Bathroom sink won't drain. Help!

[RevengeOfTheRoundRobin]

I've thrown every chemical imaginable at it! I'm surprised it hasn't disintegrated. I've been trying for over a week and it still won't drain.
Shop bought drain cleaner.
As above plus bleach.
Sodium bicarbonate and salt and hot water (over heated and now the plating has bubbled up)
Vinegar.

I tried with a snake but don't know how to get it around the 90 degree bend.

Help!

Can’t you unscrew the u-bend under the sink? Put a bucket underneath first. Wear rubber gloves, it will be full of slimy hair.

You need a rubber plunger and give it some welly. The foaming unplugger powders are good. failing that you take the side off the bath and unscrew the u bend connections. The blockage is most likely to be there. If its further down the drain you need to lft the insection trap to see if its full of water. If it is rod it or call a plumber

We tried the plunger. Nothing happened, it just flooded the floor through the overflow of the overflow.

There is no u bend. It's a sideways T shape. I tried to unscrew it but didn't manage to get it apart.

Eww it’s full of hair and gunk

Mainly cardboard and toilet paper [glares at DS] But with the amount of chemicals it's had down it, it should have dissolved by now!!

I wonder if there's something solid in it? Maybe you need to call a plumber.

You cover the overflow and plunge

What you need is a wooden skewer. A long one. Approx 20/ 30cm.
Press down plughole cautiously until you feel a little resistance.
Twist very gently until you feel you have a grip of something. Pull out a giant sulphuric smelling rat of hair. It must be wooden though, metal or plastic won’t work.

This is what it looks like. It drains very, very slowly down to just below the level of the plug lever. The trap (?) at the bottom is not blocked, I've pulled stuff us with long tweezers and fished around with the drain snake and nothing is coming out. But I can't get it down the 90 degree turn into the wall, nor can I figure out how to dismantle it!

Does it have a slot on the bottom where you insert a 2p coin to twist ?

Perhaps one for @PigletJohn 's expertise?

No, it's flat.

which country are you in?

don't know. I'd expect to see a screw-ring to undo it at your "?"

perhaps it's a push fit.

If you undo the "unscrew" parts so the bottle trap is no longer fixed to the basin, you could turn and pull it.

the horizontal pipe is a poor design as detritus can collect in it.

I suppose the pipes have been hidden in the wall and tiled over to protect them from any risk of simple repair.

Plumber and watch what they do so you can remove it yourself in future

Plumber and watch what they do so you can remove it yourself in future
I had wondered that, also thought of also going to "look" at new sinks in a showroom and ask how to dismantle it!

I'd expect to see a screw-ring to undo it at your "?"
Me too, that's why I'm a bit flummoxed. There doesn't seem an obvious way to get it out. I don't want to damage it, and assumed I'm missing a trick. Google is no help, it brings up u bends and I know how to sort them. Do you know if this type of drain has a specific name?

is a poor design
I totally agree! It doesn't make any sense to me.

Try caustic soda (not bicarbonate). Homebase and places like that sell it. It's powerful stuff so be careful and make sure the window is wide open. If that doesn't shift it you need a plumber.

What happens if you plunge while covering the overflow? (needs to be covered fully to get a vacuum going with the plunger)

If you get a plumber make sure you tell them that you’ve poured a load of chemicals down there. They can cause severe burns and are not really recommended.

You need to take the pipe apart or plunge with the overflow covered. Try stuffing a damp cloth in the overflow.

I swallowed my pride and asked the neighbour. Feel like a right idiot. I couldn't get it off because I was trying to twist it off. You have to pull it straight out from the wall. There are pins so you can't turn it at all.

It is clean and drains again. The cardboard, plasters, foil tops from toothpaste and the plastic tags from tissue packets are out.....now I'm just waiting for DS to get home....