Contractor Talk - Professional Construction and Remodeling Forum banner

1 - 20 of 46 Posts

·
Banned
Joined
·
902 Posts
Discussion Starter · #1 ·
A guy I know is building a new house, and has plumbed it all, and now, after it is all in, no gypboard yet, he is wondering about how to make the drains quiet.

We toss around some ideas about wrapping the 3" PVC lines with various kinds of stuff, spray foaming them, etc., and then come upon using sand.

So basically, wherever there is a drain stack coming down inside a wall cavity, you use lumber or whatever, so as to make a smaller cavity for the pipe than a full stud bay (if you can) and then fill that cavity with dry sand as you go up with your second side of gyprock.

Chop out a piece of rock up at the top so as to get that sand fill up there into most of the cavity, then patch and mud the hole.

I know, he shoulda used cast iron, but hey, why won't this work?

BTW, we designed the place with 6" wet walls, and he centered those drain stacks. There is a potential for 1" of sand "fill" between the PVC stacks and the inside surface of the gyprock.
 

Attachments

·
Banned
Joined
·
28 Posts
Thanks, "Electrician," for your kind and thoughtful remark!
You're welcome my friend. Remember, there's never a charge, I offer my advice for free! But seriously, if this was such an amazing idea, everyone would be doing it. The weight of the sand will flex the drywall and there's probably a host of other reasons this is not an accepted practice.

;)
 

·
Thom
Joined
·
4,137 Posts
though I'v not tried it, I would think foam would be a better alternative. It would hold the pipe rigid enough that the vibrations should be stopped.
 

·
Banned
Joined
·
902 Posts
Discussion Starter · #7 ·
I don't think it will flex the 5/8 type-X rock that is being used throughout.

If it is done for home theater walls for sound (and it is), then why not this? We thought about some kind of a sock to localize the sand as a "wrap," but that is difficult to pull off. The blocking, so as to house the stacks in tubes about 5.5 x 6 max ought to work just fine, and sealants will be used to keep things tight.

What's an Electrican doing as a GC, anyway?
 

·
Zimmermann
Joined
·
328 Posts
I usually stuff the cavity with batt insulation, attach R channel to the studs horizontally (could use furring strips) and double up the drywall. 1st row hung vertically, acoustic caulk in seams , second layer of drywall hung horizontally, tape and mud.

Anything more than this youll be buying expensive sound isolating products like hushboard or different membranes for professional soundproofing projects....
 

·
I own stock in FotoMat!
Joined
·
12,611 Posts
Two words: cast iron. :whistling
 

·
Registered
Joined
·
2,096 Posts
I think sand is overkill. The frequencies from water are in the high end, and those are the easiest to suppress. Sand in a sound studio works because its mass blocks the low frequencies.

Is there enough room to glue strips of sonopan (http://www.sonopan.com/) to the back of the drywall and sides of studs?
 

·
Registered
Joined
·
3,951 Posts
A builder I used to work with would wrap all his pipes with carpet padding. Although I don't know how bright he was, his guys were wrapping the plumbing vents with padding too.
 

·
Contractor
Joined
·
4,736 Posts
I second, not third, er fourth the notion that sand isn't good. if there are humidity issues, the sand may react poorly. if there are moisture issues, the sheetrock may fail due do the compressive force at the bottom of the stack (of sand). The 'mass' of the sand sounds like a good idea though :)

If you have an inch between the pipe and wall, try spray foam and adhere piece of rigid foam between the pipe and surfaces surrounding.

I was in a doctors office and heard the toilet from above flush through the partition wall...quite annoying. Would it have been a better practice to slightly angle the pipe and design the system so that the water entering above would flow down the pipe instead of falling?
 

·
Registered
Joined
·
377 Posts
if he's paying you to do it, and you'll make money doing it, and if they're a good customer then DO IT. let them know there is no guarantee of it being effective. Personally, I think you're better off
1.bracing the pipe,
2. wrapping the pipe with therma fiber insulation using duct tape.
3. use 5/8" sound board over that area instead of regular. (while you are rocking as usual)
draining water is not under pressure so it will not be too noisy.
 

·
Registered
Joined
·
377 Posts
I second, not third, er fourth the notion that sand isn't good. if there are humidity issues, the sand may react poorly. if there are moisture issues, the sheetrock may fail due do the compressive force at the bottom of the stack (of sand). The 'mass' of the sand sounds like a good idea though :)

If you have an inch between the pipe and wall, try spray foam and adhere piece of rigid foam between the pipe and surfaces surrounding.

I was in a doctors office and heard the toilet from above flush through the partition wall...quite annoying. Would it have been a better practice to slightly angle the pipe and design the system so that the water entering above would flow down the pipe instead of falling?
did u hear the water rushing, or the actual flush? Seems standard builder grade homes are put together withiut much thought to these things. Bathroom and bedroom walls should be double layers (both sides) of 5/8" MINIMUM, along with therma fiber and solid doors. It doesn't cost much more to do that, and it goes a long way.
 

·
Contractor
Joined
·
4,736 Posts
did u hear the water rushing, or the actual flush? Seems standard builder grade homes are put together withiut much thought to these things. Bathroom and bedroom walls should be double layers (both sides) of 5/8" MINIMUM, along with therma fiber and solid doors. It doesn't cost much more to do that, and it goes a long way.
this was a doctors office-commercial frame two story construction and the sound was water flowing down the pipe-not sure if it was a flush or a drain.
 
1 - 20 of 46 Posts
Top