35mm copper waste pipes - bath & sink

[Emilian]

Hi

I am in the process of refitting my bathroom.

Both sink and bath have 35mm (external measurement) copper waste pipes. The wastes are independent of each other and separately boss into the 110mm soil stack in the garage below the bathroom.

I am trying to avoid removing the copper pipe entirely as I am concerned about affecting the integrity of the boss connections with the soil pipe. I really wouldn't want to have to cut out a section of the soil pipe in the garage as access is very tight (it is recessed into brickwork so closed in on 3 sides).

I would ideally like to connect plastic pipe to the 35mm copper (closer to bath/basin ends) - is there any form of adapter or can plastic compression fittings be used (if so which ones) ?

Is it best to hook up 40mm or 32mm waste to the bath that then couples with the existing 35mm copper waste ?

Thanks for any advice you can offer

Emilian

 

[petertheplumber12]

The bath waste should be 40mm or 1 3/4 and any smaller is wrong, you should get rid of the copper however difficult and never reduce the size. Waste pipes get blocked easy enough with soap without making it easier. There is not a simple solution in my opinion.

 

[Emilian]

Thanks Peter.

I had read that you shouldnt reduce waste pipe sizes. Whilst I appreciate 40mm is what a bath waste should be clearly 35mm has been ok for 40-50 years.

Is there a mechanism for connecting 40 plastic to 35 copper - surely this way round isnt further restricting/reducing the pipe.

Indeed if it was 32 plastic from bath to 35mm copper this seems only a small reduction.

I'm generally concerned to do things properly but soil stack is in a pig of a position.

I'll try to post some pics tomorrow to show the boss joins /stack etc.

Thanks again

 

[CBF]

The bath waste should be 40mm or 1 3/4 and any smaller is wrong

where do you buy 1 3/4" waste pipe from ?

 

[petertheplumber12]

1.5" 40 mm Solvent weld is best from almost any hardware outlet, b&q, wicks,screwfix, ironmongers shops etc

 

[Charnwood]

1.5 = 11/2
13/4 = 1.75

In the good old days you could get 11/4" bath and sink wastes.

If the OPs bath is draining OK and can cope with draining with both taps on without risk of overflowing (plug out) then it aint broke, so don't fix it.

 

[Nige F]

Hi

I am in the process of refitting my bathroom.

Both sink and bath have 35mm (external measurement) copper waste pipes. The wastes are independent of each other and separately boss into the 110mm soil stack in the garage below the bathroom.

Emilian

keep the 2 wastes @ the bosses - leave 2 stubs - as you thought - then use McAlpine couplings to adapt to plastic - google it , you`ll see they`re sold @ loads of merchants .

 

[Nige F]

Hi



the 110mm soil stack in the garage below the bathroom.

Emilian

I presume that`s a cast iron one -

 

[doitall]

Loads of plastic x copper compression waste fittings available. It will be 11/4" or 11/2" not metric

The copper is worth a lot of brass for scrap, but the more you re-use the better.

 

[Emilian]

Hi

Thanks for all the advice so far.

To clarify a few matters:

- The copper wastes boss into a 110mm plastic soil stack. The boss seems to possibly be some sort of compression joint but TBH im not sure. The tightening nuts/ring on the lower boss has split. Neither boss leaks. See photo below:

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• Emilian
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• Emilian
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As can be seen from the above pictures the soil stack is recessed into the wall so enclosed on 3 sides - there is probably only a couple of cenimetres either side. Following shows copper waste pipes from bath / sink in garage:

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• Emilian
• 16 Jan 2013
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• Emilian
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Then we have the sink:

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• Emilian
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and bath connections:

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• Emilian
• 16 Jan 2013
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• Emilian
• 16 Jan 2013
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I remeasured the copper with calipers again tonight and it is definately 34-35mm - this puts it at approx 1 3/8" it is slap bang between 1 1/4 and 1 1/2.

Bath drains fine - on full chat hot and cold it filled the bottom inch or so of the bath then steadied and drained happily with a very very slight rise (1cm max) over 5 mins before I lost pressure having drained the cold water tank in the loft ! So I dont think overflowing will be an issue. Infact the weak link for overflow is indeed the overflow which is the smallest guage of 26mm (external measurement).

So having seen it in its full glorey what options do I have. I am most keen to avoid having to cut and put new sections in soil stack due to the restricted access and knowing that couplings are hard work even with lube. There doesnt appear to be much room for manipulating a slip coupling up and down the soil stack - I suppose it could be gently persuaded with a hammer and something to tap from either side.

Re: macalpine couplings - I did google and looked on there site but wasnt entirely clear what would do the trick - can anyone link to something ?

It also looks like the copper wastes are only supported by their joints to the bath/sink and then the soil stack - unless there is something i couldnt spot hidden at the moment between the joists.

To be clear I am looking at how I can replace and plumb in a new bath and sink.

Thanks agian for your time in repponding

Emilian

 

[doitall]

I would keep as much of the copper as you can because of the supports.

The MacAlpine straight socket is S28M.

The copper is imperial so measured ID and not OD

 

[Emilian]

Bump

Thanks again