Drains, paving and damp - Drivway is diverting water into subfloor

[ashstuff]

Hi,

I have a drainage issue which is causing damp within my home,

Please have a look at the pics, its been raining today and you can see water forming puddles around the building. You can also see water which is channeled around the bay window (as it is on a slope) but as it goes passed the cut off airbricks it drains through onto the subfloor. As you can see we have a puddle under the floor today after a couple of hours rain.
Two air bricks on this side of the building either side of the bay window. These are two brick's deep and what looks like an original doc is level with the top of the air bricks. Pointing has mostly gone at ground level.

I'm thinking of removing the last course of bricks on the driveway and installing a concrete channel (so ground level would be 2 air bricks below the dpc where it meet's the houses) which would drain into existing drains. I woudl repoint the brick work as well, my questions are:

1) Am I on the right track?

2) How am far should I dig down and backfill with concrete?

3) I think the house is lime mortar (1929), should I repoint in lime? If I'm pouring concrete do I need to repoint below the level of the concrete? If so how long should I wait for the pointing to dry before installing the concrete?

[seanandruby]

It looks like the whole lot needs repointing and maybe some waterproofing. if it is all falling away from the house you shouldn't need a linear drain. You might need a box out arrangement around the air vents if blockwork is to high.

[ashstuff]

Thanks, few people have suggested repoint and sorting out the airbricks, I'm coming around to this idea as it'll maintain the look of the driveway (I can always add in a drain later if needed). What do I repoint with? I believe lime is best as its softer and moves with the old softer bricks but presumable this isn't very waterproof? Is there a more modern solution giving waterproofing and flexibility?

[Tony McC]

I'd have a look at moving that soldier course away from the brickwork of the house, say 200-300mm, and re-seat them on a concrete bed and haunch. Then, dig down to at least 100mm blow the base of the airbrick, and fill the resulting gap with gravel.

I know I have a deep and overbearing aversion to so-called 'splash strips', but I think it could work in this situation because it's NOT acting as a drain/sump for surface water from the driveway, just a way of keeping that airbrick above the potential water level.

As for the re-pointing: always re-point lime mortars with lime mortar. Cement over lime = problems

[ashstuff]

Thanks Tony, what's a haunch? Is this a 'lip' on the edge of the brickwork to prevent water running into the gap?

[Tony McC]

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