Condensate pipe fall

[easyt]

I intend to raise a new shower base on 75mm celcon block and 15mm ply. I will duct for a replacement boiler feed pipe and fire control valve line. Also running the length of the shower (1700mm) I will provide a 22mm condensate pipe for future use. (Present boiler non-condensing). The regs say 3 degrees fall which I work out at 1 in 21.2 meaning 80mm fall over the length. I will struggle to achieve this. If I ran this section of pipe (say 2m long) at say 1 in 26 would this be likely to cause a problem. After the 2m run it is less than 1m to the drain and correct fall is available. In this situation what would you see as a minimum realistic fall.

 

[MarkAqua]

It's not ideal. Can you convert to 32mm waste pipe instead?

 

[easyt]

The problem I have Mark is twofold. If the area outside was lower I could go out lower. However the only way I can fit the pipe is beneath a raised shower floor. To underside of the shower base I was looking to have about 100mm lift. If I lay the celcon blocks on mortar I reckon that would give me about 80mm. With 15mm ply bedded on mortar that would give me about 100 mm and with bedding for the tray I reckoned about 105mm to the underside of the tray. I assumed that the 22mm pipe was 25mm OD (?) leaving 60mm for fall. I should be able to go down 10mm on the exit level so that would be 80mm+10mm=90mm for pipe and fall. If pipe OD is 25mm then fall available is 90-25=65mm over 1690mm. ie 1 in 26. I must admit I am surprised that it needs more than 1 in 30 fall but I am no expert.

I suppose I could trim the underside of the ply board by 10mm over over the last 200mm (just 20mm wide and locally void the bedding at this location. That would gain the required fall of 80mm over 1700mm length.

Alan

 

[Robtheplumb]

Condensate pipe can be done in overflow pipe, this is 21.5mm od so you might get away with it.

 

[Blackcatgas]

Not perfect but itl be reet, if you ever have problems with it on your new boiler you could connect in a condensate lift pump below the boiler which will blast the condensate up to 5m verticaly.

 

[easyt]

Thanks All

Easy T