Drainage old property on road

[Moshi]

Hi everyone, looking for some advice on a drainage issue on a 300yr old property that has a pavement and road built up against the front wall.

The pavement has been built up over the years so it is above the internal floor level. The cottages once had 2 steps going up to the front doors but now the pavement is flush with the door sills.

The pavement slopes back towards the house so all rain and road water runs back into a small gulley and soaks the front wall. The wall is a solid brick wall so moisture is transferred straight through the brick work.

We've managed to get the council out and they've agreed to come out and slope the pavement away from the house which will help but looking for advice on how best to detail the gulley between the house and pavement that we need to act as a French drain but as its a mid terrace we haven't got anywhere to drain to.

I've drawn a diagram to explain better but not sure how to get that on here from my phone!

Any suggestions very welcome

[Tony McC]

There should be a proper interceptor, such as a linear channel, between the public highway (which includes the footpoath) and your property.

It's up to the council to determine where to outfall. It might need a connection to a main sewer buried beneath the road. What they can't do is outfall onto your property or any of your neighbours.

This is a public highway matter and so none of it is your responsibility. You obviously have the right to ensure your property is protected and safe, but the design, installation and the cost is all down to the council.

[Moshi]

Hi Tony, thanks very much for your reply.
I spoke with the council guy yesterday about putting a drainage channel in front of all the terrace cottages but he was very reluctant as he said there were too many obstacles in the way, gas and water pipes etc.
Also the other issue would be that it would need to be set in concrete which would be up against our front wall, not ideal for the old lime mortar brickwork as it would trap moisture in the brickwork, and bridge any possible dpc, although it's unlikely there is a dpc given the age of the building.
Is there a way to upload any pictures from my phone as it might help show the situation a little more clearly?
Many thanks.

[seanandruby]

If they have agreed to slope the pavement away from the house then surely it must be up to them to either put in a linear channel, or let the surface water drain into the road ???

[Moshi]

Hi, I think I've found a way to attach some images, links below. BTW the lime render panel shown needs a top coat it's not just a rough job


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[Moshi]

Hi seanandruby,thanks for your reply.
The main issue is keeping water away from the wall and allowing it to travel away before too much of a build up as well as trying to maintain some kind of breathability in the wall so it can dry.
An architect I know said putting a French drain there may make the problem worse as water would just sit there with nowhere to go but down my foundations and any concrete up against the wall just holds in the moisture and degrades the bricks

[Moshi]

Forgot to add that we've had to raise the front door by 3 courses of bricks as water used to come down the pavement and over the threshold in heavy rain.

[Tony McC]

I can't see any reason why the open channel you currently have between house and pavement surface could not be 'lined' with a linear channel. It *has* to be a safer and better option than what you have at the moment, if only in terms of keeping litter out!

The fact that it has to be laid on and haunched with concrete is immaterial to your lime mortar bwk. There would (should!) be a membrane of PIFA or similar between wall and concrete to act as a slip membrane and there's a good case to be made for using a waffle board to aid ventilation.

As for the problem with underground services: tough! The fact that there are underground services in the path is *never* an acceptable reason not to install adequate drainage to protect a private property. It is the responsibility of the council to find a suitable route for outfall drainage or, in the most extreme case, arrange for re-routing of the services to allow drainage to be properly installed.

"It's awkward" is never a valid excuse.

[Dave_L]

It's a shame that Aco channel outfalling to the carriageway isn't at the lower end of your property as then the job would be easy. For the cost of it I'd put the channels in myself if this were the case.