Patio/drive problem? dpc and foundations. - How to cope with dpc close to foundation

[James Latimer]

I've dug out to lay a gravel drive/"patio". The ground level *was* level with/above DPC. The house DPC is very near the foundation, that is one brick above where the bottom of the wall is "stepped out" above whatever foundation is there (probably not much!). I could supply a link to pictures if that would be useful; attempted ASCII art (section):

#####
House
wall
##### ^up
#####
===== <- Slate DPC
#####
###### <- Stepping out
####### <-Dug out to here
#######

The subsoil is hard sandy clay with flat shards of sandstone in.

I have been considering what to do where the drive/patio will meet the house, allowing for drainage. A possible solution occurrs: would it be OK to put down a compacted sub-base of Type 1, using the house wall as edging, to a level 1 brick below DPC, finishing with a decorative gravel hiding the "stepped out" part of the wall?

This would give huge advantages over impermeable surfaces (water could drain straight through, so remove need for bespoke drainage, reduce work by eliminating need for parallel (to wall) edging).

The patio would take only foot traffic - the driveway an ordinary car.

Any helpful advice will be very welcome.

[lutonlagerlout]

will the patio fall away from the house?
as i understand it the reason for 150mm is that that is how high rain can bounce,maybe if you chopped the concrete back to the brick that sticks out you could use a linear drain tight to the brick,make a bit of a feature of it?

TBH the patio in my house (similar wall detail ) was level with damp and there wasnt a spot of damp in the house,so when i redid it i dropped it to 100mm below dpc and sloped it away at 1:60,and so far there have been no issues

although what you are suggesting is not to the letter of the law it will be an improvement on whats there
LLL

[James Latimer]

> will the patio fall away from the house?

No. I was thinking of making it flat and level. Rainwater should drain through, shouldn't it? The subsoil is rather permeable, and not all squidgy. I raked some pea gravel over it for temporary decorative effect. Currently a downpipe discharges straight onto the top of the dug-out area (it was dug out a year or three ago) and there's only pooling for 2 minutes if the rain is very heavy.

[img=http://img403.imageshack.us/img403/8376/bild1506sd.th.jpg]

gives the general idea. The weeds would be dealt with, of course!


> maybe if you chopped the concrete back to the brick
> that sticks out you could use a linear drain tight to the
> brick,make a bit of a feature of it?

I don't really want to put a drain in. There are difficulties in design and directing the outfall (as well as work and expense)!

[Stuarty]

Theres your pic for you

You dont want a patio or a drive perfectly level, it needs to have a run for the water to shed off. If you dont want a linear drain running along the edge of the house, why not have the block / slabs stop short of running tight to the brickwork and have something like 150mm gap with a shallow land drain running to a suitabley sited soakaway covered over with decorative agg?

To be honest i dont know if your post is confusing me or the grey matter just isnt quite working as it should today :/

[James Latimer]

You dont want a patio or a drive perfectly level, it needs to have a run for the water to shed off. If you dont want a linear drain running along the edge of the house, why not have the block / slabs stop short of running tight to the brickwork and have something like 150mm gap with a shallow land drain running to a suitabley sited soakaway covered over with decorative agg?

The idea was to dispense with the need for a drain around the house. One could, I suppose, be put in, but it would be a lot of work, and there's nowgehere for it to drain to - indeed, as I'm considering a permeable construction of decorative gravel on top of compacted Type 1, is there a need for a drain, or any need for a slope? The sides of the drive/patio would have to have some sort of edging, probably brickwork, or "slab on edge".