garage insulation help(updated pics1/27)?

[bigred1]

i have a new garage 22x26 2x4 walls from what i gather the recomendation for walls (in my area of Nebraska) is r18 i read the way to achieve this is r15 fiberglass and 1/2 to3/4 inch foam board. others say to just use the r15 with kraft for vapor barrier, still others say i should use plastic sheathing over the insulation for vapor barrier. can anyone shed some knowledge about insulating a garage? i have to get this done before they will finish installing electricity. PLEASE the imediate future of my trikes depends on your help! sorry a little dramatization there lol. thanks for the input.

[nate b]

I would just use R-13 unfaced fiberglass and then install a 4 mil plastic vapor barrier over and sheet rock or plywood over that. Most of your heat loss is going to go through the ceiling. I usually run a R-38 in attics if possible, here in wisconsin.

[YTM 225dx]

I agree with nate out here in Illinois we run kraft faced r13 on the wall and on the ceilings i would put a kraft faced r19 should be plenty insulated with that kind of insulation. Good luck

[atctim]

I find in very odd that you have a new garage with 2X4 walls - i would think in Nebraska a 2X6 wall would be code to accommodate for more insulation. But then again - code for garages may be much different than that of a dwelling.

Did you build it yourself - or have it contracted out? Also - How high are your ceilings?

[Dirtcrasher]

The problem with 2x4 framing is that you need to keep the insulation fluffy. It has a better R value when fluffy versus stuffed in place. That only leaves you just under 4"s for insulation thickness. The insulation board they sell is very expensive, all insulation is very expensive. It would have been better if it were 2x6 walls. Trust me, I know how expensive this stuff gets.... To reach that R value you'd probably need insulation board on both sides of that wall, one under the interior finish (sheetrock?) and one over the plywood exterior before vinyl siding. IDK what type of finish your building.....

I hooked up with a guy that builds metal buildings and he gets me the 3 foot wide x 20' or more ends of the rolls. Be good to try and find a space metal building guy and see if they have leftovers. I was paying 25$ for a truckload!! For our area in the N East, I have plenty of insulation in my walls.

[ATC185R]

Finish the wiring and then go ahead and put your inside sheeting up (plywood, chipboard, etc.) Then buy some styrofoam blow in insulation. It is simply loose styrofoam BBs. Put it in trash bags and dump it in between the studs from the top. We did this to our large farm shop and it is pretty comfy. No idea on the R value but I think it's pretty good. No idea how much this stuff costs- we had 4 stocktrailer loads given to us. One drawback is that it is very messy- it will look like it snowed when you are done. Don't know if this will fit your application but we sure like it. Some say there is a machine that will blow it in, others say it won't work. We just used trash bags and cardboard boxes. Anyway, something to think about. Another option would be the spray on expanding foam. (industrial "Great Stuff") This would depend on if you wanted to use inside sheathing. Hope this helps--AJ

[Yamahauler]

pink fibreglass is aprox R-3.4 per inch
extruded polystyrene (Blue or Pink styrofoam) is R-5 per inch
expanded polystyrene (Beadboard) is R-3.7 to 4 per inch

if you want R-18. you would need to fill the cavitys with polystyrene which would cost the most and would only be r-17.5.

You should figure out how much it will cost to buy 2x4's and rip them in half, nail them to the edges of the existing 2x4 studs then you can put R-20 pink fibreglass in the cavitys.

Use 6mil poly as a vapour barrier and tape all the joins with tuck tape

[bigred1]

I find in very odd that you have a new garage with 2X4 walls - i would think in Nebraska a 2X6 wall would be code to accommodate for more insulation. But then again - code for garages may be much different than that of a dwelling.

Did you build it yourself - or have it contracted out? Also - How high are your ceilings?

i'm not familiar with all the codes but it was built by a garage company and i have permits.

[bigred1]

thanks for all the feed back guys. after talking to more people around the area i think i'm going with the r15 insul. and 1/4 or 3/8 OSB for the walls and for the ceiling OSB and maybe a double layer of r19. we've had weather now at -15 and no insul. I can manage with overalls a hat and gloves not ideal (but not the worst i've delt with cosidering the last 4 winters at this house i didn't even have a garage lol) so i think with this application and a portable 35,000 to 150,000BTU it will be enough to get me through the realy cold days. let me know if you think i'm missing anything and thanks again for all the feed back.

[400exguy]

Another option would be the spray on expanding foam. (industrial "Great Stuff") This would depend on if you wanted to use inside sheathing. Hope this helps--AJ

If your talking about the actual stuff they came out with for insulating, that stuff is SUPER expensive from the little I looked into. I hear it is the best though.

As for all the other blow in types, I also hear they can be really messy especially when you "over fill" and it comes out the hole of application.

Once again im just going from the little I have seen/heard while my brother was looking into all the alternatives.

[Yamahauler]

stay away from blow-in in the walls. After you fill, it settles, and you have a void at the top of each stud cavity. which will be a cold spot.

whta is a double layer of r19?

[nate b]

I would recomend not using 1/4" osb on the walls.

[bigred1]

whta is a double layer of r19?[/QUOTE]


just two layers of r19. r19 is what isaw at the hardware store for attics, there might be something better for the attic i'm still looking on that part.

[bigred1]

I would recomend not using 1/4" osb on the walls.

i was wondering if it would be to thin, is this why?
would 3/8 be sufficient then?

[Yamahauler]

I would put nothing less than 3/8" on the walls.

By this R19 stuff..this doesnt happen to be p2000, does it? if so. dont do it, its a total scam. you may get R4/inch at the most. Plus you will be paying over twice the price of beadboard