Insulation... Last summer vs this summer

[Kevin C]

Last summer I had no insulation in the garage, on any 80+ degree day the sun on the roof and the sides got the place pretty hot. Even with window on the peak opened, there was not enough air moving to cool the place off.

This summer..... Fully vented roof with air vent channels from the eves to the peak. That and the rafters are stuffed with batt's of R30 fiberglass (the attic is part of the building envelope in case I ever want to use that space).

The walls have R13 in the 2x4's topped with 2" of R10 foam. It hit 85 today and the garage was about 73° inside. Last year is would have been 95°+ and 14,000 BTU AC just barely made a dent in the heat. Like I might get it down to 84°F. Today, it was cool enough to not have to turn it on.

I still have more work to do, but its really nice to see how well the insulation I have put in is working.

 

[Tweeker]

Great work. Reminds me of some things I need to get going on myself.

 

[benchracer]

Good info. I need to do this also. Hot as hell already.

 

[Kevin C]

I'm sure the cool floor is helping and that the place will warm up with consecutive hot days, but this is still a huge improvement. I knew it would be better, its just nice to see how much better.

 

[Gary S]

That tells the story. Insulation does more for you than a big heater or big A/C unit.

Always insulate first. Then heat or cool second.

My unheated garage stays 20 degrees below outside temperatures in summer and 40 degrees above outside temperatures in winter without paying for heat or cooling.

 

[NUTTSGT]

Kevin, I hope that put a smile on your face.


Winter/Summer, heat or cold this is the exact reason I always recommend insulating and tell people that "Insulation is an Investment."

 

[Kevin C]

Kevin, I hope that put a smile on your face.


Winter/Summer, heat or cold this is the exact reason I always recommend insulating and tell people that "Insulation is an Investment."

Big smile... and it makes finishing the interior a lot more tolerable.

The pace on finishing the interior is "as time and cash allows". Last summer I was still finishing the outside, as in siding, window trim and paint. Insulation was not yet on the list. Something about getting the outside done while the weather was dry.

Aiming a portable AC unit where I was working was the best I was going to do.

I like to think of the shop area as being in a giant foam cooler....

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The attic eventually gets the same treatment. What I did notice in the attic, was how well the R30 between the joists keeps the heat out, very effective. Right now it seems the heat that does get through is from thermal bridging across the joists.

A huge improvement and backs the theory that if you have enough insulation, a radiant barrier is not needed. From what I can tell, there is not a whole lot of radiant heat to block.

I'm hoping to be putting up sheet rock in two weeks or so.

EDIT: R23 wall (R10 foam, R13 batts) might be overkill for Portland Oregon, but I would rather go too far than have regrets later.

 

[BirdRacer]

I'm sure the cool floor is helping and that the place will warm up with consecutive hot days, but this is still a huge improvement. I knew it would be better, its just nice to see how much better.

I did the exact same thing, and got the exact same results. WOW I wish I had insulated mine from the beginning! The walls were done, but not the ceiling. I could feel the heat radiating down on my head more and more as the day wore on. I actually only got half of my ceiling done, and have it temporarily partitioned off. I can't wait to get the other half done. It's an amazing difference.

 

[Kels]

The insulation against the metal? Also any vapor barrier?

Can't wait to get my shop insulated, the place is a sauna right now and its not even summer yet!

 

[BirdRacer]

I have scissor trusses, and insulated at the bottom of the trusses. I have an air gap above that is vented from fascia to ridge vent. My 25k BTU A/C is loving me for it. It would run continuously and never cycle last year, and the temp would still gradually rise. It's only around 85-90 so far, but the A/C is cycling and keeping it 72 degrees with ease.

 

[Kevin C]

The insulation against the metal? Also any vapor barrier?

Can't wait to get my shop insulated, the place is a sauna right now and its not even summer yet!

The garage is old school wood framed. For this application, the foam is the vapor retarder.

I have been routing the back sides of the foam to clear the air lines and the conduit.

