Bathroom waste pipes to rainwater downpipes?

[andrewpreece]

Dunno about present practises, but loads of houses run their rainwater and bathroom pipes together in a hopper and combine them in a single downpipe - my 30's house does this. Can't immediately see the problem, except perhaps if you unplugged the bath in the middle of a torrential cloudburst, the hopper might overflow: how often could that happen and what could the worst consequence be?!!! Even if you divert rainwater from the downpipe to a barrel for watering the garden in dry spells, grey water from the bathroom is ok for this purpose too,

Andy.

[andrewpreece]

If you house is old then I assume that your rainwater presently comes down a downpipe, goes into a hopper halfway up and is combined with the bath/shower/sink waste. This feeds to a gully which enters the main sewer pipe. Your toilet waste comes down a sealed ( probably cast iron or steel ) pipe, open at the roofline for ventilation, which also feeds into the main sewer pipe. All waste water goes in the sewer, rain, bath and toilet. You pay an element in your water rates for removing 'surface water'. If you add another bathroom you won't change the status quo by adding in a new hopper. I hardly think the building police are going to come around banging on people's doors telling them to dig soakaways and move their rainwater downpipes to these! That's my common sense take on things anyway. I await a dawn call from the building inspector telling me my house is not to current regulations, and I have to dig soakaways, remove all the single glazing, add in double-check valves, put 18" of insulation in the loft, get rid of my fuse-wire consumer unit, and underpin the foundations which aren't big enough!

Andy.

[Pecanfan]

I'm currently installing a new bathroom where a kitchen used to be and by the looks of it, the only straight forward way of running the bathroom waste (shower, sink & bath) will be to run everything to a new hopper in an existing rainwater downpipe. I'd prefer to run it to the soil pipe but I think this will be impractical due to the various angles, heights etc. HOWEVER, according to the 'Wickes Guide to Plumbing & Downpipes' (or whatever) it says bathroom waste should NEVER be run into rainwater pipes. I can see the point to this if you're on a split rainwater / sewerage system, but this is an old house and everything leads to a combined sewer anyway.

I gather there's no other technical reasons for NOT running waste (not soil, obviously) to rainwater pipes?

TIA,

Andy

[andrewpreece]

double-check

I don't mind filling the cavity walls with rockwool if it comes to it, but

18" of insulation in the loft will turn it into an unusable bouncy castle affair!

Andy.

[Dave Jones]

Providing it leads to the main drain and not a soak away there should be no problem.

[Mike]

Nope

Nope again

They're thinking of it. Proposal is that when a house is sold, or when more than £8000 of work (i.e. a new kitchen) is done to it, the energy efficiency of the house must be increased by 10% of the cost of that work, or brought up to current part L requirements. This isn't approved yet and there are obviously all sorts of problems (listed buildings is one) but the UK won't meet it's Kyoto goals without it.

[Lurch]

On Tue, 28 Dec 2004 14:31:34 -0000, "andrewpreece" strung together this:

You've got it wrong there.

In the olden days rain water and foul water were sent down the foul water drain, you can do this nowadays which is the opposite of what the OP wants to do.

Most modernish houses have seperate rain and foul drains to cut down on sewage treatment costs by sending rainwater to surface drains.

I would only connect the waste water to foul drains and rain water to rain water drains.

[Liam]

replying to andrewpreece, Liam wrote: Don?t get anybody?s knickers in a twist regarding insulation levels in a loft, there?s no recognised improvement in values over 270mm so even the usual cautious building regs state a maximum of 290mm is achieved; basically

100mm between joists the 200mm across them means any more won?t improve the effiecincy