Main downpipe on rear of house doesn't go into drain, expensive to fix?

Bendy_House

By the looks, the WHOLE of the rear roof of your MAIN house drains on to the sloping roof of your extension - that will be a lot of water.

Then there's what appears to be your neighbour's extension roof also emptying on to your extension roof on the left as seen in that pick. So, you have half your main house, all your extension, and half your neighb's extension to cope with. Gulp.

Even if you could physically do it - and good chance you could ( what's inside your extension?) - I understand you wouldn't be 'allowed' to run that rainwater into a foul-water system.

Since the GUTTER height is comfortably above lawn height, there is almost certainly a solution possible by diverting the DP at a much higher level, and taking that down your garden to some form of soakaway (or feature pond...). But, frankly, I'd like answers before proceeding - such as how did that neighb get away with draining on to 'your' inadequate system in the first place?

I'd want a builder to view and assess as part of the buying process. 

stuart45

First check is with local Building Control to ask if it's a combined system and they will allow this.

t1redmonkey

Bendy_House said:

By the looks, the WHOLE of the rear roof of your MAIN house drains on to the sloping roof of your extension - that will be a lot of water.

Then there's what appears to be your neighbour's extension roof also emptying on to your extension roof on the left as seen in that pick. So, you have half your main house, all your extension, and half your neighb's extension to cope with. Gulp.

Even if you could physically do it - and good chance you could ( what's inside your extension?) - I understand you wouldn't be 'allowed' to run that rainwater into a foul-water system.

Since the GUTTER height is comfortably above lawn height, there is almost certainly a solution possible by diverting the DP at a much higher level, and taking that down your garden to some form of soakaway (or feature pond...). But, frankly, I'd like answers before proceeding - such as how did that neighb get away with draining on to 'your' inadequate system in the first place?

I'd want a builder to view and assess as part of the buying process. 

Thanks, yes this is why I'm posting really - there is a LOT of water to handle which is presently just being dumped on to the concrete ground and not into any drainage system.  It's not as if it's just a standalone conservatory downpipe or something unfortunately!

I did notice about the neighbour's downpipe also going into this house's guttering which I did think was a bit strange.

The kitchen of the house is inside that single storey extension.

I get what you are saying with diverting the guttering higher up, but then that would create some sort of 'mid air' guttering system.  Since it would have to bridge across the single storey extension roof, across the small concrete 'patio' directly in front of the rear door, and then onto the lawn area. 

And the lawn area is all sloping downwards towards the extension as well (that's another thing you probably don't get the perspective of from the photo, the garden on the higher level is actually uphill so any surface water would actually run towards the house and it's non existant drainage!).

I may have to reconsider buying this place!  Everything else about it is quite nice for me compared to a lot of other places I looked at, but the drainage situation here does seem a bit difficult to workaround

t1redmonkey

aoleks said:

you need a soakway, can be a DIY project. carefully dig a 1x1m box, place some creates in there and you're nearly done.

Soakaways: What are They & How to Build Them | DIY Doctor

The soakaway as it's described in that article wouldn't work for this house, the bit directly in front of the rear door is only about 1 meter, and then you have steps/a wall seperating that from the lawned area which is on higher ground.

stuart45

Is.the drain an open gulley?

Bendy_House

You have a kitchen in that extension, so that means there is a 'foul water' drain near there. So, try what Stuart suggested above.

In the scheme of things, this is relatively trivial, in that there is almost certainly a number of solutions. It's not like the roof is falling on, or the house sinking...

Ie, if the house is OTHERWISE a good box-ticker for you, then ask for a builder to view. Or, pass the buck - insist the vendor sorts this or else you may have to pull out.

What type of roof does your extension have?

t1redmonkey

stuart45 said:

Is.the drain an open gulley?

Not sure.  Annoyingly, I went back to it yesterday to poke my head into the loft.  I wanted to go to the rear to look at the drainage, but the vendors had placed a washing machine RIGHT in front of the rear door!!!  I was about to move it and the estate agent told me not to move it in case it 'marked the floor' because if I changed my mind, it would annoy the vendors if I also damaged the floor.

t1redmonkey

Bendy_House said:

You have a kitchen in that extension, so that means there is a 'foul water' drain near there. So, try what Stuart suggested above.

In the scheme of things, this is relatively trivial, in that there is almost certainly a number of solutions. It's not like the roof is falling on, or the house sinking...

Ie, if the house is OTHERWISE a good box-ticker for you, then ask for a builder to view. Or, pass the buck - insist the vendor sorts this or else you may have to pull out.

What type of roof does your extension have?

Roof was a metal roof of some sort, I was thinking of getting that replaced with something more 'modern' if I bought it (but doesn't seem anything wrong with it at present, no stains/leaks or anything like that on the kitchen ceiling).

Now that you mention it, I did see one of these at the foot of the wall, sort of to the right of where I pointed to the downpipe in my photo, so this must've been covering the foul water drain (as it was basically on the other side of where the kitchen sink is): https://www.diy.com/departments/floplast-black-gutter-guard-l-305mm/35253_BQ.prd

But as I say, apparently there is an actual seperate drain below that arrow in my photo to the left of the door, but nothing is going into it at present for some reason.  So I'm guessing that this SHOULD be used for regular rainwater drainage, they just haven't configured the guttering correctly maybe?

Bendy_House

t1redmonkey said:

Bendy_House said:

You have a kitchen in that extension, so that means there is a 'foul water' drain near there. So, try what Stuart suggested above.

In the scheme of things, this is relatively trivial, in that there is almost certainly a number of solutions. It's not like the roof is falling on, or the house sinking...

Ie, if the house is OTHERWISE a good box-ticker for you, then ask for a builder to view. Or, pass the buck - insist the vendor sorts this or else you may have to pull out.

What type of roof does your extension have?

Roof was a metal roof of some sort, I was thinking of getting that replaced with something more 'modern' if I bought it (but doesn't seem anything wrong with it at present, no stains/leaks or anything like that on the kitchen ceiling).

Now that you mention it, I did see one of these at the foot of the wall, sort of to the right of where I pointed to the downpipe in my photo, so this must've been covering the foul water drain (as it was basically on the other side of where the kitchen sink is): https://www.diy.com/departments/floplast-black-gutter-guard-l-305mm/35253_BQ.prd

But as I say, apparently there is an actual seperate drain below that arrow in my photo to the left of the door, but nothing is going into it at present for some reason.  So I'm guessing that this SHOULD be used for regular rainwater drainage, they just haven't configured the guttering correctly maybe?

All guesswork at the mo', but that does sound more promising.

Does the water 'pool' ABOVE that drain cover (I wonder if the drain is blocked?)

Another viewing is in order, sans WM...

Nothing wrong with a metal roof as long as you like it's looks. But are you sure there's proper insulation under it? Was this extension signed off by Build Control?

Apodemus

t1redmonkey said:

stuart45 said:

Is.the drain an open gulley?

Not sure.  Annoyingly, I went back to it yesterday to poke my head into the loft.  I wanted to go to the rear to look at the drainage, but the vendors had placed a washing machine RIGHT in front of the rear door!!!  I was about to move it and the estate agent told me not to move it in case it 'marked the floor' because if I changed my mind, it would annoy the vendors if I also damaged the floor.

Hmmm....  That would set alarm bells ringing for me.  Being cynical I would be thinking that the vendors and the estate agent don't want you poking around outside!