Author Topic: Soundproofing ductwork  (Read 5061 times)


  • Guest
Soundproofing ductwork
« on: April 05, 2002, 12:49:15 PM »
I recently put a basement apartment in our house.  The ceiling was insulated and has 5/8" drywall.  Even after that the sound still seems to get through.  I think the majority of the sound is coming from the ducts.  Is there a way to kill this sound (Foam insert for the duct?).  The noise we hear is talking and tv.


  • Guest
Re: Soundproofing ductwork
« Reply #1 on: April 05, 2002, 11:46:10 PM »
If you believe that the ducting is carrying the airborne sound down through to the basement apartment, you will need to open up the ceiling and wrap the ducting with SSP closed cell foam ( the thicker the better). This material can also be installed to the inside if the duct using contact cement, as it is impervious to water and other liquids such as condensation. You might consider installing SSP flooring to the drywall or the joists prior to rebuilding the ceiling. The flooring would give you and STC of 26 and with the existing drywall you would have soundproofed that ceiling to around a 46 STC rating.
This should quiet the duct transmitted noises. There are many other soundproofing solutions to this problem, but this might just be the simplest.
Bob O.