Shower waste depth of seal

[larold]

Am looking to buy new shower tray. It comes with ones of these wastes.

Untitled

• larold
• 1 Apr 2009
• 1

It has 90mm diameter connected to 40 mm pipe.
I wanted to make sure when I install it it meets the building regs. I looked in Table 1 in section 1 page 7 of document H1 Building regulations 2000 (2002 edition). It seems to indicate that for showers the min seal depth is 50mm.
I asked the seller about this and I am told that the min seal depth required is only 25mm not 50mm, and that this device is sufficient as it is 45mm.
I am totally confused because the seller then said that the "amount of seal in trap is not dependent on the depth of the unit".
What exactly is the depth of seal then?
If I installed this, would it meet building regs? Do I need to attach it to any other type of u-bend or can I just connect it to 40mm waste pipe?

 

[seco services]

min is 50mm on a shower discharging to a soil stack.

the 25mm is the amount of water seal that must retain in a trap after
evaporation or pressure fluctuations.

 

[larold]

thanks. what exactly is the 50 mm min then? I will be running a pipe to a discharge stack, where soil also enters. Do you mean I need a 50mm diameter pipe?

 

[seco services]

50mm water seal trap.

 

[larold]

Sorry if I'm being thick here, so the 50mm is the min depth of the trap and the 25mm is the min amount of water that has to be left in the trap?
If so, this is fine then, and I can just connect it with 40mm pipe straight to soil stack?

 

[seco services]

yes

 

[larold]

thanks