Insulating my attic

[midwestcoast]

I am considering using Refletix as the first layer (staple it to the joists?) in my attic insulation as both an air and vapor barrier and to contain the next layer of cellulose in the event that we renovated the bedrooms, plaster and lather, it would contain the loose fill.

Any critique of this idea is welcome.

If you're installing a vapour barrier in the attic you want it to be below all insulation. Otherwise vapor can get traped & condense in the insulation below the barrier. Mold & ceiling damage possible.
If you're talking about insulating at the roof and not venting below the roof then that would be the right place for the Reflectix, but I'd be very concerned about any water leaks getting into the cellulose & no way to dry with a vap barrier in place
To get the R-value in limited thickness of just the joist bays I'd be looking at spray foam (much less worry from leaks and effective air barrier too).

IMO radiant barrier is effective for reducing radiant heating from hot roofing in summer. Needs an air-gap on the hot side or it's useless. Reflectix also gives some insulation from the bubbles, but it's an expensive option if you have a lot to cover.

Yes, I was thinking in term of using it on the warm side. Spray foam would be great but the it would be stuck to the lathe and we do want to renovate two bedrooms below. We can't do them first because we'd be pulling down a filthy mixture of rock wool, a little vermiculite (asbestos) and mouse turds on our heads. Catch22 going on here for sure. No venting possible here anyway, the house is post and beam.

Can you think of a cheaper barrier to lay down that will contain the loose fill if the plaster and lathe were taken down in the future?
Something sturdy, I've thought of house wrap, landscaping fabric - more ideas appreciated

I'm not sure if I understand exactly. Are you planning to remove the old insultation anyway? Why not remove it, then renovate & instal barrier, then loose fill last.
The vermiculite is a whole topic unto itself. You sure on that?

 

[szmaine]

"I’m not sure if I understand exactly. Are you planning to remove the old insultation anyway? Why not remove it, then renovate & instal barrier, then loose fill last.
The vermiculite is a whole topic unto itself. You sure on that? "

Yes, remove it, hepa vacuum everything, reinsulate..

Can't do that and renovate two bedrooms before the next heating season.

Yes, the previous owner was kind enough to leave behind two mint-in-the-bag Zonolite vermiculite insulation = Libby, MT vermiculite - they poured it down the slope ceiling portion of the roof (cape style construction) and other random nooks and cranies.

Sorry, RNLA, hijacked your thread...

EDIT: The roof needs to be redone too, then we will be able to get the vermiculite out of the sloped ceiling FROM THE OUTSIDE and have spray foam done on the slopes. Sorry, these are the contortions of someone who cannot afford to hire contractor and have it all done up at once.

 

[semipro]

Anyone know any supposed benefits of it overfiberglass or cellulose. I say supposed because from what I see insulation manufacturers put out almost as much junk science and half-truths as insulation.

According to an independent study (which I can't recall the source for) cellulose's R value holds up better as temps drop.

It may have been this article:
(broken link removed to http://www.finehomebuilding.com/how-to/articles/blown-insulation-for-attics-fiberglass-vs-cellulose.aspx?ac=ts&ra=fp)

I get the magazine but can't access the article online without paying.

Thanks, I had read the study that came from (Oakridge National Lab I think is original source) but I meant supposed benefit of polyester over glass or cellulose. I take it no itch or dust is the answer.
Tyvek suit w taped gloves & dust mask for FG install or very good dust mask (like sealed 1/2 face respirator type) for cellulose would be my choice over doubling the cost if this is a place where once installed you don't have to mess with it any more. Working in that PPE is hot & annoying though.

I agree on the PPE. I have yet to find a decent particulate filter mask that fits well and doesn't fog safety glasses....very frustrating.

 

[RNLA]

Yeah, I had wondered about yous guys takin over? That is OK I am enjoying checking back to see what others are saying about this. I will be doing the attic of my 1941 house this summer or fall to make my wood stove do some real heating. If I am able to get the Polyester batts I will go about a total of R-30. The existing insulation is the equivilant of R-8 shaved wood, imagine something that looks like steel wool... Needless to say we are a bit on the drafty side right now.

 

[szmaine]

Wood shavings? That is very unusual...
One room we renovated here had some stuff that look like sawdust sandwiched between very leathery fealing paper, as if it had an oily coating like tar paper only not black - I believe the name on it was "Balsam Wool" - funky stuff.

I'm pretty sure I will try the rock wool batts as I mentioned, fiberglass doesn't bother me much- the old loose rockwool I've removed from here I could lie in without any discomfort.

 

[RNLA]

I thought about the rock-wool and was told that it has a similar feeling and irritant capability as fiberglass. Some have said as you did that the rock-wool doesn't bother them. My goal is to have comfortable access to the attic as well as reasonable R-value. The other part of this project is the floor or crawl space. We had the vapor barrier changed out as there had been several dead animals down there; that was money well spent on a professional company. So to the point I was thinking of using styrofoam boards in between the floor joists. This will be expensive too but I like the thought of the insulation not hanging down, even after a professional install I've seen too many crawls that just had crappy workmanship. I am guilty of doing things to far over kill but it is our home and we have to live here and I have to repair it if I can't afford to call a "Professional" %-P