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By Johnny808
Hi Plumbing Folks.

An amateur here trying to build a complete bathroom from scratch. I somewhat foolishly bought my bathroom suite from Victorian Plumbing...yes, I've already read the forums about plumbers cursing their 38mm waste pipes!

So, my problem is...I have a 38mm (OD) metal waste pipe!

I want to install a roll top bath and take the metal waste pipe to one side and out through the skirting board to a 40mm solvent weld pipe.

I need a fitting that's compression one side to take the 38mm pipe and 40mm solvent the other. I don't want a compression/push fitting within the wall, if I can help it. If there are any future joint problems I want to be able to access it. eg. the compression fitting outside of the skirting board. I'll happily machine down one of those plastic compression rings to fit under a chrome cover ring, if need be.

I have looked absolutely everywhere and have not found a suitable fitting. I have a lathe and am even considering making something up myself!

Please help with ideas...I'm getting desperate now! I'll even buy you a beer (post lock down!) :)
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firstly hi and welcome.
i wouldnt have anything as you said in the wall that can leak, so firstly extend s/w pipe 3'' outside wall using a coupling. then perhaps a mcalpine flexcon pipe conector would do the job for the solvent side leaving a comp fitting to go on trap you can pack that out with ptfe tape to take out the 2mm on the comp fitting!! ... ain-spigot

any pics of that trap?

also if i remember correctly the solvent weld pipe is also 38mm o/d!
By Johnny808
Thanks for the reply!

I cannot access the outside pipe. Long story, but I had an extension built and the builders boxed in all the exterior soil pipes. They were supposed to leave access points, but they forgot! They have long since left the country, so I'm stuck. I've just rerouted my basin 32mm waste pipe today in the snow, which involved grinding out some of the fibreglassed 18mm OSB just to get to it. The bath waste is lower and completely built into the roof, so that's a no no!

Will put up pics tomorrow, but I'm interested in what you mentioned about the solvent weld ID!

I was messing about tonight and the 38mm chrome metal pipe does indeed fit the solvent pipe with most an almost interference fit. If the worst came to the worst, could I not slide it, say, 6" into the solvent pipe and use a sealant? If so, what would you recommend? I'm thinking something like Furnox X would do the job? Nice and slippy, yet forms a good seal? It's only bath waste water after all and I'd have gravity on my side?! :)
By joni os
Gravity is not on your side . When level of water in bath is higher than connection, water will escape in all possible directions. People discover this when moving into new home, use sink and discover previous owner had disconnected washing machine from sink pipework without properly sealing connection. By all means insert one pipe in the other but seal connection with compression fitting. OD of smaller pipe can be increased by use of bicycle inner tube, doubling if necessary.
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