White patches on sandstone patio slabs

[taterska]

Hi there, I've sealed my patio last night and later this afternoon white patches appeared on some of the stone slabs, please, could some one help how I can fix the problem:-(here is a picture of one of the ruined slabs


Any thoughts are very appreciated please...

Thanks!

 

[One Day]

Hi, We need some more info before we can advise:
Stone sealed with what?
Was the stone damp before sealing?
How long has the stone been laid?
What is it laid on?

Answers please and we'll try to help!

 

[taterska]

Hi,

it was laid last Wednesday, so a week ago, I sealed it with Wickes sealer while waiting for my other sealer to arrive, that is supposed to give the wet look finish.

The stone looked dry, I washed it 2 days ago before the sealing and the weather is extremely warm, it did look dry to me.

The guy that did it put a protective sheet on the ground and then there is a concrete foundation and then the stone. Hope that helps to give you full picture but please if you need any furhter details, I'll do my best.


Thanks a lot!

 

[J Sid]

Had a whole floor go like that. 80m2, scared the **** out of me. Stone had been down a week before sealing with stain stop and was dry before laying.
For me it wash off fine. Left it to dry again then resealed.
If you give a good wash you should be fine.

 

[widler]

Were they laid on sand and cement?
Looks like effluence (salts out the sand )

 

[peterwhayward]

Were they laid on sand and cement?
Looks like effluence (salts out the sand )

Sorry but that's funny.........I think you mean efflorescence (what you have put is sewerage)

 

[widler]

Ha ha at 1st i put 'salts' then tried to spell efflorescence and it cam out as the one above, bloody spell check, and it was 6 oclock

Ps now im awake i can read it now , doh

 

[taterska]

Thank you all for the input, so glad I found this forum!

Julian, the patio is sealed once, will it still wash off in that case, i was supposed to apply to coats but after the first all these patches appeared and i haven't done the second coat yet.

DO i have to remove the sealing coat? If so how can i do that?

widler, it is on cement and sand.

Thanks for all your help!

 

[Andy Allen]

Allways new you were full of effuence. .:sofahide: lol

 

[widler]

Well apart from the poo i spoke, its efflorescence imo,

 

[J Sid]

Should just wash off. Let it dry completely and give second coat.

 

[taterska]

thanks!

I'll do that.