Insulation
 

Church parsonage ceiling only has 1" of rock wool. NG heat.

Will soon add R19 or R25 batts or blown-in...

What is your experience with blown in vs. batts?

FG or cellulose blown in?

I have tried many different kinds of insulation. The kind I have settled on is Mineral Wool. It has various brand names. I have only seen it in batts. It is about the same cost as fiber glass, has about the same R-Value. But it is much better to work with, as the random fibers don't have the same itching & horrible potential for silicosis, etc (still advised to wear a particle mask). It is absolutely fire proof. I tried putting a sample on an open gas flame of a commercial cook top (35K BTU) for 15 minutes. At the end of the test, there was zero effect of the exposure to heat. It is also a sound absorbing material like nothing I have ever worked with.

By far, my favorite.

-AC

My vote is for cellulose. I like how it performs better the colder it gets vs fiberglass working worse the colder it gets.

I can attest to your comments on the sound absorbing qualities when I experienced it first hand at your house. It was amazing that you couldn't hear the traffic driving by or the kids playing nextdoor until you opened up the window!

Geo

Depends on the air sealing of the site to be insulated. If it's pretty airtight, cellulose is good to go. If there are leaks, roxul is the stuff you should use. It's not as dusty as cellulose and doesn't absorb moisture to a significant amount. Like AC said, it is very sound absorbing and will slow any air leak issues that may exist.

BS!
You forget about or don't know how bulk insulation works. It's sole purpose is to prevent air movement in the insulated space thus eliminating convection heat loss. All bulk insulation materials have a higher heat conductivity than does air but this small additional conductive heat loss is more than offset by the elimination of convective heat loss in still air. Thus, bulk insulation in a sealed volume is only effective in reducing heat loss on a horizontal or upward direction, not in a downward direction, inasmuch as natural convection does not
exist with downward heat flow.
If not careful, one can learn something new every day.

Batts vs Cellulose
 

I did the blow-in cellulose in my attic 10 years ago. I have been disappointed in how much it settles over time (a lot), which I assume decreases its insulation ability. It is also very messy, if you have to go up there and do things.