can someone help identify this acoustic "sound deadening board" material?

[John_Toolbox]

I acquired some of this "sound deadening board", it was used to insulate an office from a noisy shop. The boards are 2" thick, and made from a fibery type material. Very rigid and very heavy. I'm trying to figure out what this stuff is called so I can do some research on what the best use of it is for my studio.

Does anyone know the name of this product, or anything about it's performance?

Here are some pics of what it looks like:

http://pic100.picturetrail.com/VOL10.../402960571.jpg

http://pic100.picturetrail.com/VOL10.../402960569.jpg

[Emcha_audio]

I've been looking through the company's I know of, and none seems to be using this kind of product, so I'm at a loss. Sorry.

[necjamc]

That looks like the stuff they use in school auditoriums. Couldn't tell you what it's called. But I know I've seen it.

[Jay_uk]

It looks like compressed straw, so thats what i Googled... result is.

it could be this Stramit ... or ... Straw board, straw mixed with cement and used for flat roofs/decking.
http://epdm-rubber-roofing.co.uk/201...ing-osb-v-ply/

[John_Toolbox]

Jay UK saves the day! This is exactly what I needed to know. This stuff will be perfect for what I intend to use it for, not only is it designed as an acoustic barrier, it also apparently has an R value of 12, so it will solve both the problem of rain/plane noise and also add some much needed insulation to a currently underinsulated roof.

Interesting reading about how it's made, there is no glue, it's just heated up straw, and the resins in the straw are what bond it together.

[Jay_uk]

It looks an interesting product, hope it works out for you John.

[John_Toolbox]

So far, with only 1/4 of the ceiling, and one window covered ,and no sealant of any kind, I have reduced the ambient noise in the room by 10db! (there are 2 central ac units near that window) Very excited to see how it works out once it's all installed.

I did some more reading, the R value is somewhat questionable. Apparently the strawmit brand is advertised to be R12, however some other sites refer to strawboard being R3 or R6... But not specific if they mean R3 per inch, making a 2 inch panel R6, or if they really mean R6 per inch, which would explain the strawmit being advertised as R12 for a 2 inch board. Or maybe strawmit is special. No idea what manufacturer made the stuff I have, it's not marked anywhere that I can see, one side has been painted blue, but I'm pretty sure that was from the previous installation.

This stuff is heavy as hell, once I get the rest of the pieces for the ceiling cut I will probably rent a drywall lift to install them.

[Jay_uk]

Okay..sounds promising.
Where does the fire retardant spec come in, if its just heated up ?
I have not read the spec but iirc, i saw somewhere that cement was involved.. thought thats what made it heavy.

[John_Toolbox]

It has a 1 hour fire rating... Meaning it will eventually get burninated, but will slow down the spread of the fire.The article you linked to suggests it is mixed with cement, however all of the other ones I've read suggest that the "glue" is the resins that are in the straw.

When I cut it there are not any funny smells like you get from cutting osb or plywood, which seems to support the idea that it doesn't use any chemical glues.