Some plumbing help *pics*

[neds]

Hi there,

New here and this looks like a great forum for hints and tips, I was wondering if you could advise on my problem. Probably a simple job for you guys!

Planning to fix the plumbing outside the house, I think the cold weather has blown the fixings.

Anyway here is the picture to illustrate:

Now whoever fitted it originally used some 36mm waste pipe for the sink drain and 40mm pipe for the bath drainage. The 36mm doesn't seem to be a standard fitting and I know it definitely is that size as I measured it with a vernier caliper inside and outside so don't think it shrunk? I thought they only came in 32 or 40mm fitting for soil/waste pipes?

The drainage pipe coming out the bottom of the sink is also 36mm and it seems like a whole load of work trying to fit 40mm pipe (drilling bigger whole etc...)

Also ignore that electrical wire running along the bottom, its not used!

I bought some 32mm piping a 32mm pushfit L bend and 32mm Strap on boss, I was wandering if I should replace the old 36mm piping from the sink drain and use 32mm piping instead, this will mean i will need to replace the sink trap too as that has a pushfit connection for a 36mm pipe.

Also what is the best kind of sealant/solvent to use to attach the strap-on boss?

Any help most appreciated.

Cheers

 

[hi-spec plumbing heating]

use solvent weld all the way not pushfit.
32mm is standard size for a basin.
waste is measured internal diameter not outer.
and use grey as that is uv protected

 

[ChrisR]

To reiterate, really, pushfit is (mostly) very bendy stuff which sags horribly. It's also (usually) a different size, and won't solvent weld.
To reuse the waste boss on the soil pipe, which looks like it's an "Expansion coupling", ie not technically push-fit(!) you may have to replace or clean and grease the rubber ring in there.

Suggest you use a slower bend than the sharp knuckle type currently used on the basin. Or a T with an access for rodding

NB sinks are in Kitchens, 40mm wastes.

 

[neds]

Cheers guys will look into them suggestions.

 

[chrishutt]

Neds, you're confusing nominal sizes with actual OD sizes. for example 32mm nominal pipe has an OD of around 36mm, 40mm nominal has an OD of around 43mm. It's slightly more complicated by the fact that there are two slightly different sizes in each nominal size (god knows why!), typically push-fit pipe being slightly smaller than solvent weld, but not always (that would be too simple).

Like many before you, you're also confusing sinks (in kitchens - 40mm) with wash basins (in bathrooms - 32mm).

Why do you want to change the existing pipework anyway?