Drainage for washing machine /sink

[jasonbriggs]

Sorry not sure which section to put this in as it concerns several area.

This is the situation, we have a fairly old house, that used to have an old wash house and coal shed. In the 'out-house' there is an internal drain, it appears this runs under the concrete floor, to connect to an outside toilet, then onto an out side drain that the main guttering runs to.

Now our understanding is, that since we have (and in process of) converted this to a utility room that we cannot have an inside drain, which we don't want anyway.

What would be the best approach to redo the drainage?

For this sort of work do you need a specialist or are any regulations that you must follow?

And finally, how on earth would it connect into the existing system.

I have included a rough diagram below to show it easier with how I thought of solving the problem:

Untitled

• jasonbriggs
• 30 Jun 2008
• 2

Can anyone help?

Pointers to DIY guides or a company who could have a look at it and give good advice.

Thanks in advance.

 

[Space cat]

Don't assume anything about the way the existing drains run. Do you have any inspection chambers with lids you can lift? A look inside these will give you good clues as to how your drains work.

Drains underground tend to follow straight lines so all you have to do is project backwards from the inlet(s) of an inspection chamber to work out which drain(s) run into it. Confirm this by pouring a bucket of water into the drain(s). In particular, you want to find the final connection to the main sewer. Note that some houses have separate drains for sewage and rainwater. In this case there will be two final chambers.

PS: Don't be put off. Drains may be dirty and smelly but they're not difficult.

 

[jasonbriggs]

Hi,

Thank you for the reply.

We have tested the route of the drains by pouring water down them to see where they flow too.

The drain system is seperate from main house sewage system.

It was basically a system designed for rain water from the shed, a wash room and an 'outside' toilet.

They connect in a simple line, an outside small square drain where the gutting empties into, then on the inside of this wall another identical square drain that a sink or washing machine emptied into, then finally about 5meters in straight line from there the toilet.

This then directly connects (somehow) underground to another outside drain, which the kitchen sink and house guttering flows too.

The out house drainage is all under at least 12 inches of solid concrete, the toilet was removed by a builder, however we have since learned that he 'capped it' by using a plastic bag over the end of the soil pipe and concreted over it.

We belive that this may be causing a partial blockage in the system and the old internal drain is not allowed anymore.

We have had a builder and plumber round to have a look and assess the options. Short of breaking through the concrete to have a look there isn't much visible.

My suggestion was to abandon the the drain system and install one that is runs outside of the buildings, removing the need to break through the concrete and create a fresh, more easily accessible system, it starts and ends the same place, just takes a different route.

I just didn't know how much work was involved, any regulations, or if there was any tips anyone could give.

 

[Symptoms]

Jason - you need to find the inspection chamber (manhole cover) that all of this lot flows into - you don't show it on your plan or mention it in either postings. Unless you observe flow in this chamber how do you know there's a blockage? Systematically pouring buckets of water (coloured maybe?) at each gulley & observing flow at the IC is required. You could always scope (TV camera inspection) the drain run to determine any damage/blockage but my guess would be, unless the water test reveals a problem, the builder only wrapped or plugged the clay spigot before concreting so maybe no blockage. Is the concrete floor all new or just a patch where the old bog was; if just patched why not cut this small section back then cap the drain properly (plugs are available to do this). Anyway, getting a scoping crew in would be a lot cheaper than all that new work.

So if you have flow from the outside gulley to the IC my advice would be cap the internal gully with a sealing plate (metal) or a sealed rodding point then discharge the sink & washer through the wall and into the existing external gulley via the appropriate waste pipe(s). IMO as you aren't changing the existing drainage (just capping one gulley) so can do this and stay within the regs.

 

[Space cat]

We belive that this may be causing a partial blockage in the system

Do you have some evidence of a blockage? Does it affect all three drains in your drawing?

It's just possible that the builder allowed bits of broken toilet to fall down the pipe before he capped it off but I would always eliminate the easy options first. Lift the grates and, with a nice thick rubber glove, scoop out the gulleys below.

You should find that each one has a large S bend built into it, very much like the one you find on a toilet outlet. Clear them out until you can feel the lip at the top of the S. As an added bonus, the position of the S bend will tell you which way the pipe runs.

You still need to find the inspection chamber(s). If there is a blockage you'll have to rod it, for which you need access to an open pipe end.

So if you have flow from the outside gulley to the IC my advice would be cap the internal gully with a sealing plate (metal) or a sealed rodding point then discharge the sink & washer through the wall and into the existing external gulley via the appropriate waste pipe(s).

I agree.

 

[jasonbriggs]

Hey,

Thankyou for the replys again.

Okies the IC, is located at the front of the house, in next doors front garden!

We have isolated the partial blockage to the outside in the following ways:

The inside sink drains correctly to the main outside drain.
This main outside drain empties fine.
The outside drain for the guttering drains, but if very heavy rain the drain inside fills up.

We did dig out a load of mud and leaves and general crap and seemed to be ok but it started to back up again. Some days there can be a bad smell too.

We think, as the system is fairly old (there is actually an aspestos pipe there too) that there could be a cracked pipe by a root, or something blocking the pipe as everything before the old toilet doesn't flow correctly, but after where the old toilet connects to the system everything flows properly.

We were trying to save some money when trying to convert the old out houses to a utility room. The outside drain had been buried in the garden, we didn't even know it was there. The inside drain wasn't ever really used, it was just there in the corner of an old storage shed. The outside toilet wasn't ever really used. The main drain used to have the kitchen sinks and washing machine emptying into it.

We then knocked walls down in the outhouses, found the outside drain cleared it out and had the whole floor concreted, covering over the old toilet and leaving the inside drain clear.

We emptied the outside drain and then had the guttering for the outhouses run to it. The inside drain was then used for the washing machine (and in the future a second sink).

The builder said this would be fine and concreted everything, we then startd to have problems, the inside drain backing up and 'pooling' and the smell.

We have had people round to try and shift things, but they said they can see or feel anything down there and would need to start breakin throught he concrete to see further.

We thought rather than trying to rely on old dodgy stuff it might be better in the long run to put a new system in to keep all the drains out of the house and accessible.

If you need a better diagram of what is going on and where the IC is a can make one.

Thankyou for you help, I know what is like trying to help solve a problem without being able to see it!

-Jason

 

[Space cat]

It's pretty clear that the blockage is in the vicinity of the old toilet so, as I suggested earlier, it might have been caused by the builder letting broken bits of toilet fall down the pipe before he capped it. Did the inside drain flow freely BEFORE you had the toilet taken out?

You'll need to look inside that IC. Do all the drains you've mentioned so far empty into it - and, if they do, through how many different pipes? I'm surprized that there's not another one closer to the actual drains. (Concreted over perhaps. ) Your least invasive option is to rod the drains from the nearest IC. (Rodding upstream isn't ideal but it's better than nothing.) Ideally, you'll be able to push your drain rods all the way up the pipe and dislodge the blockage.

If this isn't an option, your next best bet will be to break through the concrete where the old toilet was, uncap the pipe and take a look inside. That'll be a whole lot less work than laying a new drain.

PS: I hope you're on good terms with your neighbours because shared drains can be trouble!