blown in cellulose insulation?

[tinetine'sgoat]

We are interested in blown in cellulose insulation in the new house and have heard alot of good things. The only major downside we have heard is that it is next to impossible to add outlets or do in the wall work after it is in. Do any of you have any experience with it, pros or cons that we should know about. The guy who priced it to us said about 2000 installed.

[uncle Will in In.]

We had it blown into our walls and attic about 30 years ago. Lots of old houses were getting it blown back then. Almost no one do it here now. The drilled holes in the siding to do it. Biggest problen I know of is it doesn't always fill the spaces between the studs. It can catch on anything such as nails from the siding. It bridges over and leaves an empty space. No complaints about the attic. Where they can see where they are puting it, it does a good job. In new construction, I woud use insulation that I could put in during construction.

[copperkid3]

Have done a number of houses (7 at last count) over the years with blown-in cellulose insulation into old houses; drilling holes in the outside siding to gain access. Also going into each attic and blowing in a thick layer across the ceiling joists. The current (and hopefully last) house we are presently living in, was done with a contractor who specialized in blowing in with a wet spray added, so that each wall joists was literally plastered with a papier mache mixture that was then allowed to dry and then "shaved" off flush with the 2 x 6" studs; fills ALL the space and thus NO voids. If you or anyone else go this route, make sure to get your electrical and plumbing in that has to go in first. We then added about 24 inches to the ceiling by renting the equipment to blow it in ourselves! Keeps the house nice and toasty; holds the heat in and the cold out.

[SolarGary]

Originally Posted by tinetine'sgoat

We are interested in blown in cellulose insulation in the new house and have heard alot of good things. The only major downside we have heard is that it is next to impossible to add outlets or do in the wall work after it is in. Do any of you have any experience with it, pros or cons that we should know about. The guy who priced it to us said about 2000 installed.

Hi,
Cellulose is very good insulation.
In loose fill it has a substantially higher R value per inch than fiberglass loose fill, and it is not subject developing circulation currents within the insulation that can cut the effective R value in half under cold conditions.

Voids in cellulose blown in the walls should not be a problem if the installer does it well -- i.e. uses two holes per stud cavity, and dense packs the insulation.

There is some good material on insulation here:
http://www.builditsolar.com/Projects...htm#Insulating
I think that the Harley book (Insulate and Weatherize) is particularly good -- its my bible.

You might want to consider sealing up all of the plumbing, electrical wire and light fixture penetrations that come from the living space into the attic BEFORE you blow more insulation in. Its a lot easier to move 6 inches of old insulation out of the way to do the sealing than to move 6 inches of old plus 10 inches of new
Also a good time to seal up and insulate any ducts that go through the attic. Use duct mastic to seal duct joints (not duct tape which falls apart in a couple years). This article says that in a typical home 30% of the hot air gets lost to leaky ducts:
http://oikos.com/esb/28/duct_losses.html

Gary

[tinetine'sgoat]

Thanks for the answers!! I'll be passing all this along to dh tonight so we can talk it over!

[TechGuy]

Originally Posted by tinetine'sgoat

We are interested in blown in cellulose insulation in the new house and have heard alot of good things. The only major downside we have heard is that it is next to impossible to add outlets or do in the wall work after it is in. Do any of you have any experience with it, pros or cons that we should know about. The guy who priced it to us said about 2000 installed.

FWIW: My concern with Cellulose is that if it get damp or wet it will likely lead to oders in your home. Plus if a fire did occur it would Although cellulose insulation contains fire retardants its probably still combustable if it gets hot enough. Plus you might consider all the chemicals that are added, pesticides, rodet repellents, etc.

My choice would be blown in fiberglass over cellulose and expanding foam.

[Macybaby]

I hate the stuff!!!

But I've been removing it all from an old house that had it blown in maybe 30 years ago.

It had settled enough that there were lots of voids in the wall, and it was so packed in the ceiling too. People forget you need to periodically fluff it up in the attic.

Cathy

[tinetine'sgoat]

The stuff that he quoted me he said he sprays with water to activate the glue? Is that the same cellulose?

[thoshead]

The product that he has quoted is refered to as "stablized cellulose". It is a much better product than the type used in years past. It also has excellent sound deadening properties and is a natural pest repellent due to the binder used in the spray. It is also treated with a fire retardant product (as required by national building codes) for safety reasons. I have used this on both residential and commercial projects with wonderful success.

Thos.

[SolarGary]

Originally Posted by TechGuy

FWIW: My concern with Cellulose is that if it get damp or wet it will likely lead to oders in your home. Plus if a fire did occur it would Although cellulose insulation contains fire retardants its probably still combustable if it gets hot enough. Plus you might consider all the chemicals that are added, pesticides, rodet repellents, etc.

My choice would be blown in fiberglass over cellulose and expanding foam.

