Pumped shower waste

[primetime]

Hi all,

Am planning the loft bathroom and have a few initial questions. I want it to be a wet room style so won't raise it from the existing floor level and also don't have a lot of head height to play with.

The layout won't allow a waste pipe to fall to the soil pipe as I can't go through the joists or underneath. As mentioned above I don't want to raise it.

Option 1 would be to go through to the ceiling below and box in - not ideal.

Option 2 is pumped. Having a quick look around I have a few questions.
a. Does it matter which mains power supply I use? ie lights, sockets, independant?
b. Does it need it's own isolator installed?
c. Does the pump unit sit in the bathroom itself?
d. Some of the pipework appears to be 22mm on some units. Can this be run directly into the soil pipe/vent stack?
e. Is there a minimum distance the pump needs to be from the trap?

Thanks.

 

[muggles]

For a pumped waste, you can spur off a socket ring main (definitely NOT the lights) and you should install a switched fused connection unit containing the correct rating of fuse for the pump.

The pump normally goes in the bathroom, with a transformer elsewhere as they're usually low-voltage.

The pipework size and distances from the trap and to the stack vary from unit to unit. You should consult the manufacturers' instructions for the unit you intend to use. I'd recommend the Whale Digital Smoothflow pumps, which precisely match the flow rate of the shower to the pump rate of the unit, thereby significantly reducing pump noise. Cheaper models tend to suffer a lot from suction noise

 

[primetime]

Thanks muggles. Have had a look at the installation instructions for this and looks good. Also came across the dry-deck 20 kit. Any reason for choosing the smoothflow over the dry-deck?

 

[muggles]

The dry deck kit will be fine - sorry, didn't spot that you'd said it would be a wet room