the subject matter. I live in midwest Wisconsin. The average temperature from November to March is about 20 degrees F. I plan on heating the shop all winter with a programmable T-stat going down to 45 or 50 when not in use.

So some options I thought of. With Option 2 and 3, I would sheet the wall with OSB.

Option 1: Leave it.... I was told 12" wide block is around R-5. In this thought process the warmth of the shop will heat the block up, the block will then retain the heat. My concern is the transfer of heat in the areas that are not back filled with dirt will cause them to be frosty.

Option 2: Use 2x2s and the pink owens corning foam board to adding an R-7 to the existing 5. This provides thermal barrier between the warm shop air and wall. This method would be the quickest way as I wouldn't have to build walls, but the cost of the foam board is about $.75 a sq foot.

Option 3: Frame up another wall and lay in vapor barrier and standard fiberglass insulation adding an R-13 to the existing 5.

I estimate Options 2 and 3 being very similar in cost due to the low cost of fiberglass insulation. Obviously the higher the R value the better, so one would say insulate the best you can, so I am leaning towards framing up walls, but would like to hear the input of the GJ

Any help or input appreciated.

 

[slickgt1]

Frame up walls, about an inch or so away from the wall. Spray foam. This would probably be most expensive, but best return the longer you keep the shop.

 

[tlspeed1]

Is spray foam really worth the extra cost on the block wall. It is already sealed from drafts, which in my mind is where spray foam is the most beneficial. I quoted spray foam for the attic of the garage because there is a loft. It is about $1 a board ft.

 

[kbs2244]

I would wait and go through at least one winter.
This will show you any real problems vs. imagined ones.
If you want to go ahead, I would suggest foam board under more siding.
No need for OSB.
Just vertical nailers for the siding.

 

[buddyboy]

since it's already got insulation on the outside I would investigate a way to use rigid foam on the exposed blocks and cover it with stucco or aluminum flashing

 

[willymakeit]

Before you seal up with insulation, check for moisture migration. It may just be the photo but the dark color makes me think of moisture migration which leads to mold.

 

[tlspeed1]

I would wait and go through at least one winter.
This will show you any real problems vs. imagined ones.
If you want to go ahead, I would suggest foam board under more siding.
No need for OSB.
Just vertical nailers for the siding.

I have considered waiting, but I would like to get it wired. If I waited, I would have to leave two walls bare.

since it's already got insulation on the outside I would investigate a way to use rigid foam on the exposed blocks and cover it with stucco or aluminum flashing

Never considered this.

Before you seal up with insulation, check for moisture migration. It may just be the photo but the dark color makes me think of moisture migration which leads to mold.

Well the one exterior photo was taken when it was raining. In fact it just rained excessively here to the point where it washed part of my driveway pretty bad, but yet the garage was still dry as a bone. I see what you mean of the dark colors though. The top two rows of blocks are different styles than the rest. They have a rough finish to them for a more aesthetic pleasing look. Also through out the wall there are some blocks that are just a darker shade of color.

 

[tms0425]

I used InsoFast (R10 on mine and am very happy with it. Took me about a day and a half by myself. Studs are plastic and they just glue on the wall. Lightweight and easy to do in one shot.

www.insofast.com

http://www.garagejournal.com/forum/showthread.php?p=4499867&highlight=insofast#post4499867

 

[DTE]

I am in the process of building a 26 x 30 block building and this company here quoted me a price of one thousand dollars to foam the walls. I am still considering it Just haven't gotten to that point yet..http://www.core-fill500.com/application.htm

 

[NUTTSGT]

Option 1: Leave it.... I was told 12" wide block is around R-5. In this thought process the warmth of the shop will heat the block up, the block will then retain the heat. My concern is the transfer of heat in the areas that are not back filled with dirt will cause them to be frosty.

I'd venture to say whoever told that tidbit about a CMU being an R value of 5 was uninformed or feeding you a line. I'd guess more like a R-2, give or take a little bit. During the Winter, that block will never be warm but cool to the touch, which tells you that it is sucking the heat out of your garage.

What worked for me was tapconning some 2x4s falt against the wall, filling the gap between them with foam board and covering with OSB. Your R-value will depend on which type of foam board you choose to use.

If you can ante up for the spray foam, that would cost more in the beginning but pay for it's self over the coming years.


I'd also get more of that outside wall covered with some insulation and siding.

 

[Diesel Dan]

There is a 40x60x14 all block (12" blocks IIRC) garage near me that is 40+ years old.
Talked with the owner and the walls are insulated with a loose fill type of insulation with concrete exposed inside/out. He said it heats very easily in the winter and stays cool in the summer.

The floor is not insulated either and the exterior is painted a plain white to seal the blocks.
You could use a clear sealer on the exterior to keep the blocks from absorbing water.

 

[JCQuick]

My house has the core filled walls it really helps. I was just at a home and garden show and the foam insulation guys were every where.I'm considering it for my new shop.

 

[tlspeed1]

I'd venture to say whoever told that tidbit about a CMU being an R value of 5 was uninformed or feeding you a line. I'd guess more like a R-2, give or take a little bit. During the Winter, that block will never be warm but cool to the touch, which tells you that it is sucking the heat out of your garage.

What worked for me was tapconning some 2x4s falt against the wall, filling the gap between them with foam board and covering with OSB. Your R-value will depend on which type of foam board you choose to use.

If you can ante up for the spray foam, that would cost more in the beginning but pay for it's self over the coming years.


I'd also get more of that outside wall covered with some insulation and siding.

Yeah I mis-read what the R-value of the blocks were and you are correct.
I am leaning towards using 2" metal Z-furring channels and 2" foam on the inside then sheeting. I think I will plan on finishing the exterior with foam and flashing as well.