Problem joining trap to sink waste, help appreciated

[scorchednickel]

Hi all,

We are building a hairdressing salon for my wife in our extension and I have just encountered a problem trying to attach an extendable waste trap to the sink waste.

I have attached a picture of the sink waste, thought it might help. Essentially, when trying to attach the trap, there is just not enough bite on the thread to attach. My understanding is that the bottom of waste should be hollow? Hands up, I am an amateur at this. I had a plumber install the hot and cold feeds, and waste adjacent to where the sink is being fitted and I thought it woud be a fairly easy job to just connect the two together. This has stumped me though.

Any ideas?? I would be very very grateful for your expert advice.

 

[terryplumb]

Does the sink have an overflow ? What size is the trap 1 1/2 inch or 1 1/4 inch? Pics of trap would be good. Is the brass thread so long that it is preventing the trap connecting ?

 

[JimCrow]

Screw this on to the grating then the trap.
https://www.screwfix.com/p/mcalpine...gclsrc=aw.ds&dclid=CPzdpt2Yid4CFa8h0wodPcAMgg

 

[scorchednickel]

Terryplumb thanks for the response. No overflow, and it's 1.5".
I think though that Jimcrow has the answer, this should extend up enough to give me purchase on the waste.
God I love the Internet, and good people like yourselves. Thank you guys.