Had a new patio last week. Mostly pretty good, laid in record time and really quite an improvement.
But I noticed at the weekend two slabs have indications of de-lamination, and a third is actively de-laminating. By this I mean the wrinkly contoured surface has/is breaking off leaving a smooth stone under.
I'm guessing this could be normal, up to a point, as the "patterned" layer is very thin and brittle, and as soon as it starts cracking then it will probably go across the whole slab.
But is this more sinister - have I been sold cheap stones with stick-on contours? They can't have cashed the cheque yet... :-)
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Not auguring well for longevity. A bit of water and frost and it will be coming off in lumps?
Could be a dud batch.
Looked up 'paving slab spalling' - www.pavingexpert.com/jointing15.htm
Says butt joints make it worse. (no tittering).
Last edited by: Manatee on Mon 3 Feb 14 at 15:34
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Having laid slabs for the council many years ago, as a college vacation job, I can say that I've never come across what you describe before, Smokie.
Did the 'workmen' live in caravans, only have a mobile number and greet you with "top o' da mornin' t' ya"?
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>> Having laid slabs for the council many years ago, as a college vacation job, I
>> can say that I've never come across what you describe before, Smokie.
>>
>> Did the 'workmen' live in caravans, only have a mobile number and greet you with
>> "top o' da mornin' t' ya"?
>>
Racist ;-0
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Actually no, respected company with tons of good reviews on Checkatrade over a number of years. Workmanship and commitment were nearly faultless, it's just the stone quality I'm concerned about.
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You need to speak to them....shouldn't be doing that after a few days..
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>>Checkatrade
Thanks for the link, Smokie.
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What kind of stone?
Is it basically Sandstone / limestone? It was laid down under water and over time is compressed - the layers are caused by slight changes in the size of the sand grains and the direction of the water & currents. If mica gets in between the layers of sand there will be a tendency for the sandstone / limestone to sheer along the mica layer.
Around the edges just now - when water( & ice) get in it can spread into the whole slab. sandstone/limestone is quite soft. Slate is very hard (metamorphic (heat treated) fine clays but the mica between the slate make it split along the strata of the bedding layers.
Did a wee bit ( 2years) geology at Uni 50 years ago - hence a little knowledge but is a bit foggy - as is much of my knowledge these days.
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It's sandstone. They only finished laying it on Friday, and only over the weekend did I have enough light to do a proper inspection.
Last edited by: smokie on Mon 3 Feb 14 at 19:11
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So it's natural sandstone? Not a concrete product?
If so, it's not that unusual for it to cleave along the plane it was deposited in.
If they had an uneven surface then they were split rather than sawn, so will have a random finish anyway. I've seen (Yorkshire sandstone) flags do that.
Where's that builder?
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Orf to bed.
I hate patios with a passion.
Get the supplier details and have a Google. If the builder supplied then he's gotta take the rough with the smooth (pardon the pun).
MD
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But surely if its sandstone its going to weather and spall anyway? Thats what sandstone does.
Friend of mine lives in a town where the house are literally wearing away!
Last edited by: Zero on Mon 3 Feb 14 at 22:30
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If you're buying Indian sandstone please make enquiries as to its source:
www.indianet.nl/a0703.html
Last edited by: CGNorwich on Tue 4 Feb 14 at 00:23
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Smoke, did you get to the bottom of this?
It looks as if we will use stone for our paved area behind the now house and my PM is looking at prices now.
The merchant(s) he is talking to all say they get it from Marshall's who say theirs is ethically sourced etc., I'm quite 'woke' myself on this and neither do I want any of our visitors saying my patio was quarried by child labour!
The other thing of course is quality. What was this issue with yours, if there was one?
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I have had hand split indian sandstone slabs down for two years now. Because they are hand split, some delamination is inevitable and its why they can be hand split. However you end up with stable slabs once the "lose" bits have come off.
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Apparently ships arrived from India with blocks of stone as ballast. When one was dropped and it delaminated naturally the idea came to mind to use it as the source of paving slabs.
Like desking, it is frequently laid upside down. The rough surface should be underneath supported by the cement mortar. The top should be pretty smooth. With decking the grooves should be underneath to promote water dispersion.
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It's not got any worse and I suspect it was just maybe some frost or something which further weakened an already weak thin layer which just then comes off at some point in the future. I suppose they'd call it settlement or something. Anyway, although generally it wasn't a great job, I'd have the same stones again so I guess it's not that bad...
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We learnt the other week that the granite work-tops in our new home are sourced from India...doubts have been raised as to whether they've been ethically mined. It's a real minefield - when in Vietnam and talking to our guide (who was local), he pointed out the deforestation of hillsides to supply the demand in the West and China. Makes you think twice - takes decades to fix that.
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Quite a few decades to re-form enough granite for your kitchen worktops I expect!!
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>> We learnt the other week that the granite work-tops in our new home are sourced
>> from India...doubts have been raised as to whether they've been ethically mined.
Well dont dump them just because they havent, thats adding insult to injury, use them with gratitude and honour the poor rugger that suffered.
Last edited by: Zero on Thu 15 Jul 21 at 22:08
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We're hoping to re-use them or sell them on
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My young bitch has come into season. If you dont know they drip a lot of blood. In the house the use of nappies keeps the floor clean. Has to be off in the garden for toileting reasons.
Subsequently she has stained the indian sandstone patio. I hope Idris doesn't go missing, the patio has "crime scene" literally all over it.
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Indian slabs "de-laminating" - Manatee
