Waste going up-hill

[Carlnorwich]

Untitled

• Carlnorwich
• 2 Jan 2009
• 1

I recently had a plumber install a new shower tray and run/connect a new waste to the existing svp in my upstairs bathroom.

The plumber drilled holes through the existing joists for the waste pipe. The overall fall of the waste is very slight and on the bend it actually falls the wrong way. I could slide a small block of wood under the corner that would lift it up slightly so the waste would fall all the way (very slightly).

I'm not really happy to do this as I paid good money for the CORGI registered plumber to do the job corectly. See my suggestion drawing; I would guess that the waste should go directly to the joist and then use some sort of flexible pipe to get it round the corner?

The plumber was a good bloke and I'm sure he will come round and sort the problem, however, I would like to make sure he does it right this time.

Could you please advise how the problem should be sorted, and I'll make sure he does it properly.

Many thanks in advance.

 

[seco services]

don't know why he never used a 45 bend to start with.

 

[bengasman]

Unless your joists are extremely over dimensioned, routing a waste through holes in joists is wrong, dangerous, illegal and stupid.
It needs a 4 degree fall and if it is significantly less, like in your case, it will be problem prone and most likely suffer from blockages.

I am afraid that in most cases the only way to do this properly is to remove the waste pipe, repair the joists, and find another way to dispose of the water.

 

[petetheleak]

Corgi registered doesnt mean he is able to do bread and butter plumbing tasks ,

 

[bengasman]

Corgi registered doesnt mean he is able to do bread and butter plumbing tasks ,

Indeed. It does not mean he is not a cowboy either.

 

[petetheleak]

"Cowboy" your words not mine .

 

[seco services]

Unless your joists are extremely over dimensioned, routing a waste through holes in joists is wrong, dangerous, illegal and stupid.

not illegal at all you can fit a 40mm waste through a 8" joist and be in the regs.

 

[ctp]

was it not possible to put the shower nearer the soil pipe(windows poss)?

 

[Carlnorwich]

was it not possible to put the shower nearer the soil pipe(windows poss)?

Unfortunately this is the only position the shower could be installed.

I agree using a CORGI registered plumber doesn't mean he's going to be expert in running waste pipes, but the registration tells me he's probably not a 'fly-by-night'.

I had 3 different plumbers look at the job (2 of them gave me high prices), all 3 said thay would drill through the joists so I guess it's okay to do that.

Still not sure how he should rectify the problem?

 

[seco services]

how deep are your joists 6", 8" ?

 

[blondini]

I think your own suggestion is probably the best solution, but using 45 degree bend rather than a flexible coupling.

An alternative way would have been to run waste straight from left to right in your diagram then a 90 bend to go 'upwards' <auto pun off> into the soil. Limits on where joist can be drilled may have eliminated this route

 

[Fluffster]

Have you actually tested the waste to see if the trap overflows on full cold setting?

You say you paid good money for a Corgi registered plumber I thought you chose him because he was the cheapest?

Chock the waste pipe up where you mentioned and carry out a full flow test.

Pete

 

[gas4you]

His surname didn't begin with H did it

And did he have an accent from oop north

 

[bengasman]

Unless your joists are extremely over dimensioned, routing a waste through holes in joists is wrong, dangerous, illegal and stupid.

not illegal at all you can fit a 40mm waste through a 8" joist and be in the regs.

Not in itself if the joists are indeed 8". Problem is that when you have 8" joists, you are normally looking at 4 or 5 metre width, and I don't see a lot of bathrooms that big. That also means you are either running a level waste pipe, or you will be drilling well out of the middle. neither is good.

 

[Carlnorwich]

I will do a full cold test to see if it backs out of the waste - thanks for the advise.

I think I will get him back and ask him how he is going to sort it and see what he comes up with.

The joists are 8" by the way.

Thanks to everyone for offering your advice.