Downpipe issue

Jeepers_Creepers

Not 'defective', but the slope appears to be marginal at best. Even after a heavy downpour, there ideally shouldn't be pooling like that - the water should run off constantly.

As pointed out by others, some of this might be down to the debris on there, and that is just typical accumulation that'll collect over time - a yearly brush-off should sort it.

As long as your roof fabric remains watertight - and it should a for a good number of years - then this extra DP water shouldn't cause problems. BUT, that's not to say that what the neighb has done is acceptable - it isn't.

AN, can you explain where - exactly - that DP used to go, and why did the neighb change this? All I see beyond your porch roof is grass!

Please try and sort the 'issues' into those which are clearly unreasonable and unacceptable - smoke, cinders, altered DP, DIY noise beyond certain times, etc. - and those that should be accepted as typical terraced living. Keep the list factual and unemotive - they will have a far greater impact like this; "Smoke comes into my house whenever the wind is in a thingily direction, which is most times. I suffer from asthma, and can genuinely feel the effect this has on me...". "Smouldering cinders regularly get blown into my garden, and it's only luck that they haven't landed on things that could have been damaged by them, such as x, y and z.".

As soon as you go "I'm just FED UP of all his DIYing!", you will likely see eyes beginning to roll.

stuart45

Ponding on a flat roof will shorten the life span of the roof covering.

travis-powers

Section 62 my calculations 1 in 60 ideal 1 in 80 at a push.
As I read it in the ops post roof was fine no pooling next door has since diverted the down pipe to expel water from two pitched roofs onto this flat roof suggesting that op should have roof rebuilt to counter some dodgy diy is insanity

Section62

travis-powers said:

Section 62 my calculations 1 in 60 ideal 1 in 80 at a push.

Those are falls, not 'calculations'.

Avoiding getting bogged down in a debate about the applicability of Manning's equation, we can keep things simple by doing a straightforward CSA comparison.

Two brimful half-round gutters have a CSA of about 8000 mm2 combined.  If all of that flow could enter the downpipe (it can't) then it would equate to a flow depth of 8mm per metre width of the flat roof below.

I'd estimate the OP's flat roof is about 1.2m wide, therefore in a theoretical worst-case, the depth of water flowing across the roof from the downpipe would be about 6.7mm.

So what makes you believe that a flat roof can't 'cope' with (let's say) about 8mm depth of water flowing over it once in perhaps 50 years?  The water won't flood over the sides, and in terms of weight the designer would have allowed for more than a layer of (wet) chippings, plus occasional access by people and their tools.

More typical gutter flows would equate to a small fraction of 1mm depth of water on the flat roof. The amount is so small that it could legitimately be ignored for the purposes of roof design.

TL;DR - it really isn't a big deal from a technical POV, which is how BC will look at it.

travis-powers said:

As I read it in the ops post roof was fine no pooling next door has since diverted the down pipe to expel water from two pitched roofs onto this flat roof suggesting that op should have roof rebuilt to counter some dodgy diy is insanity

Maybe you missed the point that the OP has already had the roof re-felted and changed the way it drains. Maybe you missed the point that at least two people who know how a flat roof should work have said you shouldn't get ponding like that, regardless of the downpipe.

"Insanity" would be giving the OP the wrong advice that getting the downpipe removed will solve the ponding issue.  Unfortunately they will need to get work done on their roof, regardless of what happens to the downpipe.

AvivaNightmare

AN, can you explain where - exactly - that DP used to go, and why did the neighb change this? All I see beyond your porch roof is grass!

The downpipe (brown ) had a length of pipe that ran from it across his porch roof ( dark blue ) to a drainage pipe ( in red) that was built into the porch roof and down to meet drains, this is how all the houses on the estate were built,  he removed the red pipe when he converted his garage ( half of the white square ) into a room and blocked the hole that the red pipe ran too. The grass area is the top of his porch! 

