Slight Drip from Soil Pipe at base of Soil Stack

[TheRealRobG]

Hi there.

I'm replacing an existing toilet in our downstairs cloakroom. The soil connector on the base of the new toilet is quite a bit higher than the old, so I needed to replace the soil pipework. Also wanted to make a clean start and not use filthy 20 year old pipes.

Put together what I think is a pretty reasonable set of pipes from an elbow, 2 x 135 deg connectors (to make it adjustable) and a straight section as shown below:

The long straight doesn't go into the soil stack port perfectly straight, but it's not far off - perhaps a couple of degrees out. It goes in straighter than the last one though - which was just a long straight length of pipe with an elbow on the end.

The problem is that there's a very slight drip coming from the base of the soil stack connector after the upstairs toilet flushes. A few very slow drips, then it seems to stop:

Some damp on the plasterboard next to the area makes me think the old pipe was doing this too.

I don't realistically have the option to adjust the soil stack, but I was wondering whether I could make the joint any more watertight, perhaps by withdrawing the new waste pipe out part-way from the stack port and smearing it with something more than the lubricant gel I used to fit it?

I have some 'Water Hawk' jointing compound, some 'Boss Supergreen' pipe jointing compound and dome 'Plumbers Mait'.

Or could clean up the connection and smear a ring of mastic around the joint to try and stop the leak. I see this as a bit of a bodge, but if it'll do the job...

Any advice gratefully received.

Many thanks.

 

[wheeto]

That bend to the back of the toilet ooks nice & neat 🙂

Probably just a bit of grit / dirt on the seal so yes you can try & adjust it and hope that the debris moves or you will have to take the joint apart, inspect the seal, apply more silicone and then re-fit. No magid I'm afraid...

 

[justalex81]

rubber is probably slightly brittle so pull it out and replace it. as above remember to apply silicone grease to the rubber and pipe when pushing together. make sure you chamfer the end of the pipe aswell.

 

[TheRealRobG]

That bend to the back of the toilet ooks nice & neat 🙂

Probably just a bit of grit / dirt on the seal so yes you can try & adjust it and hope that the debris moves or you will have to take the joint apart, inspect the seal, apply more silicone and then re-fit. No magid I'm afraid...

Thanks! That sounds like a good plan. I didn't know the seals could be replaced. Are they all a standard size, or are older ones likely to be different? This one dates from circa 1991.

 

[sheff paul]

Looks like from the pic it isnt falling properly and trapping water and leaking,this might be a major bummer if it keeps getting blocked,i would bite the bullet ,re fit it use some proper silicone lube on the o rings,give it a good test,and you will sleep so much better at nite

 

[AWheating]

get some wire wool on those copper pipes 🙂

 

[Bernie2]

Hmm!

Dirt on seal, worn seal or displaced seal when pushing in new pipe. Plenty of silicon grease. Do not use any oil based jointing, washing up liquid or swarfega to help slide pipes together. It rots the seals or they go hard and stop expansion.
Drift out pipe, use solvent weld cleaner and solvent cement weld the new pipe into the socket if the plastics are compatable and expansion is under control

 

[TheRealRobG]

Thanks for all the suggestions!

 

[Howsie]

The angle of the soil pipe is a concern, you need a continuous fall.

 

[wheeto]

The angle of the soil pipe is a concern, you need a continuous fall.

The fall looks OK to me. At the risk of pointing out the bleeding obvious, you do know that the second picture (not the inset) is taken from above?

 

[Howsie]

The fall looks OK to me. At the risk of pointing out the bleeding obvious, you do know that the second picture (not the inset) is taken from above?

LOL - that'll teach me for looking at the forum at 3am when I can't sleep. I'll get my coat. 🙂

 

[sheff paul]

The fall looks OK to me. At the risk of pointing out the bleeding obvious, you do know that the second picture (not the inset) is taken from above?[/QUOTE



Thats my credibility ''down the drain'' so to speak