On Thu, 30 Jun 2011 09:56:36 -0500, "HeyBub"
wrote:

ls02 wrote:
I am thinking about using blown in cellulose insulation for new
construction: walls, attic as well in floors between first and second
floor and between first floor and basement. I have a lot of pipes and
wires so I suspect blown in cellulose will provide better value then
fiberglass batts which hard to put around so many obstacles.

Has anyone done this?

What's the cost of blown in cellulose vs fiber glass batts?

What's the best way to apply it to walls and floors? I saw video when
they blow it to wall open cavity then use some sort of screed to
screed excess flush with walls. What about floors? If I blow it to
ceiling will it stick and not fall down?


Not cellulose. The stuff you see squirted into an open wall is polystyrene
foam (think Great Stuff).


No, he is right - spray cellulose IS used - a LOT in some areas.
Polystyrene foam is NOT sprayed in place. Urethane foam is.
Personally I don't like the cellulose, and prefer the urethane foam.

There is standard wet applied cellulose, and stabilized cellulose -
both of which seal quite well and do not suffer from settling - as
long as they stay dry after application. Both require a minimum of 24
- preferably 48 hours drying time before covering with wallboard.

Stabilized cellulose is generally used in ceilings and on the bottom
of roofs.
Sprayed foam has superb insulating qualities (R=6+/inch) and not cheap.
Fiberglass is about 2/3rds (R=4/inch) the insulating qualities of foam.
Cellulose has about the same R-value as fiberglass, but is typically applied
in a thinner layer resulting in an overall lesser R-value than fiberglass.

You can't easily use blown-in cellulose on a wall.

He is NOT talking old school blown in, or "loose fill" cellulose.
This stuff goes in wet and sets up like a combination of felt and
papier mache.

To do so, you have to
finish the wall, open a hole, fill the cavity, then patch the hole. One hole
per stud. After that, the cellulose will settle with time and you'll end up
with only 3/4 of the wall insulated.

In your case, I'd recommend fiberglass batts and a sharp knife to mold it
around pipes and wires.

That works too - but does not seal air or sound as well as spray
cellulose - which does not work as well as spray urethane foam for the
same job, but costs less and is easier to remove if required for
renovations/repairs/other access.