AvivaNightmare

Buildings control have been in touch, they have confirmed he has never submitted any building regulation records for all the work he has undertaken to the house, they are contacting him, but with regards to the drainage this is not a BC matter. 
However I am hopeful that with contact from the BC team over the other work he has carried out, without regard to the impact on neighbours will make him more repectful and thoughtful over the work he carries out in the future. 
I will arrange for my porch to be cleared to hopefully help the discharge of water. 

AvivaNightmare

AvivaNightmare said:

AN, can you explain where - exactly - that DP used to go, and why did the neighb change this? All I see beyond your porch roof is grass!

The downpipe (brown ) had a length of pipe that ran from it across his porch roof ( dark blue ) to a drainage pipe ( in red) that was built into the porch roof and down to meet drains, this is how all the houses on the estate were built,  he removed the red pipe when he converted his garage ( half of the white square ) into a room and blocked the hole that the red pipe ran too. The grass area is the top of his porch! 

As can be seen on the row of houses behind me, where all 4 houses with downpipes have the drainage pipe in situ.

Jeepers_Creepers

AvivaNightmare said:

The downpipe (brown ) had a length of pipe that ran from it across his porch roof ( dark blue ) to a drainage pipe ( in red) that was built into the porch roof and down to meet drains, this is how all the houses on the estate were built,  he removed the red pipe when he converted his garage ( half of the white square ) into a room and blocked the hole that the red pipe ran too. The grass area is the top of his porch! 

Ah! Ok - I see now, thank you.

Wow - the audacity of the guy! The presumptuousness! The bludy nerve!

So, you both have pretty much identical porches and pretty much identical garages. He has converted his garage into living accommodation, and - whilst you have recovered your porch roof - he has 'grassed' his? And, whilst he had the responsibility for that downpipe, he has unilaterally cut the drain short and aimed it over your roof instead! He did this even tho' his garage roof is just as capable of accepting this flow as yours is. The cheek!

All he had to do - if he'd wanted to lose that 'red' round drain point - was to slightly extend that red d/p so it directed the flow a foot further on to his own garage roof!

Lawdie - this guy is a piece of work all right! I can't see any valid excuse for him.

Pleased to hear that BC are going to come out to investigate. I hope they have the tenacity to firmly lay down the rules and see it through. I suspect the stove will certainly be a problem for the guy, and I'd also be happy to bet that his garage (and lawd knows what else) does not conform to current regs. Hopefully he'll end up with a sizeable remedial bill, tho' sadly he'll probably just take on the updating task himself - more DIYing...

Based on what I presume is now the whole accurate picture, this is what I'd do if I had to conclude that the neighb was a complete chancer who only responds to force and not to reason, which appears to be the case here.

1) Wait until BC have reported. I doubt you'll get to see all that they report, but it would be nice to know! I think it would be fair of you to at least ask them if the stove flue would now be made HETAS-conforming, since this is causing you genuine medical issues and a genuine practical nuisance. If BC don't involve themselves in the DP issue, then it's up to you. So,

2) Either take this on yourself, or engage the LP on your insurance. It seems pretty clear and obvious to me that the changes this guy has made to his roof - covering it with grass and gravel (is that a deliberate attempt at a green roof, or just serious lack of maintenance?!), coupled with diverting the rain water on to yours - is causing, and will continue to cause, issues to your roof. Looking at your pic now, it's pretty obvious that most (all?) of the moss, gravel and other debris that's collecting on your new roof, helping to prevent it from draining properly, has been washed off his 'roof' and on to yours. He needs to take action to prevent that from happening from now on.

