Help wanted with kitchen drain waste pipe blocked

[wig]

I have a blocked 43mm white PVC waste pipe. I have cleaned the traps underneath the sinks.

The internal pipe is about 6m long and has 2 sinks inline along its length.

Where it goes out the wall it is all glued together and has a length of about 2m where it then goes into the soil stack. On this external leg the pipe has a slight sag in it which looks like it could be where gunk has built up inside and where the blockage is.

I'm thinking I might have to cut it all apart and rebuild the external leg. The problem with this will be the 90° elbow where it comes out the wall is really tight to the wall so I will probably have to end up replacing a part of the pipe to go through the wall.

has anyone tried removing the 90* elbow at the wall with heat to melt the glue or soften the plastic? As youtube videos show.

I am concerned if I was to try spirit of salts first that it would eat away the glue on the joints? What do you think of this risk?

I had an idea that is on the straight run with the sag outside.. on the 90° elbow before that run, if there was a cap built into the 90° elbow all you would have to do is remove the cap and push a rod down the pipe to clean all the gunk straight into the soil stack. and if it had a screw cap you could do this in 5 mins as maintenance once a year.

Do they manufacture special model of 90° elbows with access caps for this purpose? If not, I could fit a T-junction and put a blanking cap on one end of the 'T' do PVC waste pipe have screw on blanking caps?


https://www.wickes.co.uk/McAlpine-T23U-Blanking-Cap---40mm/p/118623#


Stuff I have now is glued - white - 43mm polypipe.

Where it goes in to the soil stack with a 43mm black plastic joint wrapped around the stack.
How do I remove the white pipe from the black soil stack? I will try undoing the strap. Will that be glued as well?

Given that it is all 43mm will I have to replace the whole lot? right up to the sinks including the traps, assuming acid or a flexible 7m rod doesn't work? Because 43mm is not available anymore.

Thanks

 

[Celeronmanuk]

Never tried removing solvent weld. But presume you've tried something like caustic soda to clear the blockage?

 

[just pumps]

Never tried removing solvent weld. But presume you've tried something like caustic soda to clear the blockage?

No, No and NO!
You can cut and use a straight connector to re join solvent weld pipe. Start by cutting out the section with the sag.

 

[HERTS P&D]

Have you got a wet vac?

Andy

 

[just pumps]

Have you got a wet vac?

Andy

Fair point however would you leave a pipe with a sag Andy?

 

[HERTS P&D]

No.

Andy

 

[Harry Bloomfield]

You can trace which sections of pipes are blocked, by tapping it and listening the the hollow sound or not. If a pipe is movable slightly, you can also tell by the weight of it whether or not it has contents inside.

 

[just pumps]

You can trace which sections of pipes are blocked, by tapping it and listening the the hollow sound or not. If a pipe is movable slightly, you can also tell by the weight of it whether or not it has contents inside.

If it is empty but this is full of water.

 

[Hugh Jaleak]

Firstly, do NOT use Caustic Soda, it's evil stuff, may not shift your blockage, but may well remove your skin/tissue and anything else it gets splashed on. It needs banning from public sale.

Secondly, I've never yet come across a way of getting solvent welded joints apart without destroying the pipework, forget that idea.

The best method of removing a blockage is by mechanical means. Either a Plumbers snake down the pipe, wet vac to suck it out, or worst case scenario, cut a section of pipe out, and replace.

Strap is probably glued to the stack, this makes the joint usually. Waste pipe is then connected by a boss adaptor, some are simply a rubber reducer that pushes home, others are a plastic fitting that glues into the boss, with the waste pushing into that, and a rubber O ring making the seal. If you're really unlucky, and it's a Terrain solvent welded stack, then the waste could be glued directly in... If unsure, can you stick a photo up, we'll soon tell you whats what.

Lastly, if replacing the pipework, then 43mm is the '40 mm' waste pipe and fittings. 43mm refers to the external diameter, 40mm is the internal bore. Tip, use a Tee instead of a bend and fit an Access cap in the unused socket. You've linked to a blanking cap that fits on the end of a piece of pipe, a fitted cap is neater. FloPlast WS31W Solvent Weld Waste Access Cap - White 40mm | Wickes.co.uk

 

[Harry Bloomfield]

If it is empty but this is full of water.

Yes, but you can trace were the 'full of water' comes to an end and know that is where your blockage must be, before that point.

 

[wig]

Thanks guys,

and Thanks Hugh,

I'll see what I can do about a photo

siphoned most of the water out already.

and I'll measure the pipe. I got a spare bit of pipe it says 40mm / 43mm on the pipe.

 

[Celeronmanuk]

No, No and NO!.

eh?

 

[Celeronmanuk]

Firstly, do NOT use Caustic Soda, it's evil stuff, may not shift your blockage, but may well remove your skin/tissue and anything else it gets splashed on.

Well yeah, that's the whole idea, dissolves organic matter like hair! Obviously don't get it on yourself! Bleach in your eyes won't do you much good either, where would you stop?

 

[Hugh Jaleak]

Well yeah, that's the whole idea, dissolves organic matter like hair! Obviously don't get it on yourself! Bleach in your eyes won't do you much good either, where would you stop?

Issue is though, quite often it doesnt.... Often by the time it gets anywhere near where it's needed, it's so dilute its practically useless.

It has also been known to melt the pipework, Folks use it and it doesn't work so then they call someone out, who is then at risk as the Householder 'forgets' to mention what they've used. Bottom line is its dangerous, is sold openly to many folks who have absolutely no idea actually how lethal the bloody stuff is, (and some that do know use it to seriously injure and disfigure others).

I think the majority opinion among the Pro's is, it should be banned. There are better and more effective ways of cleaning out pipes that dont involve concentrated acid.

 

[Celeronmanuk]

Issue is though, quite often it doesnt.... Often by the time it gets anywhere near where it's needed, it's so dilute its practically useless.

It has also been known to melt the pipework, Folks use it and it doesn't work so then they call someone out, who is then at risk as the Householder 'forgets' to mention what they've used. Bottom line is its dangerous, is sold openly to many folks who have absolutely no idea actually how lethal the bloody stuff is, (and some that do know use it to seriously injure and disfigure others).

I think the majority opinion among the Pro's is, it should be banned. There are better and more effective ways of cleaning out pipes that dont involve concentrated acid.

A lot of household chemicals are dangerous, e.g. acid toilet cleaner used with bleach (really nasty)!! And oven cleaner has the same ingredient! Also caustic soda is a strong alkali not an acid.