I’ve been asked to protect a brand new patio for one of my customers i offered biocide treatment just wandering if anyone else does this I no sealing it would be best option but I don’t get involved in any sealing was thinking twice a year treatment what do you think?!
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Sandstone paving
- Thread starter tench0771
- Start date
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It depends what you mean by 'protect'? Biocide only relates to lichen/algae etc.
How is the patio going to be used? If they're going to have BBQ's, parties etc they may want protection from oils, grease, fats, spilt drinks and food or they may want to protect their investment against fading from sunlight/ In which case it needs sealing.
Clear finish sealers aren't a problem and it's the gloss/wet look types that can visibly degrade.
And if it's brand new you should allow ar least 3 months before treating with a sealer to allow for efflorescence to show. All being well it won't be an issue but you don't want to go sealing in efflorescence salts.
Sealers aren't a problem if applied to dry surfaces in dry weather and mild temperatures - and as per manufacturers instructions. They can be a decent earner if done properly and nothing to fear.
How is the patio going to be used? If they're going to have BBQ's, parties etc they may want protection from oils, grease, fats, spilt drinks and food or they may want to protect their investment against fading from sunlight/ In which case it needs sealing.
Clear finish sealers aren't a problem and it's the gloss/wet look types that can visibly degrade.
And if it's brand new you should allow ar least 3 months before treating with a sealer to allow for efflorescence to show. All being well it won't be an issue but you don't want to go sealing in efflorescence salts.
Sealers aren't a problem if applied to dry surfaces in dry weather and mild temperatures - and as per manufacturers instructions. They can be a decent earner if done properly and nothing to fear.
scottish cleaning service
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I would just Softwash it each year.
I do alot of sandstone, always hypo it and never had any problems with rust - but I understand your concerns.
And if it's just algae / lichen etc he's worried about then biocide has got to be the way forward and try and get it as a yearly maintenance job. Low pressure application with minimal amount of water should also avoid triggering any efflorescence that might be lurking.
And if it's just algae / lichen etc he's worried about then biocide has got to be the way forward and try and get it as a yearly maintenance job. Low pressure application with minimal amount of water should also avoid triggering any efflorescence that might be lurking.
Truckcab79
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You’re confusing hypo with brick acid. Hypo won’t bring out rust stains at all.
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Hypo will cause rust stains in natural stone and slate if there is iron oxide in them , it wont remove them but will cause or make them worse
who's confusing hypo with brick acid?
Truckcab79
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Where have you seen that? I lay patios for a living and clean them also. The vast majority of manufacturers / suppliers recommend sodium hypochlorite (or just regular bleach) to clean natural stone. I’ve never seen reference to it drawing out the naturally occurring iron oxide in sandstone nor have I seen it happen myself. Brick acid on the other hand is well known for it though if you’re sensible and flood it before and after then you’re unlikely to have a problem even with that. I’ve done it more times than I can count.
Can you post a link to the info.
Much appreciated.
Truckcab79
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The OP in the above post. Hypo doesn’t ‘rust’ stone. Brick acid can though.
Last edited:
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- 13,553
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Hypo will make any iron oxide in slate or any other stone look worse and will set the stain if it’s on tender , we softwash a lot of slate hung buildings and on the cheap slate I always warn the customer that it might bring out turn any iron oxide that initially looks a black colour red rust we have had this happen many times , we don’t use brick acid only hypo .
