Attic Insulation

[Jeff]

I need to insulate the area above the shop. I've looked at batting, spray foam, and blown-in. This will be a DIY project. I'm looking at an area approximately 20'x20' with no existing insulation.

After much research and trips to HD and Lowe's I'm more confused than ever. Since I'm in Florida I know it should be at least R45 or better.

But which product, for the money, is the best deal?

Input is appreciated before I gouge my eyes out with a scratch awl!

 

[Rosco]

what are the dimensions and layout of the area? Never heard of R-45 being required in Fl. I am in south Ga. and R-30 or above is called for here.

 

[Jeff]

what are the dimensions and layout of the area? Never heard of R-45 being required in Fl. I am in south Ga. and R-30 or above is called for here.

Code is R30, but the previous owner had R45 installed during construction. Why they never insulate above the garage/shop is beyond me.

The basic dimension is 20x20 with a standard pitched roof above.

 

[Rosco]

If there is easy attic access I would go with blown in cellulose. Lowes will let you use the machine (I think) if you buy so many bundles. Either that or unfaced fiberglass is the best on the budget. The best approach to fiberglass is two layers installed perpendicular to each other, and the first layer should just fill the cavity. Spray foam requires a contractor to install (they sell kits, but very very expensive)

 

[54FordPanel]

HD also rents you the machine for free with a purchase of 20 bags at $10.79/bag. That's the recycled stuff, which I think works just fine. I've done it 3 times in houses.
For me, blowing it in is way, way easier than rolling out batts.
They also rent the machine for blowing in fiberglass insulation.

 

[sheslostcontrol]

Before installing blown-in insulation, do we need to install any vents or passages along the corner of the roof/ceiling (where it meets by the gutter, inside the house)?

Do you just cover up existing electrical?

 

[54FordPanel]

In Colorado, the more roof vents the better. Lots of soffit vents, and then lots of vents up high along the ridge. And then when you blow in the insulation, you don't want it so high down on the ends that you cover up the air flow to the soffit vents. You want some air flow from the soffits to the peak.

I would do all the electrical work you want to do in the attic before you insulate. You can do more later if you need to, but it's easier (obviously) to do it before.
And yes, you just cover everything up. Some flush mounted pot lights are not IC (insulation covered) rated, but that's the only thing I can think of.

 

[tdkkart]

Before doing the blown-in yourself check with some of the insulation contractors. When I did my shop I found that I could have the blown-in done professionally for less than it would have cost me to buy just the insulation. For the money I wouldn't even crawl up in the attic.

 

[Kevin54]

I'll take rolling out batts anyday over blowing in. We blowed in more insulation in our house a few years back from Lowes and it was the dirtiest nastiest job I think I have ever done. That **** goes everywhere. My wife and a buddy was loading the hopper and I was doing the attic work. The dust was terrible down below and the garage door was open because that was the only attic access. I think I cleaned dust out of the garage for a year. When my wife and I did my garage with R32 Batts (28x36 area) we started in and was done 2 1/2 hours later and that included taking a beer break. Way cleaner than blow in. She handed me the batts as they were in 8' lengths and I layed them out.

 

[Jeff]

Thanks for the replies.

I called a couple of insulation companies yesterday and found its almost the same cost to have them do it.

$210 for blown-in R30 insulation with soffit baffles. They'll be here in the morning.

Thanks!