White powder on Victorian basement lights

[iantresman]

We had some lights fitted to the basement interior walls a couple of years back.

I recently noticed a white fluffy deposit accumulating on the emergency lights beneath the main lights, which peaks at about an inch high. It looks salt-like, rather than fungal.

Any suggestions?

Regards,
Ian Tresman

 

[RigidRaider]

Sounds like efflorescence, ie salts coming out of the wall. Is the wall damp?

 

[JohnD]

If it's in a pile, could it be below where holes were drilled in the wall, e.g. to fix the lamps or cables?

 

[RigidRaider]

Does it taste salty?