Let's talk insullation...

[bluesman2a]

OK here's my situation:
2X6 framing on a 18X25 with 14' sidewalls.
Already have an insulated garage door.
Have no other insullation or wall covering at the moment, finishing up electrical for rough inspection.
I plan on going with OSB screwed to the walls with possibly sheet metal on the lower 4' for water-resistance/looks.

My original thought was to go with R-19 in the walls and R-30 in the ceiling. In older part of the shop (2X4 framing), will do R-19. Looking at doing faced batts.

So my first question is: with my situation can anybody see anything wrong with this approach? Suggestions/tips to make it better/easier/cheaper?

I've decided against foam because of the cost and adding wiring later, but are there other alternatives I should consider? I've been hearing a lot about, bubble, cellulose and recycled denim insulation, anybody have input here? Cost for R-value is there anything that I can do better on the DIY track?

 

[hewl35]

Here's what I'm doing .My garage is built into the side of a hill so I have poured concrete on three walls plus one wood framed for the entry. I'm planning on furring the concrete with 2*4's but backing them away from the wall to allow for kraft faced R-30 with 8 mil vapor barrier. I'm planning on using the same r-factor for the roof. I also plan on using plywood for a wall covering. I've thought of using steel or galvenized sheets over the bottom half but have heard that it bounces noise extermely well. I would like to be able to wash out the garage and not worry about mold problems. I have gone over the framing and sealed every small hole with foam or insulation.

 

[mhoffm911]

Looks fine to me. I did blown-in for my ceilings instead of batting.

Only question I would have is related to the 2nd post. If you are using faced batts, it is my understanding that you don't need the additional vapor barrier as the facing on the batts acts as one. If you have 2 vapor barriers, you are possibly creating a moisture barrier, thus leading to possible future problems such as mold.

 

[boiler7904]

Kraft-faced batts will be fine. It isn't the latest and greatest form of insulation but it works. I'd probably blow cellulose into the attic. Mhoffm911 is right. You want 1 vapor barrier - kraft facing counts as a vapor barrier. The second vapor barrier will trap water vapor in the wall which leads to mold, rot, and other fun stuff.

To make it cheaper, buy the insulation before January 1 and keep the receipts. You'll qualify for a tax credit on your federal tax return. You get back 10% of the purchase price up to $500.

Energy Star Federal Tax Credits

 

[PanelDeland]

I did insulation for a living for about 6 months.It ain't rocket science and I am by no means an expert.Here's what I know.Kraft faced batts have the insulation glued to them then they are stapled to the studs.This helps prevent settling of the fibreglass.Non faced batts will eventually settle(at least some from vibration and such.)Once you have covered the entire frame with batts you will want to go back and fill in any small gaps anywhere.Even if you have "sistered" stud with a small gap between them you need to fill that space.I know it may sound overkill but the gaps around window framing need it too.I have been in places where these areas were not adressed and you can feel the difference.The blown in is the way to go in the attic since it leaves no small gaps.If you want to use batts in the attic space it will be better than not insulating it and you can go back and blow in over it when you can.
I also suggest you use the fibre style (LIke pink panther) over the rockwool batts.The rockwool just seems to settle more.Flammability is an issue in a garage so I would check and be sure you get an idea of fire rating also.
Like I say I'm no expert but these are some things I learned.It's been quite a few years since I did any but these things probably haven't changed.

 

[Kevin54]

I put R30 batts in my attic. For one the ease of installation. My wife and I did my 28x36 garage with batts in about 2 hours. My 30x 50 area in my house with blown in, took the whole complete evening and I was cleaning up dust for months. If I had to do it over again, either I would hire someone to blow the insulation in, or i would have put the batts in the house. And blow in will settle considerably either in the wall or ceiling. When our house was built in '88 they blew in insulation in the attic. We bought the house in '93. By '98 the insulation had settled to almost the top of the trusses. So in 10 years time it has settled almost 8". I blew in 12" on top of that in '98 and you can see where it has settled yet again, although not to that extent. And for a pole barn or garage, after insulating, I would go over the entire perimeter with a vapor barrier. Doors get open and closed enought that it will not create a moisture problem like a greenhouse. That is unless you have floors that sweat alll of the time. A good vapor barrier will keep any air infiltration out if done correctly. But the key is good insulation techniques. Fill all voids. Almost any house that you go around, if the wind is blowing, feel around the window trim, outlets, baseboards. somewhere you will feel air. Put a vapor barrier inside, cover the outlet, switch boxes, "X" it with a blade, tuck it back and wrap it with a small piece of duct tape. Caulk at the sill plate and floor, foam around doors and / or windows. Use care with foam though as it will greatly expand and can bind.