Soakaway-porch

[Surftuzzer]

Hi

Is there a building regs threshold for new roof square meterage that determines whether or not a soakaway must be installed?

We’re building a small porch. 2.3 sqm footprint. Water run off is not a lot for such a small roof.

The house is 2.2m above the lane (and 9m from it), with a sloped front garden.
Soil is 18” of topsoil then clay/chalk mix.

I’m not worried about water run off at all - there will be a flower bed under the front window where the downpipe will let out the water.

My issue is partly trying to keep it sensible on project costs and also that the soakaway location will annoyingly involve lifting a slab or tunnelling under our front path to run the pipe to the soakaway.

So I’ll only install a soakaway if regs require me too. Otherwise I will play it by ear or use a French drain perhaps to disperse water a little further away. Can install soakaway later if we feel the need.

Posting on here since the council building control guy has not replied to emails or returned my message for a week so I thought I might get a steer on here before i corner him over this when he visits next to see the roof.

 

[^woody^]

Does the porch need b building regulations approval? If it does, you'll probably need a method of dealing with any localised concentration of roof run off

 

[Surftuzzer]

It does required regs approval (insulated, new front door…).

 

[^woody^]

insulated, new front door

I'm not sure that's a reason

 

[wessex101]

I've got it in my head that any roof under 6m² does not require any rainwater gutters etc. for Building Regulations but I cannot remember the actual clause and I don't have time to look for it. If I get any spare time later I might see if I can find it.
If you look at Approved Document H page 40 Table 2 Gutter Sizes etc. there are no figures for roof under 6m² which would seem to tie in with my memory.

 

[^woody^]

What the OP to do? Have rain just flying off the roof, onto people using the front door and down the walls and splashing back up the walls creating a green algae and muddy mess?

The issue is more to do with water affecting the foundations and dealing with that.

Any roof can do away with gutters, irrespective of size as long as a suitable alternative is used

 

[wessex101]

The OP simply asked if Building Regulations required a soakaway for his porch. I offered the advice that to the best of my knowledge Building Regulations do not even require gutters on a small roof let alone a soakaway.
Whether or not a soakaway or guttering is desirable is a completely different issue that is up to the OP's discretion. If the roof eaves is adequate it is perfectly acceptable to do away with guttering. Most thatched cottages do not have gutters and they do not end up with green algae on the walls or subsidence. Plus the amount of rainwater running off a 2.3m² roof will be negligible.

 

[freddiemercurystwin]

Besides, the rain landing where there is no porch atm is currently just falling on to the ground in front of the house.

 

[^woody^]

Maybe, through no fault of his own, the OP is asking the wrong question? Which does not necessarily mean he should get the wrong answer!

 

[Surftuzzer]

I just chatted with the building control person on the last visit (checking roof structure), and we sized up the water run off requirement together. Naturally they do not give advice but they did describe the following:
For regs sake, they suggested the small roof did not warrant a soakaway, but it remained an option (albeit over kill).
Nor was it realistic to take water run off to existing drainage, due to location.
Nor are water butts something they like to approve as a solution.
So the main focus became the soil type, and shape, of the front garden we’ll be dispersing water on to. At which point it was pointed out that even if decided to put in a soakaway just to put pay to all this, regs approval would probably not be given cos there is no place I can dig it in that would be 5m, from either the house or the road.
They were of the mind that as we have a front garden up a bank 2m above the road with flower beds all about, it was almost certainly ok to simply disperse the run off into those beds and except the garden to cope fine. However, they told be categorically that they can’t tell me what to do and I should refer to document H (section 3) and discuss with my contractor.
The gist was, do something sensible and we’ll approve it, but we won’t tell you what sensible is or what the roof size requires.
Doc H does seem to detail everything you need for 6m2 roofs and up, but gives no info at all to hang my hat on, for a small porch roof.
I think we have choices… and I won’t pay for a soakaway they might actually object to. Therefore I will take sensible measures to lead water away from the drain pipes into the flower beds and see if they approve it. This perhaps, with some perforations along the tube for dispersal.
https://www.amazon.co.uk/DKIEI-Down...hvtargid=pla-2281435177578&psc=1&gad_source=1

If they don’t approve that, we’ll ask why and work it what we should do, based on their reply and science that backs that up.

Bloody crap. No idea why there isn’t a rule of thumb approach outlined for small roofs.

Re whether I need building control sign off… I do, due to the new front door in new position on front of our porch.

 

[Old Salt]

BC wont give advice in case it doesnt work or is not suitable for your situation. Thats why Doc H gives detail but every situation is different. I am over 5 metres from a road and could install a soakaway with no bother but we are on clay and realistically it dont work. So each case has to be judged on its merits.

Go with the perforated pipe and disperse any rainwater across the front. I have perforated pipe around my garage to try to improve the drainage which seems to be working.

 

[Surftuzzer]

Thank you. Makes sense to me.

what perforated pipe did you use? Be good to know as it’s proving itself.

 

[Scally-Ho]

That DKIE drain kit seems a sensible solution to me and for a sensible price too A mini soakaway with minimum invasion; what's not to like

 

[Old Salt]

Thank you. Makes sense to me.

what perforated pipe did you use? Be good to know as it’s proving itself.

Got it from these guys

http://drainageonline.co.uk

 

[freddiemercurystwin]

What you need to do is tell (email) your inspector with details of your proposal and ask if he will approve it or not.