Insulating Green. Whats The Best Option?

ultimatetouch

I am offering the homeowner some options. Foam, cellulose and foam, fiberglass and foam.

Building green what is the best option and why?

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Ultimatetouch
Illinois Remodeling Company, Kitchen Remodeling Chicago, Room Additions Illinois

cleveman

earth

It's readily available.

No need to transport.

No need to process.

Installation is cost effective.

Doesn't break down over time.

Some settling should be expected.

Inexpensive.

Renewable.

You can grow stuff on it.

luxbuildsmall

You need to weigh the costs with the outcome of the project. That being said cheapest and less effective is fiberglass batts ( I won't ever use batts). For a little more money, and in my mind best for the money is wet spray cellulose. More money and probably the best insulation is foam, but you also need to include HRV when you get that tight.

BattleRidge

Foam - best but expensive

cellulose - really good, not as pricey. I've heard this settles tho? But is the most environmentally friendly also. http://www.cellulose.org/cellulose_benefits.html

bats - cheapest but the least performance.

ultimatetouch

The HO wants to up grade insulation. We were going to do straight cellulose. Now were thinking of doing a closed cell foam about 1" thick as a flash cote then cellulose. The other option is all foam which is more expensive.

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Ultimatetouch
Illinois Remodeling Company, Kitchen Remodeling Chicago, Room Additions Illinois

Milhaus

Biobased spray foam. More expensive but made of soybeans. NO CFC, HCFC.

I don't know how the mix and match works. Interesting. Have you done it before?

mark

thom

Nothing that's blown. They say it won't settle, it will. It will settle a lot.

Anyone who ever opens that wall/ceiling has a mess.

If penetrations through the rock aren't tightly sealed, the stuff drifts in forever.

ultimatetouch

I am getting so much mixed advice from insulation guys. some say dont mix. Others say its the most cost offective way and its great. Closed cell foam and open cell. all different opinions.

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Ultimatetouch
Illinois Remodeling Company, Kitchen Remodeling Chicago, Room Additions Illinois

Milhaus

Have you checked out building science.com?

If money wasn't a concern, I'd use open-cell soy based spray foam on every project. For above grade walls, Closed cell is more expensive, and doesn't allow moisture to dry out if it does get into the envelope.

mark
mark

Riversong

Building green, there is only one option and that's dense pack cellulose. Forget the petrochemical foam (as well as the so-called "green" foams which still use toxic propellants) and don't even think about fiberglass (almost worthless).

Cellulose benefits:

• ■ 100% recycled
• ■ very low embodied energy
• ■ completely non-toxic to humans
• ■ toxic to insects
• ■ irritates rodents
• ■ very fire resistant (can use as firestop)
• ■ high sound attenuation (very quiet)
• ■ prevents infiltration
• ■ highly hygroscopic (can absorb 30% of its weight in water reversibly)
• ■ breathes water vapor
• ■ draws moisture away from framing
• ■ if installed properly will not settle
• ■ highest R/inch of fibrous insulations (R-3.8)
• ■ R-value increases as it gets colder or hotter

toolwiz93

Just curious if somebody would like to jump in and describe what they feel is the best idea for a vapor barrier. Our local code is that there just has to be a vapor barrier. Some use kraft-faced insulation and others use plastic. With these different types of "green insulation" what is best? Just trying to get up to speed with the green concept.

Riversong

The greenest vapor barrier is no vapor barrier.

I use the air-tight drywall approach and a water-based vapor barrier primer (Sherwin Williams).



I still can't get away without some synthetic materials, but its minimal. I use Tremco butyl acoustical sealant between framing assemblies and on top and bottom plates when applying drywall as well as around the Lessco polypans I put behind all electric boxes in insulated walls and ceilings.

Since 95% of building envelope moisture comes from air transport and only 5% from diffusion, it's far more important to air seal the inner skin of the thermal envelope. I use the v.b. primer more as a concession to code.

I want my walls to be able to breathe moisture to some extent to help moderate indoor RH and I make sure my outside skin is 5x as permeable as my inside skin to allow drying to the outside during the heating season.

JBBS

Is it normal for cellulose to have pieces of plastic wal-mart bags in it? I just helped a neighbor shoot his garage and I found all kinds of stuff in it! Stuff sure is fire retardant though. We held a cutting torch to it and all it would do is smolder.

toolwiz93

Riversong, I agree with the idea about the air tight drywall system and its ability to stop air flow. So what is your philosophy on housewrap such as tyvek or typar? I am going to assume you have to use something because any exterior finish at some point will allow moisture in.

Norrrrrrrrrrrrm

Did he rent the machine or own it? I have my house gutted to the studs and also want to go green for insulation. I called a company for tight cell foam and was quoted $1,200 for about 600sq ft of wall space. I can't afford that now, so plan B-cellulose.
If it was rented, how much for the day plus materials? What was the procedure? Thanks.

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Norman Sharp
http://www.sharpimprovements.com

JBBS

Norm,

It was the junker machine from bLowes. The machine was free when you bought 25 bags or more I think. His garage is a pole building with sheathing on the interior and exterior so he just filled the cavity. I think I would save up and get the foam. The only way you would be able to blow your walls with the crap machine from the DIY store is to hang the drywall and then blow from the top through a hole the size of the hose. Diry, dusty, slow, PITA. Otherwise you could contact somebody to wet spray cellulose your sidewalls and batt the interior walls. Just my two cents. Im sure somebody who actually does insulation for a living and knows what they are talking about can help you better than I.

Take Care

dutchlegacy

does cellulose actually settle if its sprayed in wet with glue mixed in? How long does it take for the stuff to settle in the stud cavities? does the glue stop this from happening. anybody actually do a side-by-side comparison using glue or spraying it in dry?

Riversong

That's the problem when manufacturer tries to use post-consumer recycled material - it doesn't get separated very well.

I use only National Fiber Cel-Pak. They gave up on post-consumer for that reason and use post-industrial: over-issue virgin newspaper.

Not only fire resistant. You can place a lump in your hand and shoot a blow torch on it. It insulates that well.

Riversong

A secondary drainage plane is important behind the siding. But tests have demonstrated that good old rosin paper and 15# felt actually work better.

Because they're shingled in 3' wide runs, there's more opportunity for water to drain if there is condensation behind it.

They are both hygroscopic, so any condensation from inside can wick through and be released through the siding (if the siding is not impermeable).

If there are any air voids between synthetic housewraps and the sheathing, and moisture migrates through the walls from inside, it can condense on the backside of the housewrap and get trapped, wetting the plywood sheathing which makes it more permeable to moisture and continuing until there is a serious moisture problem.

Riversong

If installed properly, cellulose won't settle regardless of whether it's installed damp, blown behind insulweb, or blown into closed cavities.

The only function of the dampening is to allow it to freestand in an open wall cavity prior to drywalling. The insulweb is becoming the standard for new construction, though I typically blow into closed cavities after the drywall is up.