Weeping gutter pipe

[Stringman_uk]

Hi All
I am having problems with my downpipe leaking.
I suspect that its because I am connecting things in the wrong way but Thought I would ask.

Very old house and the guttering downpipe went straight into a water butt and the overflow went into the drain,
The waste from the kitchen came from a seperate pipe to the same drain. ( I know that shouldnt be the case but thats the way the system has to be/ has been for years)
So in an attempt to neaten it up after having decking installed I have removed the water butt. Down pipe comes down the side of the house and goes through a 92 deg bend. Just before the drain (where the kitchen waste comes out) I have installed a pipe branch ( https://www.screwfix.com/p/floplast...VUO7tCh0YjAvpEAQYASABEgJidvD_BwE&gclsrc=aw.ds )
The 40mm waste slots into the angled branch via a reducer.

The pipes have been cut with a fine toothed mitre saw so are straight and clean and the joins seem to sit flush.
But the join on the left of the branch is leaking.

To be fair I havent cemented them , but didnt want to do that to find there is some inherent problem with what I am doing.

Any thoughts on what I am doing wrong and how to solve it?

Many thanks in advance

 

[Hugh Jaleak]

You have 'Combined' drainage, where rainwater and foul go into the same sewer. Common in older properties, the Victorian principle, so the drainage system gets a good flush through every time it rains heavily. (Only problem is now, it overloads the system, Combined Storm Overflows are used to relieve the excess water from the system and people start complaining about sewage spills....)

Nothing wrong with what you've done, my only advice would be to run the pipes down to terminate nearer the gully gird if there's room, as is, splashback, (especially from the sink) will foul the surrounding area, may stink in hot weather, and will make the decking rot quicker. Once happy with the setup, you may need to glue the joints together to prevent any leaks.

 

[Stringman_uk]

Thanks Hugh
the drainage system copes ok with the flow, my only problem is with the leak

 

[Madrab]

The key is in the name, that is rainwater downpipe, it's designed to be used vertically, it isn't really designed to be used on the horizontal with very little fall.

The way that system works is when vertical the male goes into the female socket there's no path for the water to track back and it's just push fit, once it's goes vertical then the water can capillary back up and out through the joint unless you use correct adhesives specifially for uPVC and roughen up the joint.

A lot of normal cements used for ABS also say they can be used for PVC but they're not really designed for rigid uPVC, get one that is.

 

[Stringman_uk]

Thanks Hugh
the drainage system copes ok with the flow, my only problem is with the leak

 

[Stringman_uk]

Madrab
Thanks for that. This is the cement I used. I kind of presumed that it was the correct one as it was by the same company?
I shall look at what you suggested!

 

[Madrab]

Nope, that cement is better on ABS and normal PVC, uPVC is a bit of a different beast and needs a better suited cement adhesive. It is a bit more expensive so only get the amount you need.

Only reason I found out the difference was when using uPVC rigid pipe where a chemical resistant pipe was needed. Normal solvent cement was no good as it leaked under testing.

 

[Stringman_uk]

Madrab
Thanks so much, maybe that explains the leaks!!!
Problem is if its wrong in means a whole set of pipes and bends - hey ho

Does this look ok?

 

[Madrab]

Nope

Thanks so much, maybe that explains the leaks!!!
Problem is if its wrong in means a whole set of pipes and bends - hey ho
Does this look ok?

Nope, unfortunately not, again that's for normal PVC/ABS, not rigid uPVC, that's the same solvent cement as the Floplast. It's just toolstation's brand.

You need cement specifically for rigid PVC (uPVC), chances are you won't get it at one of the sheds, you'll probably need to order it.

 

[Stringman_uk]

Thanks for that, you are correct I have had to order it in.
But hopefully saves me waste more on fittings!

 

[Madrab]

Should do, just prep the pipe/fittings well, bit of 80 grit and roughen/clean them up and coat the pipe well, not the fitting, wait 30secs then fit and twist a few times then wipe away any excess.

When you get it, compare with the Floplast stuff, you'll notice the difference. You can use that stuff on ABS as well as PVC/uPVC/mPVC/etc, it doesn't work the other way though.