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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Building Questions >> White powder (effluorescence?) on walls https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1492886269 Message started by Zac on Apr 22^nd, 2017, 7:37pm

Title: White powder (effluorescence?) on walls
Post by Zac on Apr 22^nd, 2017, 7:37pm

About 5 weeks ago I had my kitchen reskimmed but I haven't redecorated yet. Near the kitchen sink, behind the washing machine, a couple of patches of powdery white deposits (effluorescence?) have appeared, also a patch near the kitchen door (both patches on outside walls). I'm now wondering if I need to repoint the brickwork outside to stop dampness. There are also effluorescence remover products on the market but I feel that they would not really solve the problem. Any advice welcome.

Title: Re: White powder (effluorescence?) on walls
Post by woodsmith on Apr 23^rd, 2017, 8:04am

How old is the house, and do you know how the walls are constructed?

Title: Re: White powder (effluorescence?) on walls
Post by Zac on Apr 24^th, 2017, 12:31am

1920s/30s. Double brick, no cavity wall.

Title: Re: White powder (effluorescence?) on walls
Post by woodsmith on Apr 24^th, 2017, 10:28pm

Sounds like you do need to check your pointing and look for any signs of water getting onto the brickwork from faulty guttering for instance. However it may just be salts in the brickwork,or mortar, that have been activated by the wet plaster and once you clear them off they won't reappear.

Title: Re: White powder (effluorescence?) on walls
Post by thescruff on Apr 25^th, 2017, 8:47am

woodsmith wrote on Apr 24^th, 2017, 10:28pm:

However it may just be salts in the brickwork,or mortar, that have been activated by the wet plaster and once you clear them off they won't reappear.

That's what it sounds like to me, you can tell if the plaster is dry/drying as it changes colour (lighter)