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Discuss Waste for 100 flats? in the Commercial and Industrial Plumbing Forum area at PlumbersForums.net

macka09

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Hi guys. I’m on a job at the moment where the building has 100 flats over 4 floors. The problem is there’s no mechanical supervisor on site or any drawing in regards to the waste pipe work. One of the issues seems to be, there’s only 5 vents going out to atmosphere. today we’ve been told to run a float in the ceiling void on the top floor to pick up 5 flats on the top floor as well as it serving the 15 flats below. This doesn’t seem right at all. Are there any regs that prevent this or is there any guidance that should be followed? Any advice would be great. I reckon they’re are going to Durgo most of it.
 

ShaunCorbs

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Join them together I’m guessing your using 6” and go through the roof eg split them into 5s
 

macka09

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Join them together I’m guessing your using 6” and go through the roof eg split them into 5s
The only 6” would be on the 4th floor in the ceiling void but back to 4” through the roof. So 4” from ground level then up to 6” on top floor ceiling void but back to 4in through the roof. Each vent would have to serve 20 flats with 2 soils in each. Just seems messed up to me
 

ShaunCorbs

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Seems backwards supposed to start in 6” then reduce :D

My advise follow there instructions but make sure it’s noted down they said to do it like that and get paid
 

macka09

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Seems backwards supposed to start in 6” then reduce :D

My advise follow there instructions but make sure it’s noted down they said to do it like that and get paid
That’s exactly what I’ve said. I’m not clued up on these size jobs. 6” in the ground then 4” for 4 floors then 6” in the ceiling then back to 4” for a vent??? WTF?? Lol absolute Rubbish show. Excuse the pun lol. What job role would be the one that covers this sort of stuff?
 

ShaunCorbs

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Who ever tells you how to do it

Should be mechanical services or m and e designer / engineer
 

scott_d

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Crazy
What about the builders? Ask if they can get you a copy of the drawings. At least you can said you requested if it all goes wrong
 

Chuck

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Have you considered the possibility that the developer is in financial trouble and is cutting costs on 'details' like detailed plans and senior engineers in the hope that the trades will know what to do?

To me, something smells very fishy about the scenario you've painted. Make sure you don't end up as a creditor if/when they go bust.

Also, I wouldn't rely on the "I was only following orders" defence (post 4) without checking with a lawyer firsr. You may have the moral high ground, but it'll still be a system that you installed that is not fit for its intended purposes, which is potentially going to lead to years of hassle.
 

oz-plumber

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How are you employed on the job?
Are you considered the main contractor?

Not sure on your regs over there, but a 4 storey building over her requires a lot more venting requirements.
You need relief vents between each floor on buildings over 3 storeys.

It's a fair bit beyond the domestic plumber to know all the requirements.
Not beyond the capabilities of a domestic plumber to install as long as there are hydraulic plans.

I haven't done anything near 100 flats, mostly in the 20's, but there have always been spec'd plans to follow.

Whatever you do, make sure you're not going to be liable for the work done on the project.
If you're asking the questions on here, it sounds like you're out of your depth and you have concerns.

When things go wrong at a later date, hopefully your not the one someone is going to blame and point the finger at.

A project that size requires fully specified drawings, drawn by a consultant / hydraulic engineer.
 

macka09

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How are you employed on the job?
Are you considered the main contractor?

Not sure on your regs over there, but a 4 storey building over her requires a lot more venting requirements.
You need relief vents between each floor on buildings over 3 storeys.

It's a fair bit beyond the domestic plumber to know all the requirements.
Not beyond the capabilities of a domestic plumber to install as long as there are hydraulic plans.

I haven't done anything near 100 flats, mostly in the 20's, but there have always been spec'd plans to follow.

Whatever you do, make sure you're not going to be liable for the work done on the project.
If you're asking the questions on here, it sounds like you're out of your depth and you have concerns.

When things go wrong at a later date, hopefully your not the one someone is going to blame and point the finger at.

A project that size requires fully specified drawings, drawn by a consultant / hydraulic engineer.
You are right. I am certainly out of my depth I’m there as a subcontracting plumber but there’s no mechanical drawings or specs to follow. I’ve been asked to pressure test this setup to 5bar via the manifolds. I’m not scared to say no and walk from the job. I was originally asked to help on the bathroom installs.
 

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macka09

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Looks a nice set up
It looks smart but no one has the answer for whether we can test from the bottom of the manifolds or whether we have to test each run from above. It’s upunor press on the manifolds but then converts to Hep2o.
 

ShaunCorbs

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Yes as there should be a rubber oring sealing them in as there designed for use with or without meters

Yes prvs need removing before test
 

macka09

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Yes as there should be a rubber oring sealing them in as there designed for use with or without meters

Yes prvs need removing before test
Cheers mate. At least I’ve got some information to answer there demands. They want it tested to 5 bar for 24hrs. This may be my last day I think lol
 
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oz-plumber

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4 story building.
I would be testing to 5 bar at or from the top floor.
If the manifold is on the ground floor, you will need 2 - 3 bar to get the water to the top floor.
Just test the system to 10 bar and be done with it and cover yourself
 

scott_d

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Who’s asked for the test?
Normal there will be test certificates and they should be witnessed by a supervisor.
 

MOSSEP

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Is pressure testing MLCP not similar to plastic pipe, in that the test pressure should be reduced compared to hard pipe like copper etc..
 

ShaunCorbs

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Is pressure testing MLCP not similar to plastic pipe, in that the test pressure should be reduced compared to hard pipe like copper etc..

Most plastic pipes want it testing at 10 bar ?
 

Last Plumber

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I would be wanting the approved plans/tech drawings with sizes on. I wouldn't be making any decisions.
Sure enough you could work it all out yourself but that makes you 'the responsible person' doesn't it?

As you said, beyond the pay grade! Outside the remit!
 

MOSSEP

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Most plastic pipes want it testing at 10 bar ?
Just done my water regs course and it noted that plastic pipe can deform if tested at too high of pressure. 1.5 times max operating pressure is the norm for hard pipe, plastic pipe should be tested at 1.1 times design pressure.
 

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ShaunCorbs

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Just done my water regs course and it noted that plastic pipe can deform if tested at too high of pressure. 1.5 times max operating pressure is the norm for hard pipe, plastic pipe should be tested at 1.1 times design pressure.

Was reading what hep want they want a test pressure of 18 bar

if any of our slimline fittings are included with the system, then an 18 bar test for minimum of 45 minutes should be carried out.(the old grey ones)
 

MOSSEP

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Some conflicting information there then, 18bar sounds pretty excessive though doesn’t it. Just looked up the JG speed fit test method and it states 2bar for 10 mins and 1then bar for 10 mins, maybe it’s this short time period that prevents damage?
 

ShaunCorbs

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It’s weird would stick to 1.5x myself saw on jg website there fittings and pipe are tested to 44 bar (under lab conditions) so can’t be too bad for them
 

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