Thread: Insulation (of a Garage Nature)

Originally Posted by SHOTIME

You didnt have to do the sides at all?

haven't gotten that ambitious to check all the walls, but the ones I did check had insulation in them.

If you mean the sides/end of the attic - no, the goal is insulate the box of living space (only) and leave the roof/attic to do it's own thing thermal-wise.
You may notice if you look hard, those pink channel looking things stapled above the insulation? Those run down to the eaves of the house and between the eave vents and the ridge vents, let the nice nice air flow without trapping heat in the attic.

With the insulation, the goal is to not let any heat get into the attic from the house. BTW, the federal recommendation is 19" of insulation . I've now got the 9.5" in my garage, but if I was going to live out there (like sleep too) I would toss another thing of R30 atop the current ones.

As for the walls - are the finished walls insulated or just mudded/painted?

As for the ceiling...few different ways, the good news is you don't need to finish it to insulate it.

I'm a bad admin, but I'm at my real job and busy, but promising to split out an insulation thread off of this later

Originally Posted by SHOTIME

Thanks, I'll wait for that :-)

dishes are done!

Originally Posted by SHOTIME

I was hoping I could relate your findings in my own situation.
Half of my garage is finished where it becomes an exposed portion of the house, the other half is bare. So I have to insulate and drywall the bare sections.

I dont know what type or value insulation to use, nor do I know how.. generally.

(See where the drywall ends on the far left. everything behind me is finished.)

Attachment 18441

I also need to know how to handle the ceiling. I love the fact that it is high and the storage that is available up there, but it would be a huge heat suck.
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Half is finished to meet code. The part of the garage that touches the house has to be a firewall. If you don't finish off the attic you'll never be able to heat that.

SSG why on earth didn't you blow the insulation? That must have sucked.. not that blowing it doesn't too, but dang...

Originally Posted by 08silvercbr

Half is finished to meet code. The part of the garage that touches the house has to be a firewall. If you don't finish off the attic you'll never be able to heat that.

SSG why on earth didn't you blow the insulation? That must have sucked.. not that blowing it doesn't too, but dang...

Yeah the opposite of blowing is sucking, correct- it was no fun at all.
Blown-in stuff collapses over time, we had blown-in in the other half of the house and it's gotta be about R-3 equivalent by now, I actually rolled encapsulated R-30 over it earlier this year and noticed a big difference in heating this year.

Originally Posted by SomeStrangeGuy

Yeah the opposite of blowing is sucking, correct- it was no fun at all.
Blown-in stuff collapses over time, we had blown-in in the other half of the house and it's gotta be about R-3 equivalent by now, I actually rolled encapsulated R-30 over it earlier this year and noticed a big difference in heating this year.

Huh.. That stuff in our attic must be up to my knees and its 7 years old.

I determined years ago that sucking was a good thing. So from now on whenever something is cool you say it sucks.

Blowing it in is far worse than the sheet stuff, plus it takes two people.

Originally Posted by ND4SPD

Blowing it in is far worse than the sheet stuff, plus it takes two people.

Really? Even when you have to make all those cuts and squeeze under the trusses? Other than the mess I didn't think it was bad. 2 people.. SSG, and MrsSG ?

What cuts? The stuff SSG has is pre-cut, you just lay it in. Even if you get the rolls you can pre-cut them. Take a broomstick up with you to push it out to the edge where you can't reach. I've blown insulation in twice at the same time - the first and last time I'll ever do it.

Originally Posted by 08silvercbr

Huh.. That stuff in our attic must be up to my knees and its 7 years old.

I determined years ago that sucking was a good thing. So from now on whenever something is cool you say it sucks.

Yeah if left undisturbed it's fine, maybe...but replacing some exhaust fans, and dealing with mice when we first moved in meant lots of trips through that winter wonderland.

Leaving the second part alone, cause it sucks.

Originally Posted by ND4SPD

Blowing it in is far worse than the sheet stuff, plus it takes two people.

For a garage I don't think it would be too bad actually, but there would be a hellacious mess all over the place. Yeah the whole feeding and running up and down ladders would be annoying for a solo gig.

Originally Posted by SHOTIME

So my garage is 2x4 construction, whats the biggest R value I can fit in the with drywall over it?

what kind should I buy?

Do I just roll it in, and staple it to the plywood? Paper side out?

R-13 is for 2x4 construction. Make sure it's 'faced'. Brand.. Home Depot carries Owens Corning. (not sure the brand matters) Buy an electric stapler for 20 bucks. (it's worth it) Open up the lip of the paper and tuck it in on the inside of the 2x4. You want to staple it back far enough that it won't be pushing on the drywall when it goes over it.

