Sandstone or limestone

[tench0771]

I cleaned a large patio area haven’t got pic but I used a fsc on the main bit but as I was rincing down noticed quite a lot of small flakes of stone that has come off ? so decided to finish the rest off with lance wide fan jet low pressure but it was still flaking off you can’t notice it buy looking as the patio thankfully soft washed it came up perfectly but never had this before customer was over the moon with it but was worrying anyone had this problem? It looks like sandstone but could it be limestone as it’s so brittle

 

[Truckcab79]

I cleaned a large patio area haven’t got pic but I used a fsc on the main bit but as I was rincing down noticed quite a lot of small flakes of stone that has come off ? so decided to finish the rest off with lance wide fan jet low pressure but it was still flaking off you can’t notice it buy looking as the patio thankfully soft washed it came up perfectly but never had this before customer was over the moon with it but was worrying anyone had this problem? It looks like sandstone but could it be limestone as it’s so brittle

Almost certainly sandstone. It’s formed naturally in layers and sometimes they separate. Freeze-thaw will exacerbate it. Doesn’t matter. Once they’ve flaked off you just have a slab with a more riven section than it started with.

 

[K in Kent]

Almost certainly sandstone. It’s formed naturally in layers and sometimes they separate. Freeze-thaw will exacerbate it. Doesn’t matter. Once they’ve flaked off you just have a slab with a more riven section than it started with.

Yeah I agree and with the riven surface you can take off a layer from the entire slab in an instant. Always best to use minimal pressure and wider fan when possible or FSC.
If it's got heavy algae / lichen let the hypo do all the work and soft wash is another option that delivers same results as p/w.

 

[Pjj]

Hears one we did a few weeks ago hypo mix then a very light pressure wash. To be honest could have hypo it and light rub with a broom and rinse and it would have been ok .

 

[tench0771]

ill take some pic when i clean windows next

 

[tench0771]

 

[tench0771]

 

[tench0771]

Never seen sandstone like this before very brittle

 

[Herm]

100% that's Indian sandstone.

 

[K in Kent]

100% that's Indian sandstone.

Yes it's got to be with that colouring in the stone. I'm no geologist but would put money on it

 

[Iron Giant]

Yup, Indian sandstone we had it our last house bits would come off every now and then.

What strikes me about the photo is why on earth they put that brown coloured one in with the grey

 

[Truckcab79]

Yup, Indian sandstone we had it our last house bits would come off every now and then.

What strikes me about the photo is why on earth they put that brown coloured one in with the grey

Probably bought as a ‘project pack’. Generally sold as grey or buff. Used to be more regular in appearance but now the two options seem more or less identical. I always make the client aware of this as it’s entirely normal to lay a lovely even coloured ‘grey’ patio and then as soon as it’s wet you’ve got every colour from grey to orange to pink to cream. It’s like two entirely different stones. We tend to lay Kandla if the client is put off by the colour difference.