cellulose or loose fiberglass insulation for the atic?
I mentioned before, that I have a row house with no insulation in flat roof. JC Construnction quated $2200 to insulate it with celulose. Federal offered the same price but to insulate it with some new form of loose fiberglass. I heard a lot of positive reviews about Federal so I would go with him…
I mentioned before, that I have a row house with no insulation in flat roof. JC Construnction quated $2200 to insulate it with celulose. Federal offered the same price but to insulate it with some new form of loose fiberglass. I heard a lot of positive reviews about Federal so I would go with him just for this. Otherwise fiberglass supposed to resist moisture much better. I also heard that cellulose when wet would release boric acid and this can create corrosive conditions.
Bobjohn,
I’m facing the same problem– cellulose or fiberglass for insulating a crawl space under a flat roof. Have you reached a decision? Who are you using? I’d like to discuss this further with you. Would you contact me at kerryivan@aol.com? Thanks
RE: “Bottom line: fiberglass creates much more carbon monoxide than cellulose.”
Sorry I mean carbon dioxide.
I don’t think you guys are looking at the full picture. When considering the environmental impact of a product it is important to not just look at the product in its isolated form.
My point about fiberglass is broader than whether it has formaldehyde or not. I’m talking about the cradle to grave view.
To make fiberglass this is basically what you have to do:
1. Use heavy machinery to extract it from the earth and transport it to the processing plant.
2. Subject it to high temperatures to melt the sand and turn it into fibers of glass.
This is a tremendous amount of embodied energy. Another huge point is that if you use fiberglass it needs to be made expressly for you. i.e. it is a brand new product that consumes new resources to create. i.e. it is not recycled.
Cellulose on the other hand has very little energy embodiment. If you were crazy you could make it yourself. Just take newspaper, shred it up and spritzer it with a mixture of water and borate.
Cellulose is also recycled. This means that no new resources were wasted to make it. The materials were already there.
On a large scale if everyone switched to cellulose then all that energy consumed to make fiberglass could go to other things, like making cheaper electricity for example.
Bottom line: fiberglass creates much more carbon monoxide than cellulose.
In the isolated state I think cellulose is still a superior product. Inch per inch cellulose has a higher R value. Also, R value means nothing if air is passing through the product and fiberglass lets more air through than cellulose.
Honeycut — they went through the ceiling and the 2 exposed side walls of the extension. No roof puncture at all. I should mention though, that we were already in the midst of a pretty substantial reno on the extension, so those areas were already open. The height of the ceiling-to-roof cavity was rather substantial — approximately 15″ or so. That meant that a huge amount of cellulose was blown in overhead, Bobjohn. The plaster ceiling of our 1909 townhouse (now with some drywall patches)is doing just fine!
Another point about cellulose is its weight. Apparently it is heavy enough so R38 think cellulose is not recomended on ceiling maid of the 1/2″ drywall on the 24″ spaced beams.
I am not sure, how it will apply to the ceiling of the 1910 townhouse in Brooklyn. Anybody has any ideas about it?
Brooklynista, how was it installed? Do they go through the roof?
Genarro–
The problem with fiberglass is not the fiberglass itself (it’s just silica). It’s the formaldehyde with which it’s treated. There is such a thing as “low-VOC fiberglass” and if Joey from Federal is selling you that, then you should be OK.
I can offer a positive review for another company that we used recently to insulate the space between the ceiling and the flat roof of the extension on the house: Brooklyn Insulation and Soundproofing. Check them out at http://www.brooklyninsulation.com/
Our job, using cellulouse, cost $1k. We are very happy with both the way the project was managed and executed and the results.
I can’t seem to find JC Construction. Do they have a website?