Originally Posted by SHOTIME

So my garage is 2x4 construction, whats the biggest R value I can fit in the with drywall over it?

what kind should I buy?

Do I just roll it in, and staple it to the plywood? Paper side out?

Just to be clear, the vapor barrier/facing is to face the inside of the treated space, so in this case you should see brown paper when you look at your walls. I stapled mine to the face of the studs so I have a uniform level of vapor barrier there, it touches the finished surface, life is good. I could be wrong - just telling you what I did

The whole vapor thing may get a bit confusing when you first get into this. Think of it this way...anytime you heat/cool it causes humidity to raise or drop. Humidity is the presence of water (vapor) in the air. The vapor barrier prevents the latent water vapor from getting into that expensive insulation and turning it into a giant sponge and rotting your framing. There are other reasons that may or may not be larger, but in new england and a propane heater in the garage - thats what it's doing for ya.

When I did my shed where I used to live (only 10x10) I actually plastic sheeted the walls and floor once I was done with all the insulation, and cut snugholes for all the outlets and fixtures. That thing is tightly sealed...wish my house was just as easy to seal . Whatever you do, it doesen't have to be exact everywhere, but make sure you fill in any areas around outlets or fixtures with the fuzz or some kind of barrier if possible. It's not imperative since this isn't a living space and you will be leaving it untreated more often than treated (temp wise).

Also, check out Lowes...I am not sure how much the stuff was, but they had R-13 and R-19 insulation there (by Dow) that is blue...and itchless. You could seriously build a sweater out of it. I would almost think they found blue sheep and shaved them, but this is even softer than wool (now we'll see of SOB is reading this thread too).


hope this helps...

Originally Posted by SomeStrangeGuy

Just to be clear, the vapor barrier/facing is to face the inside of the treated space, so in this case you should see brown paper when you look at your walls. I stapled mine to the face of the studs so I have a uniform level of vapor barrier there, it touches the finished surface, life is good. I could be wrong - just telling you what I did
...

If you do it this way it will put pressure on the drywall. You'll have bad screw/nail pops. On that note I hear now people are using liquid nails on the outside face of the studs, screwing the drywall down for a week, then removing the screws.

eh? if you face the vapor barrier in?

nail pop occurs from moisture expansion amongst other things, so i would assume keeping moisture from the studs would be a good thing?

not to mention i bet a dollar he wont drywall the whole garage: )

Originally Posted by SHOTIME

First of all thank you all very much for your time. and thanks SSG for splitting out the thread.

the air between the fibers is what helps the insulation correct? so its a mistake to staple directly to the back wall?

When the garage was built there are spaces between the plywood, I can actually see the bright sun through the siding. Should I use some type of expanding foam on that joint?

What is the best kind of drywall to be using in a garage?

The air is key - don't mash the insulation, you want trapped static air and compressing insulation greatly reduces R values.

Sun through the siding?? gaps in plywood? does this occur in winter or summer or both? that sounds weird...unless I am missing something. Sure it's not reflective tape or is there actually light shining in?

If it were me, I would use furring strips and pegboard, or some of that plastic board stuff, screw drywall

Originally Posted by SHOTIME

Whats the best way to insulate the top and keep the heat in?

I can buy the metal faced foam board and mount it on the rafters. Should point the heat back down right? Or just insulate on the roof?

All depends what you want to do in there...I would either close the ceiling off with panelling/drywall, make an access hatch as large as you might need for storage, and then insulate it with R-19, OR just insulate the roof the same way you did the walls.

Depends what the heat source in there is going to be and how it's attached to the house...

I'd put up drywall - adds an extra layer that insulates, plus you can paint it white to brighten up the garage for those tedious projects.

After thinking about this some more, and looking at your garage pics...I guess I would have to agree with Z. I never realized how dark my garage would be without the white walls (now covered up by crap anyways).

Interesting, guessing it was done like that for expansion purposes or something since it seems pretty straight and I presume that wasn't intended on being a treated space. Can you tell if on the outside there is tyvek or something under the vinyl siding or is it just siding on there?

If it were me, because I am not sure exactly why that's there...I would say put some silicone caulking on it and let it cure before you put insulation in. I don't think the gap is anything to be worried about, but you just don't want stray moisture using that as an entry/condensation point.


Speaking of insulation, on the plus side...my garage seems to sustain temperatures a bit better with it in there

Wow.. Bwhip might better explain this, but don't they usually put tyvec (or something) on the outside of the plywood?