Have had 2 estimates to insulate my attic - one recommends cellulose and the other recommends fiberglass. The fiberglass is actually cheaper, but the lady who gave the quote for the cellulose insulation seemed more like she knew what she was talking about. She said due to the humidity in Houston the cellulose works better and won't deteriorate as quickly. Any advice?

Fiberglass deteriorates? It might settle.

Cellulose is organic. It may settle slower, but it will deteriorate in the long run...but with either product, we're talking decades.

Cellulose is organic? It's recycled paper treated with pesticides and fire retardant chemicals.

Assuming your talking Blown Fiberglass vs Cellulose, the Cellulose will most likely settle faster as it is much heavier than the fiberglass insulation. It also absorbs more moisture, but that's really only a problem if you have a leak or animals in the attic pissing in a certain spot. Fiberglass sucks much more to deal with, both itching and breathing in if you do any work in tha attic. Cellulose has a tendency to be really dusty when disturbed, but not near as irritating.

All in all, if I were just blowing the **** in the atttic and never planned to mull around in the ****, I think Fiberglass is a cheaper and better option.

EDIT: An added FYI, I was an Insulation Contractor from '99-'02, and have been in construction for 14 years.

[This message has been edited by Catch (edited 4/26/2012 10:11a).]

Another thing to consider. What is currently in your attic? Do you have old Batt insulation? If so, you really don't want to retrofit your attic with cellulose on top of fiberglass. It will settle much faster because of the weight pushing down the existing fiberglass batts, rendering the R-value of the batts useless. Blown Fiberglass will just set on top and add to the value of the current R-value.

If youre going to live there forever, or plan to, then I would go with spray foam.

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If youre going to live there forever, or plan to, then I would go with spray foam.

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I'd recommend the **** out of that for new construction, but retrofitting an attic isn't really feasible.

Catch, thanks...what I have in there right now is about 1-1.5" of cellulose. Would the blown in fiberglass be a good option in that case?

If that's the case, you can use either without worrying about losing existing R-value. Might want to stick with the cellulose just to remain consistent. That's what I would do, unless I was really trying to save money.
It'll also probably be neater job in the long run.

Though I guess another thing I should ask, What kind of R-value are you looking to get and how deep are your joists?

What kind of insulation is best for a new metal building / barndominium?

New metal building? Depends how you're finishing it out. If your covering everything up inside, I'd sprayfoam the exterior walls and roof deck.

If you're leaving everything as exposed structure, I'd go with vinyl faced fiberglass insulation. Installation method being dependant upon the building itself.

Thanks for the info. My plan would be to cover everything up on the inside. Just curious, do you know what the energy efficiency is like for a metal building?