Brickwork below/around slate DPC damaged/damp!

[Helpmediy101]

As i mentioned above, from the pics you have a cavity wall, and unless the cavity is blocked and bridging from the outer skin to the inner skin, then any moisture getting into the outer skin cant cross the cavity - so no French type drains are needed.

The slate DPC we can see in the outer skin is maybe working in the outer skin.
But we dont know whats happening with any DPC in the inner skin?
In fact, your new pics show obvious damp conditions in the inner skin - it could be rising damp or penetrating damp or both.
No pics so i dont know whats happening in the bay?

What do you mean by redone render - maybe all the render on the lean-to needs knocking off.
I cant see to much of the house render.

Thanks I won't worry about the French drain then. There isn't any obvious signs of damp in the house other than those pictures I sent - no musty smells, peeling/flaking paint anywhere else at all. The bay is also completely fine, it is just around this extension where we have the issue, which looks to be just caused from the bricks being damaged by rain. Again it's just this back of the house render that is dark - the front is absolutely fine.

I suppose then it's a case of: fixing the guttering above the extension/lean-to, repointing those damaged bricks, replace at least a few of those bricks at the base and possibly look to re-render the whole back?

What are same tail tail signs of a more serious issue?

 

[JohnD]

The mortar is eroded beneath the DPC

This is typical of lime mortar where there has been a long term leak, typically from a broken salt-glazed clay gulley, or a soil pipe. The verdant plants are a bad sign.

When you dig out the broken drain, expose the brickwork below ground, hose out the mud from the joints and repack with cement mortar. Chip out the previous shoddy attempts so you can do a good depth of fill and hopefully a neater job. The damage will extend below ground level.

 

[Helpmediy101]

The mortar is eroded beneath the DPC

This is typical of lime mortar where there has been a long term leak, typically from a broken salt-glazed clay gulley, or a soil pipe. The verdant plants are a bad sign.

When you dig out the broken drain, expose the brickwork below ground, hose out the mud from the joints and repack with cement mortar. Chip out the previous shoddy attempts so you can do a good depth of fill and hopefully a neater job. The damage will extend below ground level.

Thanks for this - going to book a drainage survey and see what it is. Today noticed the interior wall on the other side of the damaged bricks/render is getting damp after the rain/snow. Think the render needs to be stripped back and investigated now too.