blown in versus roll in insolation

[Cyrille de Brebisson]

hello,

I am building a garage (workshop at the bottom and office at the top)... and I am getting to the insolation part.

the structure looks like this:

/\ / \ / \ |----| | | | |

with 10" beams on the roof part and 8" beams under the floor. all 24" of center...

the under roof area is an office and need insolation. I am wondering what you thought about the advantages and disadvantages of blown in versus roll in insolation, cost issues and choices (recycled paper vs non paper blown in)?

regards, cyrille

[-MIKE-]

Some thing *I* would consider are... Blown in-- PROS: when done properly is better because it has no seams, it gets into the nooks and crannies, it's certainly easier to install, and is cheaper (at least last time I looked into it). CONS: pain is the a$$ to deal with if you need to get up in the attic and install anything in the ceiling. If NOT properly installed, it can get into the eaves and block air convection that flows from the eaves/soffit vents up the roof and out the ridge vents, to cool the roof and prevent condensation. Installation can be daunting for the first time DIY-er, working alone.

Rolled fiberglass-- PROS: is much easier to move around and out of the way when having to work in the attic/ceiling. Can be installed by one guy without any special equipment. CONS: doesn't seal as well, because it can't get into tiny little spaces, and the seems don't always line up or take up the necessary space. This is assuming that you, like 99 percent of homeowners, are

*not* putting enough insulation in your attic, which would often involve 2 layers, crosshatched, which would cover the seems. :-)

Nice compromise: lay down one layer of rolled, between the roof joists, then blown on top of that. That way, if you need to work in the attic, you can peel back the rolled, with the blown-in sort of rolling back with it. And if you have to cut holes in the ceiling, you don't get rained on by loose insulation.

my 2 cents

[PDQ]

Given the steep pitch (?) of the roof, consider a foam sprayed on = insulation. It would go between the rafters forming a solid draft = shield and, given the latest upgrades to this urea foam, would probably = result in an R-30 or better value.

A fringe benefit would be plenty of space on the joists to store = supplies off the floor.

P D Q

[Morris Dovey]

I /don't/ want to be a spelling nazi - but I think you mean "insulation" rather than "insolation". Both are Good Things, but "insolation" refers to the amount of sunlight that falls on an area, while "insulation" refers to a heat barrier.

But you did really have me going for a moment. :-)

[clare]

The only blown I'd go for is Urethane foam. Put plastic pipe in to pull wires through in case you need to add circuits or change wires. Tight, clean, varmint-proof and permanent.