Bathroom Waste Design

[matthew tubbs]

Planning a new bathroom, can anyone see any issues with this waste water design?

I plan on using 50mm solvent weld pipe and can achieve the correct fall from each appliance to the soil pipe.

I already purchased the basin that came with a waste trap, I am not sure if it is anti-vac or not so have provisioned for an air vent to stop gurgling.

 

[Jackrae]

If you are using 50mm pipe with self draining slope then it's unlikely you'll need an air vent as gurgling will only occur if the drain line is completely full, sufficient to produce a syphon effect. Neither the sink nor the shower will be able to fully fill a 50mm line and it's very unlikely the bath will as its outlet is less than 50mm (after you consider the loss of area due to the metalwork lattice). Just make sure the swept T where the bath joins the shower waste is as far from the shower as possible.

 

[Newboy]

Wherever possible you should avoid combining wastes and keep runs as short as practicable (there are no dimensions on your plan)
Your vent (AAV) should be at the start of the run and needs to terminate at least 300mm above the height of the basin rim.
Where your waste enters the stack it will need an offset from the WC waste connection - it can't connect directly opposite.
If you are going to combine the runs then 50mm pipework is OK subject to maximum run lengths.

Don't forget to allow for access points to make unblocking simple in the future.