Sound Dampening for Packaged Rooftop Units

[KenRad]

Does anyone have a spec for sound dampening material inside of a roof curb for a packaged unit? I have a 30-ton and 40-ton unit that I'm installing over an office. The roof is a membrane over corrugated metal. I want to put something on top of the corrugated metal decking inside the curb, to minimize noise transmission to the decking, and to the return plenum below.

Would fiberglass wall insulation do the trick?

---KenRad

 

[cme]

I would suggest some MASS below the unit ...... I have been putting some layers of that "cementuous board" in the roofcurb ....... its a substitute for drywall in bathroom/shower areas .......... I would rate that 3rd only to concrete (#1) or gravel (#2) ..... I've used concrete below compressors for large units too and sometimes I put them on dunnage, elevated

 

[KenRad]

cme,

The only problem with what you suggest is weight limitations; the corrugated roof decking inside of the roof curb spans between the bar joists that are supporting the curb, so they won't hold much weight.

---KenRad

 

[rogzog]

Check out this link. It may be what you want or give you some ideas.

http://www.thybar.com/vibrocurb.html

TOK