cellulose vs foam insulation

[KYErik]

Here's a random cellulose question- when they spray the cellulose onto the wall between studs (before you put up the drywall) what makes it stick there (and not just fall out)?

Is it wet (with water) or is it some special non drying chemical or glue that makes it stick together? I would think that if it was wet (with water) the dampness of it would cause the studs to mold and rot when the drywall was installed and trapped all of the moisture in the stud cavity.

I used cellulose in my garage attic and I am very impressed with how easy it was to blow in and at how well it works.

 

[Diesel-ME]

Here's a random cellulose question- when they spray the cellulose onto the wall between studs (before you put up the drywall) what makes it stick there (and not just fall out)?

Is it wet (with water) or is it some special non drying chemical or glue that makes it stick together? I would think that if it was wet (with water) the dampness of it would cause the studs to mold and rot when the drywall was installed and trapped all of the moisture in the stud cavity.

I used cellulose in my garage attic and I am very impressed with how easy it was to blow in and at how well it works.

Wet spray cellulose uses water and an adhesive to help stick to the framing members. Some of the builder mags (as I recall the Journal of Light Construction) have reviewed this stuff recently. I'm not sold on it personally. For one thing it would really hold up the building process waiting for ALL the moisture to evaporate prior to vapor barrier and sheetrock. However, despite my skepticism, the wet-blow proponents say it is an efficient and safe product. I does pack really tight - have to give them that.

Of course, unlike loose cellulose, the homeowner can not run down to Lowes/HD and borrow a blower and self-install the wet stuff.

There is another way to use cellulose on sidewalls in new construction. You can install fiber-reinforced plastic sheeting on the empty stud bays and then blow the product in.

Check out this link to an interesting related article.

~paul

 

[Alan L.]

I put low-density foam in every wall or ceiling adjacent to the outside (including cathedral ceilings). I chose not to do the entire envelope and went with blown fiberglass in the horizontal ceilings - R50. Everything was sealed up tight, the attic has a radiant barrier and good ventilation with ridge vents.

First month electric bill showed we used 1700KW in the month of June compared to > 3000 last year. Last year we were in 880 square feet, this year 2200. Prior year had the power to run the water pump and hot water heater, then new house has a propane tankless water heater and the well pump remains on the old building meter. Also, my units are Trane 16 SEER 2-stage whereas the building has a 7 year old 10 SEER unit.

I think its going to be great. I have a section of roof inside an insulated storage area within the attic. When its hot outside the foam surface on the underside of the roof is cool as a cucumber.

All of the insulation together was $8500 which was about 3 times what conventional fiberglass would have been.

The value of the foam is its true R-factor in all conditions, and the sealing characteristics.

I'm sold on foam, although not sold on the entire envelope concept as I couldn't see how cooling an entire huge attic could be a good idea, even considering the ductwork and air handlers would be inside the conditioned space. I could not find a single study that concluded this would save energy vs having good ventilation and ceiling insulation.

 

[crbr]

I installed this in my house about 7 years ago. I am pleased with the ROI.

http://www.icynene.com/InsulationSystem.aspx

 

[heehaw]

i know anyone can say anything: but according to a fairly well know architech here in Arkansas: he has been involved in over 300,000 homes that use cellulose, and there has never been a single documented case of mold or mildew, unless there was a water leak. i am pretty sure, he says there is no need for the vapor barrier or the house wrap if you use cellulose: which saves some $$$: fireproof, rodent proof, roach proof, and keeps wind from blowing thru the electrical outlets, thats the other plus's he says about cellulose.
heehaw

 

[Diesel-ME]

i know anyone can say anything: but according to a fairly well know architech here in Arkansas: he has been involved in over 300,000 homes that use cellulose, and there has never been a single documented case of mold or mildew, unless there was a water leak. i am pretty sure, he says there is no need for the vapor barrier or the house wrap if you use cellulose: which saves some $$$: fireproof, rodent proof, roach proof, and keeps wind from blowing thru the electrical outlets, thats the other plus's he says about cellulose.
heehaw

I don't know about acceptable building practices in Arkansas, but for readers in the north, you ABSOLUTELY and unequivocally need a vapor barrier AND house wrap when using (dry-blown) cellulose.

Heehaw, is your architect friend speaking of wet-blown cellulose? Perhaps there are differences in acceptable use as compared to dry-blown...???...

~paul

 

[heehaw]

all they put in the walls around here is wet-blown: new construction where the walls are open. go to dougrye.com and you can read some of the stuff the architect has written about building houses with low utility bills etc.
heehaw