Keeping **it down to a dull roar?

[ToughButterCup]

Our house design has an internal soil stack. So we need to think about noise. Have a look at this diagram.

 

The brilliant thing about our design is that the wetroom is built onto the front wall of the house - so (below the level of the flat roof shown)  there are insulated blocks inside the heated envelope.

 

That means we can cut out the insulation and use the space created for other things - like hide a soil stack. And deaden the noise.

 

But I only get one stab at this little problem. I need to get it right. So I'd like to 

• fit acoustic piping (like this) or (maybe this) 
• additionally encapsulate the acoustic pipe in  sound-deadened (proofed is impossible I think) trunking.
• maybe double the amount of plasterboard on the ceiling under the upstairs bathroom
• meet and exceed the proofing levels required in Part E 

 

Have you had to deal with a similar problem? How did you work it out? Is the general approach outlined above sensible? Do you have any comments.

 

I'm feeling a bit 'exposed' on this one.....

[ProDave]

We have one soil stack for almost everything.  Upstairs it serves (or will when finished) 2 toilets, and showers etc.

 

It drops down vertically in the corner of the utility room and the downstairs loo joins it just below the floor.  "everything" lands at the bottom straight onto a rest bend to take it out through the wall underground into an inspection chamber.

 

I can say ours is performing at the "barely perceptible rumble" end of the spectrum.

 

Why do you branch it and step it out into the room at the bottom?  That is where you will get noise if any.  Can that not stay in the wall until under the wet room?

 

Can you get the 45 degree equivalent of a rest bend? i.e. a much longer, gentler radius 45 degree bend?

[Jeremy Harris]

Our's much like @ProDave,s, a single vertical soil pipe that runs behind my study wall and drops into a rest bend under the slab.  It's inaudible.  All I did with ours was box it in with 12mm OSB where it comes down partly in the downstairs WC, with the box being filled with packed in rockwool leftovers from the wall and ceiling acoustic insulation.  Plasterboard was bonded on to the OSB with low expansion foam.  At a guess there's probably only about 50mm of insulation space around the pipe, maybe less, but that seems enough to silence it. 

[Construction Channel]

Pure speculation here. But underneath most metal sinks there is a pad stuck to it. 

I was told this is to deaden the sound if the tap drips. 

Would sticking a "pad" on the underside of the bends help at all? 

[Onoff]

I recall Nick saying that gun foaming in my horizontal soil pipe in the wall wouldn't do much to suppress noise and that Rockwool would be better. 

 

However the only sound heard is from the Geberit in wall cistern (might as well be silent) and the rimless Bernstein pan as it does it's thing and that is really quiet too. Filling noise is imperceptible pretty much.

 

I hear more "pipe" noise oddly downstairs when the upstair en suite flushes and everything passes the end of the horizontal pipes at the branch a couple of metres from the downstairs wall hung. I guess it echos?

 

 

[Ferdinand]

That’s a remarkable run, and reminds me of the Astroglide at Rhyl Ocean Beach from some years ago.

 

Can’t locate a pic, but do you have to have some sort of way of making sure that the radii are tightening (so to speak), or it might go Wheee! Wheee! Wheee! all the way down.

 

I think that unless you have overhangs flowing liquids will adhere to the edges, and solids slide.

 

Will look for pic of the astroglide.

 

/tasteless

 

I get pipe noise, but I think it s inadequate ceiling insulation and soil pipes that run through the toblerone spaces around my rooms in the roof.

 

Ferdinand

 

 

 

Edited August 28, 2019 by Ferdinand