I have a detached cinder block garage. Its been remodeled years ago with drylok primer and a color coat of paint on the walls and slat wall/cabinets in some areas. The entire 2 car garage is fairly narrow at only 20 ft, so adding framing and rigid foam has always been out of the question. When needed, I use a propane torpedo heater that works well, but often wonder if I should be insulating the ceiling rafters or inside garage door panels. Not sure if either is worthwhile if there is no insulation on the cinder block walls. Thoughts?
Detached cinder block garage
- Thread starter imgn tht
- Start date
Right now the majority of your heat loss is going straight up so insulating that will definitely help as well as insulating the garage doors. CMU does actually have a little bit of insulation value. Take a cheap laser pointer temperature gun and check the differences around the garage and you can see what the areas are coldest.
Insulation is always a good thing. Definitely insulate what you can.
I know you are avoiding it, but even 3/4" or 1" foam on the walls, good stuff not the el cheapo variety, and sheet rock the walls and you will be surprised how much it will help.
Foamular 150, 1" thick has an R5. You can glue it right to the walls, and use Tapcons and screw the sheet rock right over the foam, no furring strips required. You will only add 1-1/2" per wall, and a much warmer shop.
https://www.owenscorning.com/en-us/insulation/products/foamular-150
I know you are avoiding it, but even 3/4" or 1" foam on the walls, good stuff not the el cheapo variety, and sheet rock the walls and you will be surprised how much it will help.
Foamular 150, 1" thick has an R5. You can glue it right to the walls, and use Tapcons and screw the sheet rock right over the foam, no furring strips required. You will only add 1-1/2" per wall, and a much warmer shop.
https://www.owenscorning.com/en-us/insulation/products/foamular-150
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I didn't know what CMU is...but google searches suggest it is the same thing. Garage was built in the 50's.
Concrete masonry unit. Cinder blocks haven't been made since around WW2. It was waste from burning coal.
kaymccampbell
Well-known member
Since heat rises, insulate the ceiling first. Then the door. It'll be much nicer in there.
TomC750
Well-known member
I will agree with the value of even a small amount of insulation. We own a small rental house, totally block construction. All the rooms except one have paneling over furring strips. That one room without is noticeably colder than the rest. I realized this about the time I finished installing quarter round against the uneven baseboard! Now I am wishing I had insulated.
These days most high performing buildings all have exterior insulation. If the exterior of your detached garage is unfinished block I would consider at least 2" foam or mineral wool, then furring strips, and your cladding of choice. Otherwise as suggested some is better than none. 1" interior foam with some panelling or drywall over top. Ceiling should be insulated, vapour barrier, and drywalled regardless of your other choices for the walls.
billconner
Well-known member
or just eifs https://www.stocorp.com/eifs-stucco/
Another good choice. I saw a lot of this "acrylic stucco" installed in entire subdivisions in the 90's and early 2000's. For some reason up here it has fallen out of favor. My guess is that back then HRV and ERV's weren't really part of the house package so there would be moisture issues created in these houses as the interior walls also had a vapor barrier.
mike93lx
ALLIANCE MEMBER
Absolutely insulate the ceiling. You'll notice the difference immediately.
If you have any desire to reside the exterior, adding wall insulation out there would be a great option. Rockwool comfort board or a polyiso foam board would word well. Then add furring strips minutes through to the block and side on top of that
If you have any desire to reside the exterior, adding wall insulation out there would be a great option. Rockwool comfort board or a polyiso foam board would word well. Then add furring strips minutes through to the block and side on top of that
acer66
Well-known member
I am in a very similar situation like the op and am in climate zone 4.
22x22‘ cinderblock detached, was originally build to tend cows therefor was open at one end.
Previous owner turned into a work shop and closed that what with a garage door and a person door.
What I did was drylocked the walls, insulated the garage door which faces south with foam boards and most importantly put r38 insulation in the ceiling.
This setup without any insulation in the walls makes it okay for me to work throughout the year with the help of a single window ac during the summer and two radiant heaters during the colder month.
My plan down the road is to add insulation on the outside to get it even more comfy.
Outside because I am running out of space anyway and every inch counts and because I want heat/cool the garage 24/7 and as far as I understand means the insulation should be outside.
22x22‘ cinderblock detached, was originally build to tend cows therefor was open at one end.
Previous owner turned into a work shop and closed that what with a garage door and a person door.
What I did was drylocked the walls, insulated the garage door which faces south with foam boards and most importantly put r38 insulation in the ceiling.
This setup without any insulation in the walls makes it okay for me to work throughout the year with the help of a single window ac during the summer and two radiant heaters during the colder month.
