Plaster on external wall blistering (damp?)

[JBM2015]

Hi all,

Got some really valuable advice last time I posted, hopefully I'll be as lucky this time!

I've just moved a table away from a wall in my kitchen and discovered what looks like blistering in the plaster on an external wall - see attached.

This is just my diagnosis based on a quick Google search, no professional has had a look. Suggestions seem to range from rising damp (can't say for sure if there's damp course but it hasn't done it anywhere else on the wall and we've lived here for 3+ years) to air bubbles under plaster (wall was bonded then skimmed). There's also a door on the other side of that wall and it's not completely out of the question that there's water getting in gap the frame - see other attached pics.

Any input greatly appreciated.

Thanks

 

[Doggit]

The green behind the soil pipe suggest there's a leak, so check that first. The walls been bonded, and then skimmed, so you need to check if the bonding goes right down to the floor, as bonding just sucks up water, so it needs to stop short of the floor. You need to fill the gaps by the door, to make sure that there's no rain getting in, and you need to dig out the white gravel, and put in larger stones, as that has got clogged up with dirt, and will be taking water across to the wall. Wehn you dig the gravel out, you can check to see where the DPC is, and see if it's been bridged.

 

[vinn]

Green algae is often as a result of splash from above rather than leaking pipes but not always.
Its easily corrected.

Anyhow, smeared on pointing is doing nothing for water tightness but as its a cavity wall then moisture should not cross the cavity. Unless the cavity is blocked and bridging the damp? Or cavity insulation is compromised and wet?

The hacked out plinth is showing signs of damp, and the old wall line indications above it point to a previous wall butting up. That wall was presumably cut open to allow the door with the external hinges - and what an mess has been made.

The threshold on the right is too low and appears to be decaying and possibly allowing moisture to capillary creep beneath it.
The threshold of the door on the left is one brick higher - I suspect that the external ground level is too high?

OP, can you point out where the DPC is?