Drywall Mud after Caulking Seams?

Steven · Post by **Steven** » Thu Jan 12, 2006 7:20 pm

So we put acoustic sealant around the second drywall layer ceiling (there was also some green glue between the drywall)... question is once the acoustic sealant is dry, should we mud the corner seams?

Also, how much NR does two sheets of 5/8" drywall give you? BTW, thanks for the tip on the foam backer rodding!!
Steven

cyeazel · Post by **cyeazel** » Fri Jan 13, 2006 6:17 am

I've read in this forum that mud and tape should be applied between each drywall panel for every layer and caulking should be done only around the perimeter of each layer as a whole.

Post by **kendale** » Fri Jan 13, 2006 6:21 am

Aloha,

how much NR does two sheets of 5/8" drywall give you?

Hope this helps,

Aloha

camistan · Post by **camistan** » Fri Jan 13, 2006 6:47 am

Here's another STC site with info...

http://www.stcratings.com/assemblies.html#01

Here's some other info about finishing/painting a room...

http://www.johnlsayers.com/phpBB2/viewtopic.php?t=4754

http://www.johnlsayers.com/phpBB2/viewtopic.php?t=2185

http://www.johnlsayers.com/phpBB2/viewtopic.php?t=506

These should answer your questions.

knightfly · Post by **knightfly** » Tue Jan 17, 2006 3:21 pm

Steven (nice name, BTW

) keep in mind that STC ratings don't mean SQUAT for actual MUSIC - they were originally used for VOICE isolation, prior to the subwoofer infestation, ANY drums, bass guitars, etc... it's actually possible to build a high STC wall that performs WORSE than a lower STC wall under the wrong circumstances.

For music, LOW frequency Transmission Loss (TL) is what makes the most difference. This is accomplished thru more mass, wider air space between inner and outer leaves of wall, limpness, proper insulation fill, and Constrained Layer Damping (Green Glue) between layers in the wall. (and of course airtight seals)

HTH... Steve

Post by **sharward** » Tue Jan 17, 2006 3:40 pm

I'm beginning to think of STC as a trivial number akin to a car's horsepower rating. Yes, cars with higher horsepower ratings are generally faster than cars with lower ones... But the true measure of a car's speed is -- yup! -- it's actual speed tests -- zero to 60, quarter mile, etc.