Patio and dpc...

[zzr-matt]

It seems like the previous occupants had one end of the patio laid above the DPC in a couple of places...



Our houses are on a hill and are staggered so the wall you can see on the right there is my wall and the one at the top of the pic is my neighbours. On my wall the DPC is 6 or so bricks up from patio level and maintains this height for around a brick or so's length around the corner onto my neighbours wall.

Their DPC is 3 bricks Below patio level on the left of the picture above. They mentioned that they were getting damp in the corner of the room that backs onto here which started just after the previous owners of my house had the patio done right up to that corner wall.

The patio also seems to fall into that corner so thats where all the water goes! I decided to break it out and this is what I found...



Lots of sand stoney style bricks ontop of engineering bricks. I then got the hammer out and removed this to leave me with this:



The earth is now approx 1 brick below the lowest point of the DPC. One day on and the bricks that were below patio level are still drenched but starting to dry out.

I've had a look at DPC page on the main site and there seem to be a number of options some of which may leave me a ditch/gully at the side of the patio about a foot deep. I'm just unsure of which is the best solution and whether I need to add drainage or just rip the whole lot out and start again

Just after some general advice on what the pro's would do if they had been asked to sort this out!

Cheers

Matt

[Dave_L]

Would ideally like to see a 'bigger picture' of the whole area in question to give me an idea, but a reduce level dig-off job looks favourite......

[zzr-matt]

Thanks for the speedy reply Dave. Here are some wider view pictures. I know its a bit of a shat patio with rocky slabs etc but it is on the list to sort out at some point. Sorry I can't move the furniture thats in the way, its all a bit wet and heavy at the moment!

Down the hill with the excavation in the top right of the photo:


Excavation on the left of the photo and clearly showing the fall to that corner:


The end of the hole and some of the stuff I had to dig out:

[Dave_L]

I don't see any other answer than to dig off to a formation level that will give you a finished level circa 150mm below DPC - this will probably involve the construction of some step(s) to your sliding doors by the looks of it?

[zzr-matt]

Thanks Dave. Currently when you come out of the patio doors there is an 8x8 slab area a nominal 150mm down from my DPC level. This then drops 225mm onto the lower 8x8 area which can be seen above. Looks like I need to plan it out for a further 375mm of drop over a couple of steps then

What sort of step height do people normally go for? Is 225 about the norm or a little on the high side?

[Suggers]

It's amazing how quickly a building dries out when you reduce the outside ground level - just done exactly that, to a 100yr old brick&flint cottage - you could almost hear her sigh with relief !!
I'm with Dave...
Tony has excellent page on steps etc, and getting round the "2 courses below damp" on the main site.
(have done it to the mother-in-laws house - it works! )
(another 10 yrs will be the proof in the pudding)

[zzr-matt]

Well seeing as its been a couple of years since I started this I figured its time to stop being side tracked by kitchens and bathrooms and get this finished.

I've dug out the hole a bit more and it now looks like the pic below. I was going to go for a 200mm gap to the wall on the left then have a 600x600mm slab vertically placed as a retaining structure. Then some kind of raised bed before another retaining structure, a linear drain and the existing patio.

Does that sound ok? or has anyone else got any better ideas?