10 lbs of material for 4 ft tall super chunk sound right?

Hello, I'm trying to come up with a cost effective way for a DIY super chunk for my current needs. I think a 24" wide x 48" tall corner super chunk would need about 10lbs of Fiberglass to reach 3lb pcf? I plan to compress the needed mass of (in this case 10lbs perhaps?) r30/20 whatever fiberglass into a chicken wire type form for my corner traps, two 4ft tall traps per corner. Does this sound like an effective route? Would a product like the bailed blow in cellulose insulation absorb as well as fiberglass? Thanks, Josh

slowjay wrote:

Hello, I plan to compress the needed mass of (in this case 10lbs perhaps?) r30/20 whatever fiberglass into a chicken wire type form for my corner traps, two 4ft tall traps per corner.

I doubt you will gain a lot, except a lot of additional work. The main cost item of mineral wool is the amount of spinned fiber, hence the price per weight/mass unit (within the same brand and type) Less dense material is cheaper per volume unit, but you need more (and vice versa). It's not completely linear with amount of fiber, since there are some fixed or volume related costs (handling, transport).

The cost of mineral wool (Ruxal AFB) would be about $115 usd per corner. I would need 12 sheets of 2'x4'x2" for a 8ft superchunk. The costs of Johns Manville @ 106 Sq. Ft. of R-13 Fiberglass Insulation is about $27.00. Its density is .8 pcf though. I dont know what the realistic cost savings would be, i cant figure out how to do the math right now. :) -josh

slowjay wrote:

The cost of mineral wool (Ruxal AFB) would be about $115 usd per corner. I would need 12 sheets of 2'x4'x2" for a 8ft superchunk. The costs of Johns Manville @ 106 Sq. Ft. of R-13 Fiberglass Insulation is about $27.00. Its density is .8 pcf though. I dont know what the realistic cost savings would be, i cant figure out how to do the math right now. :) -josh

Doing mental calculations, a 24" wide superchunk would be 12" deep. For that depth, use 4" thick AFB, OR fill teh space with R-13. The 2 should give equivalent acoustic performance. In other words calculate which is cheaper and go that route. Andre