I understand the process is; send a 'put on notice' letter to outline the issues, and warning him of the consequences should he not resolve them. This in essence says, "I am putting you on notice that the debris coming from your porch roof is building up on my recently-recovered roof and is preventing it from draining properly (see photos). If you do not take action to prevent this from happening in future, I will hold you liable for all the cleaning-up costs and any remedial repairs that may be necessary. In addition, I have been advised that the additional flow of water from the downpipe that you have redirected on to my roof without permission is compounding this issue. I ask that you reinstate that downpipe's flow to its original, correct, location, and take action to prevent any further debris from being washed on to my roof from yours - I'd suggest some form of low parapet. If you fail to address these issues within 2 weeks of this notice, I will employ a tradesperson to clean my roof and to return the DP outlet to its original direction and will present you with the invoice for these works. If you do not voluntarily agree to pay for this, I will sue you for these costs instead. If you also do not take action to prevent any further debris from coming on to my roof from yours, I will re-employ that person to keep my roof clean as is required, and will again submit the invoices to you for payment, and will, if necessary, sue you for these costs."

NB I do not know if that is the sort of content these 'putting on notice' or 'letter before action' communications should have, but I'd imagine it is.

If you have LP on your insurance, let them handle this. If, after examining the issue they say "Yup - we'll take this on", then you are home and dry, and can sit back and enjoy.

Meanwhile, how to deal with neighb now you have taken action? Don't avoid him - you have done nothing wrong, but he has. Be super-calm, unemotive, look him in the eye, shrug regretfully and just say "What did you expect? You have taken advantage, you have shown no consideration to others - so what did you expect?" Then walk away.

Don't smirk, however tempting it may be... :-)

Section62

Jeepers_Creepers said:

All he had to do - if he'd wanted to lose that 'red' round drain point - was to slightly extend that red d/p so it directed the flow a foot further on to his own garage roof!

From a technical perspective discharging onto the lower flat roof is a better option than running the flow through a near-horizontal pipe.  Firstly due to the difficulties involved in supporting RWP at the correct fall as it passes over a flat roof, secondly because lengths of near-horizontal RWP are a magnet for debris and will be an ongoing maintenance issue.

Hence, as I suggested way back in this thread, BC have taken a look and decided "Nope, nothing wrong with that". Contrary to the expectations of those who disagreed with me.

Regardless of whether his other work is a 'bodge', what he has done with the RWP is what anyone with some professional expertise with drainage would have identified as the better overall approach. The outstanding question is whether he had a legal right to do it.

Jeepers_Creepers said:

It seems pretty clear and obvious to me that the changes this guy has made to his roof - covering it with grass and gravel (is that a deliberate attempt at a green roof, or just serious lack of maintenance?!), coupled with diverting the rain water on to yours - is causing, and will continue to cause, issues to your roof.

It looks like chippings to me. Covering a flat roof with chippings was (maybe for some still is) a standard technique with various benefits. It wouldn't surprise me in the least if that was how the roof was originally constructed.

What you believe to be 'grass' looks more like sedum to me.  It self-sets on chipping-coated flat rooves and is rarely a serious problem. In fact as you allude to, some people plant it to achieve a green roof.

Would I remove self-set sedum as part of regular roof maintenance?  Probably not, as the more you faff around on a flat roof, the quicker you make them leak. Just leave well alone is usually the better approach.

And if the diversion of the RWP was causing issues for the OP's roof then BC would have involved themselves.  They haven't, because it isn't.

Jeepers_Creepers said:

Looking at your pic now, it's pretty obvious that most (all?) of the moss, gravel and other debris that's collecting on your new roof, helping to prevent it from draining properly, has been washed off his 'roof' and on to yours.

I don't think that is "pretty obvious" at all.

If asked to be an expert witness in court I'd suggest it was most likely to have got there while the neighbour was working on the roof, but it couldn't be ruled out that a bird had been scratching around in the chippings looking for food.

It is a trivial issue (not one to go to court over), and wouldn't be a problem at all if the OP's roof had adequate fall towards the drain.

