Should I lower trench or leave

Sekekama

1935 semi-detached Yorkshire. I had raised ground levels and obstructed air bricks which caused damp (image 4). 

Created a trench but I now found an old brick below new one (image 2) I dug down to get all air bricks to at least ground level. I've removed big stones to just have soil. 

There's 2 drainage gulleys for my house along this trench which I had found voids underneath but I filled with spare soil. I hosed water into the trench and eventually water soaks into ground but it does collect just below the old air bricks for awhile (image 1/2).

I've tried to remove as much of the concrete as possible off the face of the now exposed bricks (I will continue doing this before filling trench with pea gravel). 

Before winter I'm considering sealing the old air bricks (image 2) and half of the other one (image 1) in case of winter heavy rain because surely there's enough ventilation now? 

When I dug down deeper I just found clay soils and bricks and voids near the drainage gully, so I got worried as last thing want to do is disturb foundations. The inner subfloor is roughly 20 inches deep.

Also some of the air bricks are above DPC and some level/below. 

koalakoala

Was this not answered already?

user1977

There was a previous thread but the OP deleted the first post in it for some reason:

https://forums.moneysavingexpert.com/discussion/6601225

OP, it's easier for everyone if you just keep to one thread.