Connect 40mm solder to existing 32mm pushfit waster

[danped]

Hi,

I have an existing 32mm pushfit waste and I need to connect to that with 40mm solder weld. The pipework is going to be under a shower tray so not accesible in the future without a big effort. I'm keen to get a good joint that will last a long time. I know solvent weld is best but reusing the existing pipework is very attractive.

Would a 40mm to 32mm compression reducer work, and if so am I taking a chance that I'll be ripping up the floor in a few years?

Thanks,
Dan

 

[longdogs]

Personally, I would consider changing the whole waste to 40mm solvent weld although the trap will still be compression.

 

[Burnerman]

It will work but please be aware, push fit stuff is not UV stabilised so if used outside it doesn't last for ever! I'm having to replace stuff thats only 6 years old, much to my surprise.
John

 

[Madrab]

The trouble I find with push fit is the seals shrink as they age and lose their seal over a long time. Therefore it's hard to guarantee push fit will never leak in the future as it goes through hot and cold cycles (expansion/contraction). Needs to be well supported (clipped) too.
When it comes to compression fittings and traps then I find good quality makes a whole lot of difference.
McAlpine is as good as it gets in my book and if fitted correctly with a little smear of silicone grease coating the whole seal (avoids it hardening and shrinking in the future) seals well and lasts as long as needed. Just run the rest of the waste in solvent weld if it's to be underfloor for a long time.

I understand that cost wise, using the current is preferred and will last, it's how long I guess given it's already aged.

 

[Hugh Jaleak]

I would also be concerned about reducing from 40 to 32mm mid run, you're inviting trouble, especially depending on what the waste is taking the water from. Soap scum, hair etc can soon build up and then the problems start.....

 

[longdogs]

If you are going for a powerful shower then all 40mm would be better.

 

[danped]

Thanks! I think I'll switch to solvent weld all the way.