[optionalstop]

I have a 3 season room in the back of my house that will soon be remodeled including insulated walls and smaller windows to be used as a year round second living room area with wood stove. My problem is high traffic noise on my street I'm trying to reduce. The one wall, which most of the noise seems to infiltrate through will be re-framed and solid with no windows, but I want to install some type of soundproofing material with the insulation. Will simple foam board do the job or should I buy something made for this purpose. Any recommendations would be great. I know removing the windows from the wall and insulating is a good start but I want to do the best I can to reduce the noise while I'm at it.

 

[chandler48]

I recommend Roxul (Rockwool) Safe 'n Sound insulation. It is waterproof, vermin proof, fireproof, and mold proof. In a 2x4 wall, it gives an R15 value, where normal fiberglas only has R13. A little more expensive, but well worth the investment.

 

[Steve in MD]

Rockwool is certainly a great choice. It does well with absorbing sound and is just a better all around material compared to fiberglass.

A key of soundproofing is mass. Sound transmission is greatly reduced as it attempts to travel through heavy layers of building materials. Use 5/8 fire rated drywall. Its heavy and provides the mass needed for your purpose. Even better, use two layers for twice the mass. This is a common approach in soundproofing applications. You should also use putty pads on the backside of electrical boxes.

One last consideration is using genie clips to decouple the drywall from the framing.

 

[optionalstop]

Thanks for the excellent advice, very helpful. What are putty pads?

 

[Steve in MD]

They are a putty, rubber type matt about 8"x8" that you cover the backside of the electrical boxes with. They take into account that even with the best soundproofing materials(ie double 5/8 drywall), you'll have holes in each wall at every outlet that will allow sound to bypass the drywall. The putty pads help reduce this.