Drainage Along Side of House

Soldato
Joined
7 Apr 2004
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Hi,

One side of my house has (stupidly) had the driveway built up to be level with two airbricks. I've only recently moved in but given the past couple of days rain there's 100% water getting in the airbricks. Downstairs floors are suspended/tiled so I can't see how bad things are under them but there's no signs of any damp. Interestingly one airbrick looks full of internal cavity wall beads - so maybe it doesn't drain straight through to floor space.

I do want to get this fixed though before it causes a problem, would the following be sensible?

* Remove 15-20cm of bricks from the wall
* fit a french drain along the trench
* connect to guttering down pipe at the far end
* cover with very small gravel/shingle

If that sounds sensible, who would I speak to for this kind of thing? A Builder or landscape gardener maybe? It's only few meters long so hopefully not a huge job but no idea who to approach.

This is what it looks like - the wood is just a failed attempt to cover during rain :(

 
Associate
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Stafford
yeah dig it out just below the air bricks and stick one of these in.

https://www.aco.co.uk/complete-the-look

Look at the rain drain ones.

Dont cover the air bricks, you might be able to find one with a lip on it that lips over the edge of patio and takes all the water off the patio.

But saying all this you might find that its not actually causing you any issues and that its finding its way out already but I would want to check.
 
Soldato
OP
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Thanks, that looks ideal. I think i'd be ok fitting those but would struggle connecting the end to the existing guttering down pipe system. Is that likely a difficult job? I guess those have to be installed at a slight slope as well? Maybe I should try a MyBuilder handyman search for this kind of thing...
 
Soldato
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Can you see your DPC? I can't really tell in that photo.

But a dpc should be 150mm above surface and ideally an air brick at least 75mm. Some helpful info:

http://www.nhbc.co.uk/Builders/Prod...uidanceDocuments/61/filedownload,65368,en.pdf

That, and you need to check round all your air bricks to make sure they're clear, if they're blocked with cavity wall insulation you'll need to get them cleared out to prevent damp issues with your floorboards and joists.
 
Soldato
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Thanks, yes the airbricks are just under the DPC but the problem is they are at the driveway level as it's been built up at some point. So digging out a small channel with a drain seems like the way to go, to at least add some more height from surface level.

Does the fact they have cavity insulation in them suggest they vent to the cavity rather than straight through to the void - meaning they only vent the cavity rather than suspended floors? I'm not sure how else it could have got in. The air bricks have a protective mesh on the front, so the insulation must have got in directly from the cavity when installed.
 
Soldato
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If it's only a couple of airbricks, can you get some kind of snorkel fitted to them?
There are various angles of plastic ducting available in various dimensions, though I couldn't tell you which industry is most likely to have such stuff, but that may be a lot cheaper than rebuilding things...
Might even be able to get custom rectangular elbows made up. Seal it on, grille over the open end and, long as it's above the driveway level, you're sorted.
 
Soldato
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Thanks, yes the airbricks are just under the DPC but the problem is they are at the driveway level as it's been built up at some point. So digging out a small channel with a drain seems like the way to go, to at least add some more height from surface level.

Does the fact they have cavity insulation in them suggest they vent to the cavity rather than straight through to the void - meaning they only vent the cavity rather than suspended floors? I'm not sure how else it could have got in. The air bricks have a protective mesh on the front, so the insulation must have got in directly from the cavity when installed.

the air brick needs to go all the way through to the void under your suspended floor.

When your cavity wall insulation was done the installers should have removed the airbricks fitted a sleeve to prevent the insulation blocking it all up and then reinstalled the airbricks. Sadly this rarely gets done.
 
Soldato
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the air brick needs to go all the way through to the void under your suspended floor.

When your cavity wall insulation was done the installers should have removed the airbricks fitted a sleeve to prevent the insulation blocking it all up and then reinstalled the airbricks. Sadly this rarely gets done.

Makes sense, I imagine that's an expensive thing to fix once it's been cavity filled :( Maybe i'll just fix the drainage and pretend it's all fine...
 
Soldato
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Makes sense, I imagine that's an expensive thing to fix once it's been cavity filled :( Maybe i'll just fix the drainage and pretend it's all fine...

No not really, for most houses you should be able to shine a torch through the airbricks and see the joists and floor boards. if all you can see is cavity insulation then you can either pull up a couple of floorboards and clear them out from the inside or from the outside remove the airbrick and scoop out the insulation then cement the airbrick back in place. the insulation shouldn't drop back down out of the cavity as it sticks to itself.

Don't ignore it though as you could end up with rotten joists and floorboards overtime, not cheap or easy to sort out.
 
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