For The Builders?

joasis

As some of you know, I recently added blown cellulose to our in house bag of tricks, and then decided to turn it over to my son, and let him grow a business. Well, while doing a lot of research, it comes across that there is still a lot of opposition to cellulose, so I am wondering what others, like me, actually are thinking and doing. I have usually batted the walls and blown the attic spaces. A few we have wet sprayed the walls, and that is what I will do from now on.

Now this can be done with fiberglass or cellulose, and I am getting the idea cellulose has a bad rap in some areas.

So here it is:

Cellulose settles, but when wall sprayed with adhesive, it stays in place.

Completely fills all voids when applied correctly.

Is a "green" material, 100% recycled paper.

Is treated for insects, and mice do not tolerate it either.

Is a fire retardent, rated as well.

Research shows that as it settles over time in an attic, if undisturbed, the insulation value changes very little.

Great sound control.

Mold and fungus resistant.

It has superior perfermance over batted fiberglass and blown fiberglass in wall cavities.

Now fiberglass can also be blown or sprayed, and what I heard from a few suppliers is that many people are resistant to cellulose because of bad press....

So what have you guys been using and why?

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tcleve4911

We recently did a nice small addition in Shelburne using Spray foam.
One advantage was we could spray the walls & ceiling and not have to apply drywall to hold in in place.
2nd was the wall to rafter connection at the top plate is always a concern for getting enough insulation value where the space is only 3-6". 4" of foam gave us an R-30 at the top plate.
Cost was the same as "Dense pack " cellulose.
No drafts, no settling, quiet.

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Back in Maine
Dubbin' Around
Doin' good stuff ......

thom

I've posted before on this subject. I won't use cellulose again. I used it on my own house (ceiling only) and that was a mistake.

I bought 18", I got 3. It's not simple to verify. With batts, it's pretty obvious.

Because I didn't get the full depth, pipes in the ceiling froze and burst (Christmas day). Batts would have laid over the top of the pipes putting them on the warm side. Inadequate depth meant the pipes were on the cold side. This was in a location that would have been tough to verify.

If there is ever a roof leak that requires sheetrock repair, blow-in is a PITA.

If you ever want to add speakers or something in the ceiling/attic space, blow-in is a PITA

If you ever want to access the insulated space, blow-in is a PITA.

If you don't seal your ceiling penetrations (electric, ducts, etc) you will get a never ending dusting of insulation.

Blow-in requires trusting without the ability to verify. Blow in makes later repairs/modifications more difficult/expensive. I made that mistake once. I won't do it again.

As for wet in walls? Why do it? You're adding moisture then closing up the walls. Maybe it's completely dry when rocking, maybe not. Why take that chance?

Will it sag in the walls? They say no, but that's what they said 30 years ago and we know they were wrong. Why take that chance?

There are other alternatives (batts for example) that overcome my objections to blow-in. There is no appreciable difference in cost. For the minor performance gains (actually I believe there is a performance loss due to skimping on materials) there is no good reason to do blow in.

Just my $.02

tcleve4911

Hey Thom- so what do you use- fiberglass batts? Ever done the foam?

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Back in Maine
Dubbin' Around
Doin' good stuff ......

house bldr

We always blow the ceilings with cellulose and batts in the walls.I feel the blow in provides a tighter seal in the ceiling and the lumber yards allow free use of the blower with insulation purchase.Batts in the wall just because we would have to sub it out for anything else.I am intrigued with the idea of trying spray foam,everything about it sounds good,execpt the price!

mdshunk

As a professional "crawler arounder of attics", I think I can comment. New construction in my area is almost exclusively batts in walls and blown in attics. Cathedral ceilings are still batts, though.

joasis

I too like the idea of spray foam systems, but the initial cost of the equipment set up is frightening...28k is about normal for a contractor's set up...material cost is 50 cents and up a board foot, and I don't know why they are using the bd/ft term as opposed to sq/ft, except the material is placed based on so much per pass, so I suppose you would have 2 bd/ft for say, 6 or 8 inches of expansion.

I am sending the boy up to Fiberlite in Joplin for 3 days of training on Monday, doing set ups and wall spraying. Then he will see what it is really like.

The issues you addressed thom would seem to point to a major quality issue...like none. If you paid for 18 inches and got 3, you got ripped off. The dust issue doesn't worry me since we caulk the electrical boxes anyway, and frankly, I have been blowing the attics for a long time, and have had no real issues. I agree, it is a PITA if you do anything, like my son did by stepping through the ceiling, but that is why I have a big shop vac. I hate working with fiberglass and refuse to blow it...it really sucks.

But this is why I posted this..to see what others were thinking...energy savings is what we are shooting for. If the demad growns, i will probably go for the spray foam system, to cover all the angles.

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thom

In response to tcleve, I use batts exclusively, walls and ceilings.

I live in a dry and moderate climate (New Mexico) where our issues are not significant as others.

One issue I don't understand with code, we must either use sill sealer or caulk our sills. Makes sense with siding which allows leakage but we uwe stucco. There is virtually no infiltration through walls with stucco except at penetrations. Even at penetrations, any leakage is a fraction of what it would be with siding.

bryguy100

I will conquer all of the objections with counter reactions on fibreglass and batting that would put it to shame!!!

Halo

I have been increasingly using more wet-blown cellulose. While moisture is certainly a concern, it easy to monitor and deal with as neccesary. In my opinion there is nothing that can match its effectiveness in dampening sound.

Certainly in a remodel or retrofit situation the logictics can be a pain. But personally I will put up with a lot (including expense) to not have to deal with fiberglass in any way shape or form.

Like anything, the installer/installation is key.

TempestV

What I've seen on the last couple houses I've worked on is a thin layer of foam, maybe 2" in a 2x6 wall, followed by fiberglass batts. the idea with the foam is that a thin layer like that seals from drafts, but because it is expensive to blow the whole wall full, fiberglass is then put in on top of it. Blow in for attic spaces and some walls for sound proofing, most sound walls are fiberglass insulation.

GregS

Everything new here is batt walls and blown attics. Don't spray the walls, you'll p!ss off guys like me who have to fish wire post construction

joasis

We blow it all, and where we have been forced to use batts, we now net and blow.

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Custom Builder

I currently use all batts. Even in our largest home under construction which is 1.5 mil they still specified batts. From what I understand even if the cellulose is treated it still sags and will still spawn mold like rabbits when wet. I know they state otherwise, but most are yet to believe it. In a 2x4 or 2x6 wall it doesn't have any more R value than batts. I personally don't think it "fills all the gaps" much better than batts. The batts guys caulk and foam all seams before installing. I think you're better off spending the extra money on better windows and doors.

joasis

We had to open up some walls that were blown 6 years ago, and the insulation was still as tight as the day it was sprayed in...When it was installed originally, it was the first time I saw "wet blown" cellulose, and I too was skeptical. The product we use is not only treated with borate, it also has a corn starch added that gives it a "glue set" when applied.

I have had a few samples of cellulose in a bad in a shed, wetted a few times, and one that gets wet everytime the wind blows, and no mold yet.......

As for the comparable R values, I think research is continuing to erode away the myths of fiberglass....and as cellulose settles in a loose fill, like an attic, it actually tightens as an air seal, and does not loose the insulative value. Lots of material out there in product research and studies.....we do not use fiberglass, ever.

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