1930 house, shallow foundations, driveway over DPC

[ctx2]

Hi

I bought a 1930 house last year. The driveway down the side of the house was just below the DPC and at the back corner it was just over. Causing rain to splash over the DPC. After looking at multiple threads of similar problems the solution is dig the drive down and replace so it finishes 150mm below DPC. Simple right?

So i started to dig down around the house to stop the rain splashing over the DPC and see what i am working with and this is where the problems start. The house is built on boulder clay & it looks like the foundations at the back corner and side are less than 150mm from the DPC! I was expecting it to go down 4 - 7 bricks from the drive level before the foundations. 1930 house building for you.

I was originally planning to replace with block paving or gravel in plastic grids. Problem is i will have to dig down at the side and expose the shallow foundations so i can back fill with type 1 then either blocks or gravel. This will have the drive finish at foundation level, but the foundations should be buried right? If you look on the picture of the back of the house the concrete slab is the same height as the buried foundations. So is this already exposed foundations? i put arrows on the first picture where the foundations are.

No matter how i look at it either the drive finishes close to foundation height if i dig down or if i cover the foundations with 150mm sub base, sand & blocks will be higher than it is now covering more of the DPC and will be above the doors!

Im looking for some advice & ideas on how to replace the driveway without causing any problems with the foundations.

could digging next to foundations cause problems with them moving?
fill next to house with concrete and put a slope into an aco drain?
put aco drain next to house, that will be as high or higher then the DPC?
use mot type 3 & gravel so it drains and wont splash, but clay drains slowly. Possible problems with water under or around foundations?
finish the drive at dpc level and seal or cover the bricks to avoid bridging?


Any help or suggestions would be appreciated!

 

[^woody^]

Im looking for some advice & ideas on how to replace the driveway without causing any problems with the foundations

You wont.

A top of a foundation is nothing really.

 

[ctx2]

You wont.

A top of a foundation is nothing really.

The foundations depth are only about 75 - 100mm i think (1 brick thick).

So when i dig down next to them by 250mm i will be exposing all the foundation. Could this not disturb them or cause problems?

Anyone have any suggestions about the driveway?

 

[^woody^]

You're saying that that house is resting on foundations that are just 250mm deep below the surface?

 

[ctx2]

You're saying that that house is resting on foundations that are just 250mm deep below the surface?

I dont think they were even 150mm from the old drive surface i removed. They are 1 brick under the DPC at the back corner of the house. Look at picture 3. I started breaking it up thinking it was the old path underneath the tarmac only find clay underneath the concrete and no more bricks

The 250mm i mentioned was how much i need to dig down next to the foundations to back fill with 150mm type 1 + sand and blocks on top for new drive

There has been no movement in the house so far. No cracks in any external brickwork or mortar etc. Other house the same as mine have 2 steps up to the back doors. I only have the 1. Makes me wonder if its more solid boulder clay under my house?

*edit

forgot to add the foundations are deeper at the front only by 2 more brick courses tho. I assume they are all 75 - 100mm thick foundations only checked the back corner