Hush pipe!

Here's a problem the professionals probably get asked all to often.

When installing a 3" PVC inside of a 2x4 stud wall, how do you insulate it? There is no room left.

Thanks,

Pete

P.S. short of doing the wall in a 2x6 or firing it out...

Cast iron, the quiet pipe.

Sure, only then, when you conside the hub you're looking at even bigger than 3 1/2" -- so you're back to 2x6, and then you could just run PVC with insulation with even less noise, half the work, and easier to work with.

If it's an outside wall... nowadays 2x6's are fairly standard. Inside walls, the only good the insulations is really going to contribute is a little noise reduction. If I had to do it... I'd just stuff it the best that I could and go on to the next project. If nothing else, split it and stuff around pipe. cover with plastic to help hold in place while you put up drywall... will also help as a moisture/wind barrier.