New toilet 82mm soil

Joined
19 May 2019
Messages
5
Reaction score
0
Country
United Kingdom
Hi,

We've got an old larder space that we're thinking of converting to a downstairs toilet and sink. Trouble is it's in the middle of the house with no soil pipe nearby. We were initially thinking of putting in a Saniflo (or a Wasterflo WC2 rather). But anyone you talk to seems to say to avoid macerators. I'd much rather have a normal toilet if possible.

There's a possible route through under the kitchen units as there's a 140mm high gap underneath them.

Initially it'd be a 1.5 meter unrestricted run from the toilet into a 90 bend then the only way is through under the kitchen units for another horizontal run of 4.5 meters all the way out of the house. After that another 3 meter run to a sewer drain cover in the back garden.

The main problem is the run under the kitchen units as in theory with 110mm pipe I'd only have 30mm height difference under the kitchen units. It would mean a drop of 30mm in 4.5 meters which is less than 1 in 100. I would need a minimum of 45mm to achieve 1 in 100.

If I were to use 82mm pipe it would give me 58mm to play with and I'd be able to get a much better drop. Perhaps 1 in 75 which would be ideal.

What would be better 110mm pipe with less drop or 82mm pipe with a better drop? According to the regs 82mm is ok to use as long as it has a single toilet on it and the toilet outlet is less than 80mm? I've looked at toilets online and there's no mention of the outlet size in the specs. Are these toilets common? Any suggestions?

Also the other things is 82mm pipe seems to be rare and expensive... also the fittings seems hard to get hold of. Maybe I'm looking in the wrong place but £30 for 3 meters of straight pipe and over £15 per fitting seems expensive.

What do you guys think? Any suggestions are much appreciated.
 
I’d use the 110mm and have an accession the outside, just in case. At least if it’s under your unit it will be easy to get your fall perfect.
 
I’d use the 110mm and have an accession the outside, just in case. At least if it’s under your unit it will be easy to get your fall perfect.

Yes definitely putting an access elbow as soon as it comes out. Would the drop prove an issue seeing as it would be less than 10mm per metre though? I'm not worried about the water as it'll flow downhill no matter how small the drop but would it prove a problem if the water is only flowing slowly and perhaps not taking the solids with it. :sick: Although I think it'd probably be ok.
 
I’m sure it would be fine. You next flush would take any leftovers from the previous one.
 
Many thanks. I’ll go with the 110mm. I may be able to get a better drop anyway and try remove the bottom of the last kitchen unit and put it back higher.
 
Not being funny but I'd restrict that new WC to No. 1s only. Still better than a saniflow.
 
Back
Top