What am I doing wrong? Sink and drainage!

[wherehaveallthegoodfolkgone]

Hi everyone, please can you shed light on to this nightmare situation.
I have a butler sink, no dishwasher. To prevent blocked drains I use a little strainer. But I still end up with a half full sink of dirty dishwater. I have had countless plumbers out, it just seems my drains flow slowly...the strainer makes it ten times worse. But if I don't use one, chunks of food will pass down the drain. We scrape plates but sometimes there's a bit left

Never experienced this in any other house.
Any wonder products or recommendations?
Many thanks

you need to look at the plumbing under the sink the angle and trajectory of that pipe. also check the air vent to make sure that isn't plugged full.

How do you clean your pipes and U bend normally?

Thank you both, I'll book in to see a plumber again then. So costly!
They've cleaned the gutter outside in the past and just unblocked from there. I used to have home serve but no longer.
I personally have tried filling the sink up with it plugged and then letting it go for pressure clearing.
Also drain cleaner...

Would you use the strainer?

Have you checked that the trap under the sink isn't full of stuff?

Is the plug hole always free of hair? I use a tiny bottle brush on a long flexible wire to keep plugholes clean in my house.

There’s a lot you can check yourself first. For example take off the u bend and ensure it’s completely clean and clear. If water drains slowly it can cause a build up of bacteria which forms a kind of disgusting brown slime and causes the water to drain even more slowly. Taking off the u bend is not difficult most of the time. There are YouTube videos if you aren’t confident.

Then once the u bend is off you could use a plumbers snake (very inexpensive) to try to clear any blockages.

I would try those first before paying a plumber to do the same.

Do you have standard size pipes or narrow ones? Some older houses have narrower pipes which clog very easily.

I've never ever used a strainer on my kitchen sink. Drains are supposed to be able to cope with the little bits that miss being scraped off. Agree with pp it sounds like your sink plumbing is blocked, try a drain snake or a few kettles of boiling water.

OK I would start by emptying the u bend and doing a regular flush to try to break down any build up in the pipe. For the pipes I tend to take the strainer out and chuck an entire kettle of just-boiled water down there, then a good dose of soda crystals (washing soda), maybe a cup of crystals and a little more water to activate them a bit. Let sit for half an hour then flush through with another kettle of just boiled water. Take lid of kettle off and pour quickly so it goes through as a bolus. Like your draining a whole sink of water through really but a bit more radical. You can also do this with bleach. If you don't want to do the kettles you could also pep up your sinkful of water method by using very hot water and a strong solution of soda crystals, or again a bit of bleach.

I can't take any responsibility for your pipes but this is how my mum taught me to clear pipes and I've been using it on bathroom and kitchen sink drains for years.

You do have to be very careful with using boiling water to clear blockages, because it can crack plastic pipes.

Thank you for the suggestions. I'll try to get my son to help with checking the u bend. Got a snake and long thin bottle brush