Plumber says he can't fit our new toilet cos the building's soil pipe is narrower than the toilet's-This true?

Question

He says that there is a high risk of the toilet blocking. If this is true (probably is) can we do anything to mitigate the problem?

Here's some more details: it's a 1965 apartment building in France. I don't know the diameter of the soil pipe for sure but I think it's about 85mm? We want to fit a suspended toilet that has a (standard?) diameter waste exit. According to the plumber there's only one toilet on the market that has the narrow exit. And of course it's not a suspended one. I'd like to go ahead with the suspended toilet plan - but not if it's going to block!

Answer 1

I'm a GC, not a plumber in the strict sense; but I am confused a bit. I want desperately to assume this "PLUMBER" assumes other issues, beyond fitting reducer/enlarger/transitional fittings?

Certainly without knowing at all the situation; the new toilet; the size of the existing waste plumbing; or the need to replace the toilet; supposition might be all you get here?

Did the blockage problem exist with the old fixture? What ID does the waste plumbing have currently? What's the GPM flow rate of the new fixture? Etc. Etc. Etc.

Steven Wolf

Answer 2

See if that plumber or another one could find a toilet that matches. I've heard of this problem before. Especially when the apartment unit is one on the lower levels. To much sewage going down a tiny pipe all at one time. At work we had to find, just about the exact toilet that cracked. In-order to replace it. If it's an apartment, the manager should foot the bill. If it's a condo, the association should help. If your a home owner you may have to get some of the pipes switched.


Too bad they can't install back-flow preventers on sewage lines.

Answer 3

I find it hard to believe that the only viable solution to your problem is a specific brand of toilet. 85 mm is larger than our standard 3" soil pipe and most closet bends in the US are installed in 3" pipe. Replacing the toilet may require the installation of a new closet flange, one that would both adapt to the existing pipe and to the footprint of the new toilet. The toilet your plumber wants to install may not require the aditional work of adapting the flange. It's very hard to say, though, without seeing it.

As for the pipe size, 85 mm (>3") should only be an issue if you have multiple bathrooms or fixtures running through that pipe (i.e. too many fixture units).

Answer 4

If I'm not mistaken, there are adapters such as a 4 inch to a 3 inch....etc....
The main problem is that you'll be initially able to flush a certain amount of "stuff" but once it gets to the smaller portion of the pipe, it creates a bottle neck so everything will slow down or even come back up.....
Cant he find a toilet to accept the existing size of the pipe?

Answer 5

Your plumber is talking rubbish, in the UK there is a device called a "Multi Quick" which reduces the size of your toilet outlet into the soil pipe.