Help with damp patch please

[Blueshededwardian]

Hello, another "help my wall is damp" post

Attempts at repainting visible but I'm not sure how to go about fixing this issue for good. The wall is the gable end of a semi and the damp patch lines up with where the gutter drain is. I'm unsure if the issue is related to the downpipe itself, the drain, the ground level or the pointing (or all of the above!).
Had a builder suggest I needed a new DPM which I politely declined having spent some time already on these forums. Very grateful for any advice.

 

[housewinnie]

I would start with repointing and possible fill in the air bricks. Also cut a hole in the drain grille and add a piece and run the down pipe into it.

 

[Lacan07]

All of the above, that wall desperately needs some TLC. Move the air bricks further along the wall if you can, and grab yourself a brolly to check that guttering when it's raining.

 

[Blueshededwardian]

Much appreciated replies, thank you. I have started to dig by hand to investigate the concrete depth prior to hiring/renting an angle grinder to make the task of digging a channel drain easier. I have gone down about 2 bricks depth before the bricks start to jut out (the third course below current ground level) which I think is the start of the foundations? How far down does my channel drain need to be?

 

[paulc]

I'm a big fan of the Floplast debris interceptor - If you don't mind breaking concrete and moving a bit of the underground drainage, it would cut any splash back to zero.

 

[Blueshededwardian]

I'm a big fan of the Floplast debris interceptor - If you don't mind breaking concrete and moving a bit of the underground drainage, it would cut any splash back to zero.

Thank you that looks much better than the current setup. I'm planning to have an approx. 6inch wide trench the whole length of the wall which I'm going to fill with pea gravel so I'm digging up concrete anyway. There is a terracotta drain that connects to the existing gully on the right hand side. Would you suggest replacing the existing gully entirely and connecting the new gully to a new p-trap and then the terracotta drain or could I reuse the existing gully somehow? Do you have any view on the air bricks behind?

 

[paulc]

I'd rip out the current gully and expose as much of the original clay pipe as needed. Fit the debris interceptor along with a P trap. Using as few bends as possible, connect to the old clay pipe, job done.
Rather than going to the effort of moving the air bricks, relocating the downpipe say 6" one way or other would probably be less effort. It is just a modern bit of plastic, so no real heritage there to conserve (might have been different if it were Victorian cast iron).

 

[Blueshededwardian]

Another update, I chickened out of replacing the existing plastic gully as I was worried about disturbing the clay drain it's attached to. Instead I'm planning to cut a hole in the grate, extend the guttering directly into the gully and fix some additional clips to stop the downpipe moving around and missing the gully/sending water hurtling through the airbrick.

I've started on lowering the ground level, not as low as I'd like due to the clay pipe but at least 1 brick course below the air brick level and I've then topped with 20mm gravel. I've also made a start on the repointing (in cement... I know I know). I'm a fairly competent interiors DIY-er but anything exterior is new to me so any tips or comments welcome!

I picked up my new angle grinder yesterday ahead of a weekend of ground-lowering down the rest of the wall. The wobbly line of this section was partly due to my somewhat haphazard chizeling but also the terrible quality of concrete path. There are about 4 different types of concrete along the 7m path, I hope my grinder is up the task!