My plan down the road is to add insulation on the outside to get it even more comfy.
Outside because I am running out of space anyway and every inch counts and because I want heat/cool the garage 24/7 and as far as I understand means the insulation should be outside.
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If anyone is interested, this guy
https://www.google.com/search?rlz=1...HXwPC5YQBSgBegQIBhAC&biw=1280&bih=601&dpr=1.5
is probably one of the most knowledgeable and respected experts in how to insulate, control moisture, ventilation etc. in the US and Canadian climate zones.
https://www.google.com/search?rlz=1...HXwPC5YQBSgBegQIBhAC&biw=1280&bih=601&dpr=1.5
is probably one of the most knowledgeable and respected experts in how to insulate, control moisture, ventilation etc. in the US and Canadian climate zones.
TomC750
Well-known member
This is good info, as we intend to reside the block house referenced earlier. The one thing we do not understand is what polyiso foam board is and adding furring strips "minutes through the boards" means. Thanks for the help.
Tom
mike93lx
ALLIANCE MEMBER
Lol. Auto correct screwed me. I meant mounted.
Polyiso is a form of ridgid insulation board. You can mount it to the block wall with a variety of fasteners, then you mount wood strips at 16inches on center on top of that. It provides a rain screen as well as mounting area for the siding
billconner
Well-known member
You can do cement based stucco over lath on foam for a more durable finish. The acrylic seems less durable near ground level, but in a slightly protected environment might be fine.
The exterior of my garage is brick. No intention to do stucco or any other exterior treatment that alters the current design/look.
mike93lx
ALLIANCE MEMBER
Located in Chicago. When doing the ceiling, what is the correct procedure? We had a new roof installed 2 years ago and have a roof vent. Rafters are 24" o.c.
Do I get baffles for each joist center, then paper faced fiberglass Batting, then a plastic vapors barrier? I don't intend to drywall or do any other finish treatment after installing.
D
Do you have soffit vents? If you do you need battles in each truss space. In your case I would suggest store bought versus home built. I also would suggest unfaced insulation if you are using a poly vapour barrier.
Cinder block garage with brick exterior, sounds pretty robust. I wouldn't change it either.
mike93lx
ALLIANCE MEMBER
Do not double up.on vapor barrier/retarder. Either paper face or poly. And that needs to go to the warm side. You want to stop warm, moist air from hitting cold air.
Not doing a covering makes it hard to support all the weight involved in insulating it really well.
billconner
Well-known member
Do you plan to heat it regularily?
Simplest is to install a ceiling - metal liner panel is good simple option - and lay insulation on that. Blowing cellulose on it would be my choice. Eave and ridge vents are the conventional choice but if not regularly heating, you can get by without.
Simplest is to install a ceiling - metal liner panel is good simple option - and lay insulation on that. Blowing cellulose on it would be my choice. Eave and ridge vents are the conventional choice but if not regularly heating, you can get by without.
Yes, I do have soffit vents. Here are some pictures to help visualize what I am dealing with.
Attachments
No plans for regular heat. Just a propane torpedo heater on occassion.
Yeah, you have a difficult scenario. 1 You can do a "hot roof" no venting. It's very detailed and can easily fail if not sealed correctly. Especially using moisture laden propane as a heat source. 2 You can add 2x2 furring on each truss, the added depth will allow you to have continuous 1.5 battles from soffit to ridge. Then add r12 insulation and vapour barrier. Vapour barrier and penetrations have to be meticulously detailed to prevent warm moist air from entering. You would also need a ridge vent to make it work. 3, my personal choice would be to add 2x6 rafters every 2 feet across the width of the garage. Tie them into the roof members and ridge beam with Simpson ties. Then install your 2 foot baffles between the roof members. Insulate the "ceiling* with fiberglass and install a vapour barrier. This will give you the most forgiving installation in case of any air leakage. I also wouldn't use propane for heating it, it produces too much moisture. A kerosene heater will serve intermittent duty quite well.
billconner
Well-known member
mzungu-
you say trusses but not trusses and the added 2x6 rafters - do you mean rafter ties to support a level ceiling?
Since it's a hip roof, need to think about ridge vent net free vent area.
you say trusses but not trusses and the added 2x6 rafters - do you mean rafter ties to support a level ceiling?
Since it's a hip roof, need to think about ridge vent net free vent area.
Truss - common rafter. 2x6 rafters - rather ties - ceiling rather - ceiling joist. Terminology differs from East to West and North to south. A hip roof probably has a dozen different terms for each piece of wood. Just trying to keep it simple.