Internal brick work growing white fur - WHY?

[lostinfens]

I stand corrected
But do you fill them in sub-dpc??- Anyhow it might have been one of those damn Northeners who slipped through the net.
(I'm not actually from Lincs by the way-count my fingers)

 

[Chukka63]

You`re assuming the cavity is blocked... we don`t block cavities in Sussex

im not assuming the cavity is blocked.im assuming the damp is rising fromt he ground in the wall thats affected itself.

 

[lostinfens]

Its almost certainly coming from both the lower brickwork & probably transmitting from the external ground which appears higher than internally.
As for blocked cavity, it's normal to backfill to within 6" sub dpc, so that brings it close to ffl.