Jeepers_Creepers said:

I understand the process is; send a 'put on notice' letter to outline the issues, and warning him of the consequences should he not resolve them. This in essence says, "I am putting you on notice that the debris coming from your porch roof is building up on my recently-recovered roof and is preventing it from draining properly (see photos). If you do not take action to prevent this from happening in future, I will hold you liable for all the cleaning-up costs and any remedial repairs that may be necessary. In addition, I have been advised that the additional flow of water from the downpipe that you have redirected on to my roof without permission is compounding this issue. I ask that you reinstate that downpipe's flow to its original, correct, location, and take action to prevent any further debris from being washed on to my roof from yours - I'd suggest some form of low parapet. If you fail to address these issues within 2 weeks of this notice, I will employ a tradesperson to clean my roof and to return the DP outlet to its original direction and will present you with the invoice for these works. If you do not voluntarily agree to pay for this, I will sue you for these costs instead. If you also do not take action to prevent any further debris from coming on to my roof from yours, I will re-employ that person to keep my roof clean as is required, and will again submit the invoices to you for payment, and will, if necessary, sue you for these costs."

NB I do not know if that is the sort of content these 'putting on notice' or 'letter before action' communications should have, but I'd imagine it is.

Before going all barrack-room lawyer and encouraging the OP to sue, it might have been better to do as I did earlier in the thread and suggest the OP needs to look at their deeds regarding rights of shared drainage. If the neighbour has that right then considering the RWP serves a shared gutter, the legal argument about whether or not the neighbour can do what they have done is going to be complicated.

Secondly, if the OP does go legal, they will need expert advice.  You suggest they write "I have been advised that the additional flow of water from the downpipe that you have redirected on to my roof without permission is compounding this issue." - but this 'advice' is from some random people on an internet forum and is not only disputed here, it is demonstrably wrong by simple observation of the OP's own pictures.

Moreover, acknowledged experts (Building Control) have now looked at the situation and decided no action is required.  The neighbour's solicitor would point to this fact, the court would nod in agreement, and the OP would possibly get a costs award made against them for falsely representing the advice they had received.

If they go as far as making those claims in a witness statement verified by a statement of truth then proceedings for contempt of court is also a possibility.

Not a good strategy then.... much better to stick with facts.

So, the OP now needs to look very carefully at what their deeds say.

Jeepers_Creepers

Section62 said:

An awful lot of stuff. And why?

"Barrack-room lawyer"! That's funny

Sect62, have you seen the 'satellite' photo posted by AN? That shows that the default rainwater setup for that terrace IS for each pair of houses to have a single DP run along a near flat roof in order to get to a drain, and always the same house in each pair. Whether that's ideal from a 'technical perspective' is irrelevant - it's how it was done, and how it should be. It should not be altered on to another house without agreement.

Have you read about all the issues AN has had with this neighbour? Are they the type of person who would redo this DP is you asked them, even nicely? I don't think so.

Cool - I'm glad we agree on these two points. You do agree, don't you? I mean, you cannot possibly not agree with this? Good.

Yes, of course BC are ok with the DP - it does the job, and it is not for them to be involved in what is a civil issue. You set some store by BC's lack of interest for some reason, even tho' it's obvious why it ain't an issue for them, but you are not - surely - trying to suggest that AN should just accept the neighb's unilateral modifying of the default system for purely their own selfish reasons? (Oops, sorry, I'm assuming it's for their own selfish reasons). You aren't suggesting AN should just accept this, are you? Come on, now - you can't be! Good.

Grass, sedum, gravel, pea shingle, whatevs; you reckon - looking at AN's other photo - that the gravel & stuff isn't coming from this neighb's roof? Look again. See? Good.

You aren't suggesting that this is ok, are you? Cool.

Anything else? Oh yes, the B-R lawyer quip. If the neighb's alteration of the DP coupled with the debris coming from their poorly-maintained roof is causing issues for AN - especially after they've gone to the expense of recovering their roof - and if that neighb doesn't voluntarily sort it (happy to bet on this - and I'm not a betting man), AN should just suck it up? I don't think so, but it has to be AN's call. I've outlined the approach I understand should be taken - whilst making it clear that AN should determine that this is correct. If they have LP on their household insurance, then one call will determine (a) if they'll take it on, and (b) if they don't feel they should, they'll guide AN on what to do.

What's your recommendation - 'suck it up'? Surely not.

Sect62 - why?