Can I connect a drainpipe to a soil pipe?

[Another Dave]

I've got a 1928 house (detached) and the drainpipe from the roof gutter goes into a soakaway. It doesn't soak away very well and the rear corner of the house often has a puddle against its wall. This doesn't seem a good idea to me.

About 60-70cms from the drainpipe is the soil pipe for the upstairs bathroom. The waste pipe from the shower/bath is joined into this and the whole lot goes to the main sewer.

Is there any reason I shouldn't also join the drainpipe into this?

If I can, what's the best way to do it?

Another Dave

[Bob Minchin]

Talk to your sewage processor - usually the clean water supplier but not always. A few years back there was a rebate scheme to householders who did NOT send their surface water into the main sewer. You property might be one of those.

Going back a long time, there was a move to encourage surface water to go to the sewers to give better flushing of the system. Now with higher density of housing and higher water usage, the surface water can become an embarrassment in the system hence the "bribe" paid to those who used soakaways for surface water.

[John Rumm]

Depends on the area, some have combined sewers designed to take sewage and surface water, others stipulate use of separate surface water systems or local disposal (e.g. soakaways).

Your local building control department will be able to tell you which applies.

Some local authorities get a bit peeved with too much surface water being directed into the sewer and then causing that to overflow.

with a trap would be best... however it sounds like you may end up with a column of water sat in the pipe. While that may work with soil pipe that has tight fitting O rings at all the joints, its likely to leak out of a typical down pipe joint.

(I would however recommend avoiding the technique I discovered someone had used in my place... taking a square section down pipe into the end of a 110mm soil pipe. plugging the gap with a plastic bag, and then burying the lot under a patio!)

[Tim Lamb]

Why not locate the soak and clear it?

Usually the pipe discharge point is surrounded and plugged by black soil from decayed leaves/moss in your gutters.

A temporary cure can be as simple as feeding a garden hose and jet nozzle down the pipe until the obstruction is reached.

If surface water was allowed into your soil system, I expect the builder would have done it:-)