blown fiberglass or cellulose, which one?

[John Daugherty]

Hello,

I very shortly will be insulating my attic space (new construction). I have spoken to a few people about using blown fiberglass or cellulose. I have learned one thing, the fiberglass people bash the cellulose and vise versa. It’s gotten to the point I don’t know who to believe. Could anyone give an unbiased opinion? What are the advantages/disadvantages of each?


Thanks

[Richard Gillespie]

I built my house 17 years ago. I had blown fiberglass insulation put in the ceiling. Glad I did. My roof started to leak after 14 years in several places and had to be replaced. I wonder how much mold I would have had in the insulation if it had been paper. On top of that the paper would have absorbed the water and became very heavy before the leak would have shown through.

Just my .02.

[Cecil Arnold]

Richard has the answer. You don't want cellulose, it degrades and can give you a dust problem over time and is treated with borax.

[Bart Leetch]

Cellulose insulation

I used to install insulation professionally. We used to vacuum out cellulose because it loses its fire retardant ability after a few years. I literally lights off like a torch. Several times we had cellulose vender's come to try & sell us on cellulose insulation & we always showed them our test of aged cellulose insulation by taking some out of the vacuum truck hopper & dropping a match on it whoosh it was gone their embarrassed look & answer I guess I don't have much to sell do I was all we ever heard.

If you value your life, home, or shop stay away from cellulose.

The only proof of fire retardant abilities of cellulose is being able to take old & I do mean old 25 - 35 years old or older cellulose out of an old building & try & light it. No one has provided this proof to me yet.

I won't accept any other proof & you shouldn't either.

Talk & words of assurance are cheap your life & home & shop are not.

I have had insulation contractors on other forums E-mail me & tell me of their similar experiences. One told me he would only install cellulose if the person wanting it would sign a release that obsolved the contractor of all responsibility if there was a fire.

[Jesse Merino]

Well, the only thing I can say is that fiberglass is good if you pile it on... a good R-19 faced in the rafters, and then R-25 batts over that... Its what I put in my attic

The thing about "borax" is that it prohibits mold... Its only benefiet. (Of course, I dont know about the degredation factor, on how long the chemical lasts, but, like any drug, or chemical, each thing has a shelf life, and loses its effectiveness after so many years.

Besides, I dont like the cellulose compaction rate, after a few years...

All insulation, will have "dust", after years of being up there... It comes with attic ventilation, the dust works its way in, and there is no way around it.

When I took out my "cellulose" from the attic, in the house I now lived in, I personally vacumned all the rafters, chimney and everything in the attic, before putting in the fiberglass insulation. Been up there a few years ago, and it looks like there is coal dust everywhere, laying on top of the fiberglass... (It could be, because I live only half a block from a highway, and dust comes from there, as well as a dusty road a block from me too....but, you get the point...it will work itself in, when you have vents in the roof, and every roof, has to have vents!)...

So, this is my two cents for what its worth, and a wee bit extra for the collection plate...Jesse

[Reg Mitchell]

I built my house 4 yrs ago. I looked at both of them.What i fould ws the cellulose has a flame retardent on it. When it drys out it falls from the paper and can give you somem health problems. I did the fiberglass thin and don't regret it

[John Daugherty]

Thanks for all the information. I'm going with fiberglass!

[Hunter Wallace]

Hey, what a timely post this is....

My neighbor, an oldtimer who only winters in the house next door
to mine, had some leaking from a water pipe and had removed some
portions of plaster & lathe to make repairs. He told just last fall that
about 7-8 years ago he had a very reputable local insulation company
blow in fiberglass insulation, but when he went to open up his walls
the fiberglass had compacted about 2' down in the 8' high walls. He
had opened up about 4 stud bays and each and every one had
settled at least that much. I know it'll cost about 5 times more, but
I think I may go with Icynene...a foam that is more like marshmallow
in your walls than the heavy (super expanding) urea formaldahyde stuff.
I hope this isn't rain on you parade...