efforvesence

[JoeyB]

Why have I got white salt deposits showing in the cement between brickwork.
This has never happened before.It is in various spots .I cannot get rid off it.

[pingping]

i heard from a bricklayer the other day that this is naturally occurring fluoresence in the bricks (minerals) that begin to show over the years following exposure with the elements.

Although I'm sure buildersmate on AB may well correct me on this!!

[jackthehat]

Effluorescence - the leeching out of the mineral salts in new brickwork/mortar by rainwater (mainly). This will disappear in time.

[gen2]

Effervescence is fizzing and bubbling

Fluorescence is the emission of longer wave radiation when stimulated by radiation of a shorter length.

The correct term you are looking for here is efflorescence

You will find lots about it if you Google for
cement brickwork efflorescence

[buildersmate]

It is what Pingpong says - soluble salts in the building materials coming to the surface with the moisture in the bricks, then crystallising. That's why you generally see it on damp parts of the structure - chimney stacks. You may be able to get rid of it by brushing it gently, and over time (couple of years) it will cease to come to the surface. Washing with water won't help.

[terence7556]

i read that using a scrubbing brush each time it appeared eventually gets rid of it with some good old fashioned elbow grease. a scrubbing brush is about 8-10 inches long