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Routed foam board.

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Conduit and air lines. AN no, I did not include any drip legs on the final loop. There is a large one at the start of the run, I use filter separators when needed. So far, not an issue, that and I have a 25 SCFM dryer.

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Static cling....

 

[Kevin C]

I have scissor trusses, and insulated at the bottom of the trusses. I have an air gap above that is vented from fascia to ridge vent. My 25k BTU A/C is loving me for it. It would run continuously and never cycle last year, and the temp would still gradually rise. It's only around 85-90 so far, but the A/C is cycling and keeping it 72 degrees with ease.

We all know its supposed to work... But still, its nice to see that it actually does and you get something back for the effort and cash you put in.

 

[BirdRacer]

We all know its supposed to work... But still, its nice to see that it actually does and you get something back for the effort and cash you put in.

Amen! It's an amazing difference. Hell, I love it just for the sound difference in the shop. I can't wait to get the other half done and take down my temporary tarp divider.

 

[ddawg16]

You would be surprised at what just drywall does....toss in insulation and life gets much nicer....

Side benefit.....noise....the drywall and insulation knocks down the noise quite a bit. I can now run my table say late at night with the door closed and no one knows it.

 

[Air_Cooled_Nut]

In a couple weeks we'll upgrade our original 1970 rock wool, currently about 5" average depth, with blow-in to bring us up to code of R-38. Can't wait! I knew we needed it but when the thermostat reads "Recovery mode" then it's going too long. Darn cheap previous owners...

I insulated my previous garage with just R-13 and it made a noticeable difference (Beaverton area). I think going a little more certainly won't hurt, we get our moments of heat/cold

 

[norsea]

You can give your money to the insulation manufacturer once, or you can give it to the gas/electric company forever. The choice is yours.

We live in the desert; 110F+ temps in the summer are common. While the winters tend to be mild we do have occasional bouts of freezing days which will cause all the plumbing lines that people ran over their flat roofs rather than pay to have the job done right to freeze.

Radiant barrier OSB is also a good investment for your exterior walls/roof. When we were redoing our roof I used a thermal heat gun to measure the difference in temperature between 7/16" OSB with/without the radiant barrier; the difference between the various sheets I tested was 11F to 15F cooler on the radiant barrier sheets.

This is a significant difference as far as I am concerned.

Another thing that is quite common in this here part of the world (Palm Springs, CA) is to install closed cell foam as the roofing material with an elastomeric coating. Each inch of foam offers approximately a 7.5 R factor. While that is good the real benefit is it also provides an excelent thermal break.

Combine the radiant barrier OSB, the foam roof and R30 insulation in the 2"X10" rafters (flat roof) and you have a very formidable barrier to heat/cold.

I also put a one inch butter coat of closed cell spray foam on the inside of all of my exterior walls. This provides an excellent seal for keeping cool air in and hot air out. It does take more work to get the insulation installed properly in the walls but it has been well worth it. SWMBO has done all the insulation and the excellent job she has done shows.

Add 5/8" sheetrock to all this and we have a well sealed building that requires minimum expense to heat/cool.

There is one thing I would add to this if I were to have a do over. I would add 2" sheets of styrofoam to the exterior walls prior to stucco being applied. This would provide an excellent thermal break as well as additional insulation. I don't know why I did not do it.

Jim

 

[38Chevy454]

Shows that insulation is good for both hot and cold. It moderates the temps inside the building. I always recommend to spend the money on insulation, it will pay back in comfort and utility costs.

 

[Dustball]

I bought my house last fall and this is the first house I've lived in that was a raised ranch with a 3 car garage on the main floor. I have a thermometer in the garage and no heater or air conditioner in the garage. The garage is fully insulated (walls and ceiling) and here's what I've observed so far.

Winter- temps hold around 40 degrees in the garage even when it got down to -10F. Summer- temps hold around 64 degrees even when it was 90 degrees outside.

The slab and earth is doing the heating/cooling for me.