Garage insulation?

[scoly]

With the help from many people here have decided to insulate my garage but am at a loss on where to start. I have one outside wall and the ceiling to do. Do not want to tear out sheetrock but have heard about a foam that can be blown in thru holes at the top of the wall between the studs. Can this be diy? Also the attic is floored and heavily loaded. Can I use the same foam for this or should I blow in the normal insulation?
Thanks
Steve

[SteveR]

quote:Originally posted by scoly

With the help from many people here have decided to insulate my garage but am at a loss on where to start. I have one outside wall and the ceiling to do. Do not want to tear out sheetrock but have heard about a foam that can be blown in thru holes at the top of the wall between the studs. Can this be diy? Also the attic is floored and heavily loaded. Can I use the same foam for this or should I blow in the normal insulation?

Hi Steve,
I am not sure what you are referring to as far as "foam", but some I have seen are an expandable type and may cause havoc on the gypsum board. For sure, with the vertical wall, you can use blown-in cellulose insulation. This gentleman's webpage shows the methods very well, as it is a DIY project with a blower from lowes or HD.
http://www.just4fun.org/woodworking/.../shop_heat.htm
As far as the attic with a floor, and I am only guessing here, maybe a series of holes at each joist space...one each at the ends and some in between the spans. Maybe even large enough to be able to angle the hose in so it can push the insulation in horizontally. Otherwise the area/hole may fill up to quickly and you will have alot of gaps of no insulation.
You will be very happy with insulating your space..makes a night and day diffence. Then your 10k AC unit may be all you need. I have a 7k? one for a two car space and only the walls are insulated so far...I suspect after I get the ceiling done it will be even better.
HTH
Steve

[onedash]

I was just wondering if you have A/C in your Garage do you keep it on 24/7 ? If not don't you get condensation on your tools?
Im renting and have a two car garage so I just use a fan to make me think im not as hot as I am.

[LarryG]

Retrofit foamed-in-place insulation is often installed by cutting a slot about midway up the wall, so that the installer can insert his spray nozzle and shoot both up and down. This also provides a means of dealing with any solid blocking that may exist at the midpoint of the studs.

I've never heard of the foam being a problem for gypsum board. It expands to fill the space available, but nowhere near forcefully enough to pop the nails; and it dries within seconds. This stuff is pretty spendy, though, and AFAIK the equipment needed to do it cannot be rented for a DIY install.

Broadly speaking insulation does not weigh enough to make much of a difference in the loading ... probably just a matter of ounces per square foot. Of course it all adds up so if your existing joists are overstressed already, technically speaking adding the weight, however neglible, of insulation will only make matters worse.

[SteveR]

quote:Originally posted by LarryG

I've never heard of the foam being a problem for gypsum board. It expands to fill the space available, but nowhere near forcefully enough to pop the nails; and it dries within seconds. This stuff is pretty spendy, though, and AFAIK the equipment needed to do it cannot be rented for a DIY install.

Larry,
I may have spoken out of turn here..just the stuff I have seen on the home improvement shows (new const.) seems to expand like mad...then they come in after and shave it flush with the studs. So take my statement with a small grain of salt!! LOL
I agree.....the added weight should not be a deal breaker.
Steve

[SteveR]

quote:Originally posted by onedash

I was just wondering if you have A/C in your Garage do you keep it on 24/7 ? If not don't you get condensation on your tools?
Im renting and have a two car garage so I just use a fan to make me think im not as hot as I am.

Only when I know I will be in there. Could be an issue in moist climates?....I live in a low humidity area.
Steve

[scoly]

Thanks for the info. Didn't realize the sprayed foam was an installer only product. Guess the technique and equiptment require a level of expertise. May get a quote but after searching the net cost seems to be a bit of a hurdle. Did find a kit product that the company claims diy status but at over $600 to do one wall think I will go cellulose. May not be as high an r rating but should take care of my needs and can be had local. Steve
The link was a great primer. Don't see any problems with doing it this way. Have a project to finish and next will be insulating.
LarryG
Your right about the spendy part for sure. Didn't really intend to imply weight as a problem. More of an access problem. From reading I've done since the post you are correct about the expansion not being a problem though they do recommend a slow expansion product that I assume is to lower the possibility of to rapid expansion which could cause the sheet rock to be forced away from the studs.
Onedash
I only run the ac when I'm working and have no problems with condensation. Always heard that refrigerated ac takes moisture out of the air but what do I know.
Once again thanks for the help.
Steve

[LarryG]

There may well be foam formulations that expand forcefully enough to blow a wall apart; I don't know. I do know that there is a kind of sprayed foam that can be used in existing walls because I've seen it done. But it may be a slightly different product than is used in new construction.

Although it'd be more money, you might consider taking off the gypsum board, insulating with batts, and then recovering the walls with OSB or plywood, so you can hang stuff on the walls anywhere. Blown-in insulations work pretty well in attics but putting the stuff in walls is a crapshoot because it can get hung up on the way down, or stopped completely if there's any wiring or piping or blocking in the way; and it's prone to settling over time. When you consider that batts plus the new wall material would be totally DIY, and could have some added benefits ... might be worth running the numbers to see if it's at all viable.

A variation would be to cut enough holes in the gyp to ensure you're getting a good fill, then cover everything up with OSB or plywood (without patching the access holes).

There are, however, some possible code issues with either of these ideas. If the garage is attached to the house, at minimum the common wall(s), possibly the ceiling, and possibly even all walls will have to be fire-rated gypsum board. Any holes cut in this would have to be repaired, even if you did cover it with another material.

[scoly]

Wow! Larry, that's a great idea to cut more than one hole to be sure of a complete fill. If I am going to do it may as well do it right. Really don't have the energy to remove the old sheetrock and redo the wall. Feel sure this would be the best but I'm not really up to it.
Thanks
Steve

[Tom Miller]

Is there any chance you need a vapor barrier if you're going to insulate? I know in Minnesota you'd be asking for trouble. [B)]

Re: the foam. I think there may be a few versions of this out there. One is relatively new, and is some pretty heavy-duty stuff. It's sprayed on the underside of floor boards in between floor joists from below, and dries pretty rock solid. IIRC, it is it's own vapor barrier, too. This might be the stuff that could stress your gypsum.

Then there is the spray foam like you can get in the little cans. I don't know how big a scale you can do this stuff, but it might be an option.

Re: cutting a big hole and blowing in insulation -- You could cut the top (and bottom) foot of drywall out all around the perimeter. A single 8' sheet would patch 32 linear feet of wall perimeter.

If you cut at the bottom, staple up some plastic to hold in the insulation.

Regards,
Tom