Sink in bedroom not draining

[Mandi2247]

I have a sink in the bedroom the waste pipe is connected directly to the bath waste on the other side of the wall. Sink does not drain. I have removed the trap and the pipe down to below the floorboard. There is no clogs and if I pour water directly down at any stage of the connections it drains away fine. As soon as I add the trap piece and turn on the water it doesn’t drain again unless I disconnect the pipe from the trap ??
Any ideas please

 

[snowhead]

It'll be partially blocked close to where it joins the bath waste.
The blockage will be a mixture of hair, skin and soap.

You might move the blockage by filling the sink and using a plunger and the weight of the sink full of water behind it.
Alternately you may clear it with a spring waste pipe clearing tool.

CAUTION ,if you plunge there's a slight risk of blowing the waste pipe joint apart and causing a minor flood.

 

[Deleted member 120897]

The bath runs freely I take it?