Hi,
I've took a few handfuls of 5 year old cellulose from my attic, and held my propane torch on it. You get some initial small flames in the area right where the torch flame hits it. These quickly go out (with the torch flame still on them), and the charred area does not spread out from the immediate area of the torch flame. Not very scientific, but my impression was that the stuff is more fire resistant than the wood framing of my house.

As far as I know, the only thing added to the cellulose is the borates that provide both the flame retardant and rodent resistance.

Gary

[mightybooboo]

My Dad used to sell it.He would take a little box,about 3X5 inches and about 1.5 inches thick.He would pack it tight with insulation.

Then he would take this little brick out,hold it in his hand,and melt a penny on top with an acetylene torch.His absolute best customers were firemen.We never owned a house that didnt have it.BTW,the old copper pennies melt easier

So trust me,that is a GREAT fire retardant.

BooBoo

[Liese]

Everyone has provided a lot of good info on this but are there any special tricks to doing this on a house that is on a crawl space? We have just put in new windows (Ultrex) but the drafts are actually coming up through the walls; plaster on lathe covered with new wallboard by a previous owner. The wood siding was nailed up directly to the studs and is now covered in thin foam board insulation and vinyl siding. Coming from Michigan it is interesting to me to see how "thinly" they built older homes here in NC. Must have had lots of cheap heat then - if there ever was such a thing! Liese

[debra in ks]

[QUOTE=TechGuy]FWIW: My concern with Cellulose is that if it get damp or wet it will likely lead to oders in your home. Plus if a fire did occur it would Although cellulose insulation contains fire retardants its probably still combustable if it gets hot enough.

Don't worry about combustability. My dad blew cellulose insulation for 40+ years. One of the things he would do for prospective customers was grab a big handful out of the bag, lay a penny on it and melt the penny with a blow torch...insulation didn't burn, but the penny melted. Loved that demonstration when I was a kid!

[fantasymaker]

Are we talking new costruction? if so Id do duoble wall construction better insualation and easyer to run wireing and plumbing too!

[Ninn]

My DH used to install this stuff for a living-both wet and dry spray. Wet spray was better for filling large gaps, too. He says all in wall work must be completed prior to installation, as it adheres to everything in the wall. It would be 3 times the work to go back and carve out niches for outlets and wires. Probably 3 times as expensive, too. The 2000 estimate you got is a good price-his old boss quoted us that much to do our trailer!!

[highlands]

I had this done back in the late 1980's on a big old house. Three problems:

1) The holes they drilled are ugly marks on the siding. I never would have let it be done if I had known how ugly it was going to be. And I'm not that picky.

2) They didn't really fill the walls all the way and it's very hard to check this at the time. The result is come winter you discover where they didn't do the job right because there are cold spots on the wall where condensation forms.

3) The cellulose insulation settled, a lot. Now it is halfway useless.

I do not recommend it. If it were my house I would probably go with blown in foam-in-place insulation and probably do it myself so I knew it was done right. There are environmentally friendly foams and the foam is a far better insulation. Do a small project first.

-Walter
in Vermont
http://SugarMtnFarm.com/blog

[Ramblin Wreck]

In one house I built, I blew the cellulose insulation in the attic myself. Home Depot sold me the insulation and let me use a blower for free. I had to put down a deposit which was returned when the machine was returned.

Edited to add: It saved me a few bucks to do it myself.

[TechGuy]

Originally Posted by highlands

I had this done back in the late 1980's on a big old house. If it were my house I would probably go with blown in foam-in-place insulation and probably do it myself so I knew it was done right. There are environmentally friendly foams and the foam is a far better insulation. Do a small project first.
-Walter
in Vermont
http://SugarMtnFarm.com/blog

The issue with foam that I see is that can outgas some nasty chemicals during a fire. The spray-on foam also adheres to everything it touches. This could be problem if maintaince needs to be done later (ie leak pipe, additional electrical/cable/data lines). Perhaps a double wall or barrier (suggested by fanstasy maker) or areas with utilities might be an option, but I suspect this would make construction more complex and expensive.

I still thing blown in fiberglass may be the best choice. Although I have to research if settle like blown in cellulose over time.

[mightybooboo]

I dont know about fiberglass,Im hearing that can be real bad for your lungs.Would hate to find out in 30 years its the new Asbestos.

BooBoo

[TechGuy]

Originally Posted by mightybooboo

I dont know about fiberglass,Im hearing that can be real bad for your lungs.Would hate to find out in 30 years its the new Asbestos.
BooBoo

Breathing in cellulose laced with boron and other chemicals is also hazardous to your health! Thats why rodents avoid it. Once the fiberglass is installed behind drywall there is no danger of inhaling it since the particles are trapped and are too large come airborn for very long. On the other hand the fine cellulose particles can remain airborn for a considerable period.

FWIW: The dangers of Asbestos are over blown. The people that got sick were workers that handled unprocessed fibers every working day for years. A simple filter when working with it would have prevent the majority from ever getting sick, but back in the day no one bother to think about it protecting their lungs.

More people get sick from mold and mildrew than by asbestos and Fiberglass.