Why did drainpipes used to have a box on the wall?

[Commander Kinsey]

Why did drainpipes used to have a box on the wall, some sort of overflow if blocked? See link below for an example photo.

[NY]

It might have been to avoid sewer gases from flowing up the drain pipes from sinks if the water in the U trap got blown/sucked out. I'm not sure why it was fairly common (or even universal) for older plumbing but is very rare on modern plumbing, even on houses with external drain pipes.

I will make a confession. When I was very little (maybe around 5 years old) I used to have an infatuation with plumbing, and knew various houses on my walk between home and school not by who lived there but by the pattern that the pipes made on the wall. Embarrassing to admit such nerdy behaviour! There were some houses that had steeply-sloping pipes from sink/bath directly into the vertical soil pipe, but which had a second pipe that branched off the sloping pipe and entered the soil pipe higher up. That always intrigued me. I wonder if it was a way of avoiding the U-trap water from being sucked out.

It was even done for rainwater pipes:

shows the pipes from three gutters draining into a common pipe, with two of them going into a hopper and another going into a side branch of the down pipe.

[Commander Kinsey]

Perhaps the venting wasn't so good in those days? Although I don't see why, the vent pipe sticking up to roof height has always been pretty much the same.

Sounds sensible to me. When the mind is doing nothing during your walk, it's going to think about something.

That makes sense, a smaller version of the big pipe that's usually placed just after a toilet. When the sink finished emptying, the water flowing through that steep pipe and filling it's whole diameter, would suck the air behind it. But the extra pipe allowed air in from higher up instead of pulling on the u-bend water.

I don't see the point in that. If the downpipe became blocked, all that does is make loads of water pour out of the box instead of just spilling from the gutters over a wider area. I'd say it makes the problem worse.

[Commander Kinsey]

What's the advantage of your waste spilling all over the garden instead of just not leaving the bath?

[Commander Kinsey]

If the pipe is blocked and you empty your bath, then if you have a box, the water goes everywhere outside. If you have no box, the bath just stays full and you call a plumber. The second one is preferable obviously.

[charles]

I still have them. It provides an air break to prevent feedback.

[Commander Kinsey]

Good point, I hadn't thought of roof water going into the sinks and baths.

[Brian Gaff (Sofa 2)]

Do you mean a hopper with the pipe going into it? I still have one on my upstairs sink. Two possible reasons, Somewhere for noxious fumes to come out, and a simple way to allow for blockages as you suggest. My drainpipe has a cranked piece of pipe going up above the gutter to take the fumes away, but it only takes stuff from the toilet and one would not want an open hopper on that near a window, but for drains from baths and sinks its ok usually. Incidentally, I live in a terrace of four houses, but only the end two have drains from the gutter, resulting in, when it rains heavily it cascading down on right angled bends near my inset porch. I put in an extra drain pipe here into a soak away, however the shrub loved the water so much, a camellia, its now taken over the soak away and we get a nice little flood by the front wall. Brian

[Commander Kinsey]

I always thought of soak aways as a crazy idea. You're taking rainwater and putting it into the ground, so achieving nothing. Myself and my next door neighbour have the complete opposite. A hole in the ground with a pump in it. Which pumps water out into the drain to lower the water table in the garden so things aren't so soggy.

[Commander Kinsey]

What is? It's not clear what you're referring to. And stop deleting the newsgroups. uk.d-i-y re-added, which is where Jim is from you Canadian f****it.

[Commander Kinsey]

WHY do you CAPITALISE for NO reason?

And nowadays we do have seperate piping. Costs more to install two sets of pipes under the road, but saves money having to clean less waste, but when someone connects something to the wrong pipe as I've done for convenience, sewage goes into the sea.

P.S. you just replied to someone in a uk group and removed that group, so he didn't see your reply. Fuckwit.

[ARW]

There is some suggestion on certain web sites that it is to increase flow rate.

[Commander Kinsey]

How would that happen?

[Xeno]

In this country (Aus) the sullage and the sewerage are kept separate. The sullage lines go out into the street stormwater drains. They are

*not allowed* to be connected to the sewerage lines. The sewerage lines, using separate pipes, are plumbed into the sewerage system. If the sullage were connected to the sewerage, the sewerage treatment plants get flooded bigtime because when it rains here it really pisses down.

I suppose we use what you would call a two pipe system. There is talk here of introducing a new third pipe for greywater. That is, water that comes from baths, sinks, showers, etc. as opposed to sewerage from toilets. Difficult to retrofit of course but new estates are likely to be plumbed this way in the near future.

[Xeno]

What??? You already have a *sullage system*. It's more commonly known as a *storm water system*. The street drains feed into it and that's where household sullage lines should also feed into. The sewerage is and always should be separate (note spelling).

How to win friends and influence people.

[Xeno]

The air break will assist in that.

[tabbypurr]

This country is in fact the UK, hence the uk in uk.d-i-y, and we don't do things that way. Millions of old houses put the whole lot down the sewage system.

[Commander Kinsey]

When did two pipe systems start being used? Because I was surprised to see sinks sharing a pipe with rainwater on a building which I don't think is all that old. Hopefully it goes into the sewer and not the rainwater drain.

[Commander Kinsey]

Don't most people do a shit a day?

[Commander Kinsey]

alt.home.repair is in America you fool, it's sent to two newsgroups.