Sink filling up then draining out slowly - please help

[hk123]

Hi everyone,

I would like some help with an issue I have. I had a extension done last year with building control all certified.

Over the past 3 weeks the water in the sink has not been draining quickly after taking off the kitchen cabinet plinth, I can see the problem the builder used 40mm pipes all around the kitchen until the drain and he has not added a vent. See Diagram below with lengths.

We have cleaned the pipes with a garden hose and there was lots of debris built up, also cleared the trap and I have also put an AAV but still the the water in the sink is draining slow. Finally even when the dishwasher is turned on the water fills in the sink first before draining.

Any ideas how I can solve this as my builder is not being helpful at all and not taking responsibility.

Thank you

Hiten

 

[Best]

Nothing to do with not having a vent on it. The problem is it shouldn't have as long a length of mere 40 mm pipe and at a slight fall.
You need to have proper gulley/soil pipe 110mm closer

 

[JCplumb]

Think the limit for 40mm waste is 3m. The limit for 50mm is definitely 4m. You can stretch the rules a little providing you have an AAV and rodding points.
As above, you'll get great results from a 4'' waste, but you might get away with a 50mm if that's not feasible.
The fall needs to be between 1 and 2.5cm per metre. Your falls are a little steep but better than too shallow.
The hose pipe might not shift grease, have a go with some soda crystals to shift it. Follow the instructions on the pack.

 

[Chuck]

Drains from kitchen sinks and dishwashers always to block with fat eventually, it's only the frequency that varies. You can reduce the frequency by using shorter runs and larger diameters and trying to train your family not to let fat go down drains (good luck with that BTW...) but eventually you'll need the rubber gloves and some strategically positioned rodding points. If you manage to keep your 40mm clear you'll be rewarded by having to dig rancid fat out of the gulley. So, design for easy maintenance.

 

[king of pipes]

as above the pipe work needs to be 50mm you maybe able to clear the blockage with a ropump I HAVE THE VIREX VERSION its like a giant plunger that shoots a jet of water down the pipe , failing that there is a product called one shot which will dissolve the blockage but BEWARE ITS SULPHRIC ACID BASED AND WILL TURN CHROME BLACK SO PLEASE , PLEASE WEAR GLOVES AND EYE PROTECTION AND FOLLOW THE INSTRUCTIONS regards kop

 

[hk123]

Thank You For The Responses. I removed the trap and with a garden hose cleared out the pipes I had the water running for 10 minutes but I'll try the soda crystals or something stronger. Also can I have the 40mm go into a 4m 50mm Where would you suggest I put the AAV on the above layout?