Indian sandstone patio stains/marks

[James McFadyen]

Hi all,

I had an Indian Sandstone patio laid last year. Everything looked fine to start - we left it around 4 weeks and then sealed it whilst there was good weather.

After sealing it, we saw that many of the slabs had these strange markings on them which weren’t previously visible before the sealer was added. It looks as though some oil or adhesive may have been spilt on them. Some of the patterns are almost symmetrical.

Any ideas what could have caused this and how to remedy? Currently the company I used to lay the patio says as it was not visible when they laid the patio, it’s not their issue. I believe the slabs were a bad batch but struggling to prove it!

Any help would be greatly appreciated!

 

[KenGMac]

James McFadyen, good evening.

Can I suggest you use the "Search" function at the top right of this page.

Type in Stains on Indian Sandstone [or similar] and you will find a load of such questions and answers.

Ken.

 

[James McFadyen]

Hi KenGMac,

I’ve already searched for this and multiple variations of it but can’t find much, and certainly nothing that looks like the stains I’m seeing on my patio.

If anyone has any suggestions on what has caused the stains I’d be really appreciative.

 

[KenGMac]

James McFadyen, good evening, again.

Understood, as a question? how did you apply the sealer? was it poured from a can [or similar]?

The markings "look like" liquid spill. ?

Please do not think I am having a go at you but the patterns appear as stated above??

Ken.

 

[blup]

Looks like some sort of salts/efflorescence from within the porous material that is the sandstone.

If you purchased the materials direct you can take it up with the supplier. If the builder paid, it is his responsibility.

Blup

 

[James McFadyen]

I applied the sealer with a roller so it was evenly distributed. It’s also only on some slabs and not others - I think if there was a problem with the sealer or the method of application it would be on most/all of them. The patterns appear almost symmetrical on some slabs which makes me think something was spilt on them when they were packed but obviously no way to confirm this.

 

[Charlie George]

James McFadyen, good evening, again.

Understood, as a question? how did you apply the sealer? was it poured from a can [or similar]?

The markings "look like" liquid spill. ?

Please do not think I am having a go at you but the patterns appear as stated above??

Ken.

I agree with Ken here it looks like bleach/acid or something similar,they look like Kandla grey which i have and didn't seal as i find them easy to clean without,which sealer did you use,as some are better than others ?

 

[James McFadyen]

I used Lithofin Colour Intensifier sealant which was recommended to me by the landscaper who laid the patio.

I can confidently say that the sealer wasn’t spilt, but believe that something else may have been, and the sealer simply made it visible.

 

[Charlie George]

I used Lithofin Colour Intensifier sealant which was recommended to me by the landscaper who laid the patio.

I can confidently say that the sealer wasn’t spilt, but believe that something else may have been, and the sealer simply made it visible.

That is a good(and pricey) brand,so using a cheap one can't be blamed.post your pics on paving expert.com but it does look like a spill.

 

[KenGMac]

Just as an outsider here.

There has been a lot of posts on the board about discoloration of this material??

It is almost as if there has been some sort of chemical used during production that manifests itself when sealant is applied??

Ken.

 

[Charlie George]

Just as an outsider here.

There has been a lot of posts on the board about discoloration of this material??

It is almost as if there has been some sort of chemical used during production that manifests itself when sealant is applied??

Ken.

Hope they have toilet facilities for those kids in the quarry

 

[JohnD]

Just as an outsider here.

There has been a lot of posts on the board about discoloration of this material??

It is almost as if there has been some sort of chemical used during production that manifests itself when sealant is applied??

Ken.

Indian Sandstone is quarried and sawn, it is not a concrete product. It does show patterns of fossils in the surface, but not like the OP's problem.

I have some and it is fine, I insisted on a deep MoT base, and a good fall, brick pavers edging, it looks great.

(my neighbour laid his flat, with no drainage, and it is dirty, discoloured, and black with mildew)

 

[blup]

Recent batches (last few years) of indian sandstone have been reported as much poorer quality, more porous.

Blup

 

[Mike13]

Did the builder use pva? slurry? on the back, and might have poured it on before spreading it?