White deposits behind radiator

edchalk

Hi - we've recently moved into a new flat and after stripping the walls, painting, and laying new carpets we've noticed chalky deposits forming under some of the radiators (see picture).

Today I looked behind one of the radiators and it looks like some sort of horror movie - a weird mass of chalky stuff oozing out of the walls (see 2nd pic).

 Does anybody know what this is ? Should we be worried??
Thanks
Ed

neilmcl

Looks like a poor attempt at filling a crack to me. Difficult to tell for sure what it is unless you remove the radiator. If it's nothing to do with anything behind the rad then it could be some filler or cornice adhesive from higher up that's dropped down behind the radiator and forgotten about.

Mistral001

Try putting a little on your finger and tasting it.  If it tastes salty then it is likely due to dampness in the wall.

societys_child

As above ^ . Sounds like salts coming to the surface as the wall dries out. Have you previously noticed any damp?

troffasky

"salts coming to the surface"? It looks like it's oozing out of the crack in the wall!