Insulating a Building

Blown insulation blows. You will be cursing yourself for years if you go that route. Every time you have to go into a wall or the ceiling it will be a dusty, dirty nightmare, whether you use fiberglass or cellulose (DAMHIKT).

I would use batts for the ceiling and walls. You can go to a thicker batt if you want and compress it against the framing, the old phobia about reducing the R value by compressing fiberglass has been disproven.

Lowes has a relatively new insulation called "Miraflex" that I just tried in insulating my sunroom floor. It is about 9 inches thick, but comes on a roll compressed to about an inch. Unroll it, fluff it like a pillow, and install. Beautiful part is, NO ITCH. It's spun instead of chopped material. Best thing since women.

RJ Eastern NC

My garage addition is 2 x 6 stud contruction with R-19 batts in the walls. There is one shared (warm) wall and one open service door, but essentially no air circulation and no additional heat in the addition. No lights on or equipment running in the addition at the moment.

It's about -12F outside right now, windchill is -31F. The temp in the addition is within 2 degrees of the 68F in the main garage.

There's no problem (besides the additional cost) with using thicker batts.

Personally I'd go with R-25 unfaced batts in the walls.

If you use R-19 and leave an air space between the fiberglass and the steel, be sure it is fitted well with no gaps on the drywall side - it doesn't take much air flow (by convection) on the drywall side to negate the insulation.

The "miraflex" mentioned in another post sounds interesting and I agree with the comment about not using blown in the walls. But it's hard to beat the cost and performance of blown in a flat attic. So make sure you do whatever you need to in the attic up front...

Bob

IIRC (I opted not to go with Morton, eventually) they have large fibreglass batts sized for the 7'-6" or whatever it is that they space their framing on. Don't know how the price compares.

If you need to cut a hole in the ceiling with blown-in insulation, just find your location in the attic, cut the bottom out of a cardboard box or build a plywood one, rake insulation away from the area, then use the box as a dam to restrict the loose stuff from recollecting around the hole. When finished, remove box, rake insulation back into place.

RJ

insulation.

Thanks for the Miraflex suggestion; I'll check with Lowe's next week. As usual their WEB page is useless. Could it be that Lowes and Home Despot designed each other's WEB pages .

Here you go Keith

http://www.owenscorn>

Check out this site for foam info, interesting stuff.

Yeah, their claim to fame is that their product destroyed a space shuttle.

Gary

I'll second that one. HUGE improvement with spray foam - seals up water leaks from popped screws too!

On Thu, 29 Jan 2004 21:10:44 -0500, "Backlash" vaguely proposed a theory ......and in reply I say!:

Question. Is it glass or plastic? I have tried some poly insulation (hate the itch as well) and it burned like a beaut!

Yeah! And no itch!

Spike....Spike? Hello?

On Fri, 30 Jan 2004 02:10:10 GMT, "ATP" vaguely proposed a theory ......and in reply I say!:

Interesting. Not trying to start fight. OOI. Can you show refs to that?

Spike....Spike? Hello?

I'm sure you could find some stuff by googling it. R-13 for 2x4 walls is just more glass than R-11, and there are denser fiberglass products that have far greater R value per inch than standard wall batts. In terms of R value per gram of fiberglass, compression probably reduces it, but for any given space it appears that you can cram a good bit more glass in there than the old standard batt and gain some R-value, certainly not destroy it, as we were once led to believe.

If you go to a thicker batt and compress it, you will not get the advertised R, but you will get a higher R factor than using a batt that just fills the space. So using R-19 in a two by four wall will give you more insulation than the R-13 stuff. I don't know where I found this info. But will post here if I run across a ref.

Dan