White powder coming up from ceramic tile flooring...........

[Claude]

......leading onto the back patio doors, which lead onto patio. Please can anyone tell me what this is. Scared that it's rising damp, but property is 1.5 year old and in Cyprus so not much wet weather out here. Noticed it when drawing curtens that the powder gets onto patio edging. Maybe bit of this is outside on patio also where the grouting seems to be whiter in areas. Any ideas anyone?

 

[kendor]

Drawing curtains, white powder! sounds like a job for the drug squad!!

 

[Richardp]

sounds to me like you got concrete made with sea sand and the white powder is Efflorescence.
it'll keep coming, just brush it away.
you could try a brick cleaning acid.

 

[sandwell]

We had the same problem with some quarry tiles a few years ago.
An old builder gave me a tip which worked. Wash it over with vinegar.

 

[Claude]

Ok thanks. Will try it. Just noticed that on the side of the patio it is a bit wet and there is some white fluff on it. Is this a form of damp and if so what can I do about it? It has been a bit wet recently and now we are due 8 months dry weather, does this matter?

 

[JohnD]

Any dissolved salts will tend to come out when they dry out after getting damp. If it's flufffy you may be able to keep it under control with a broom, but it can form very hard crystal deposits that vinegar or brick cleaner will take away, as Richardp and Sandwell say.

Try not to wash with water too often or it will be damp and keep happening.