Hi,
I've just taken delivery of Bradstone sandstone slabs in a 15m2 patio pack. I'm worried that the slabs are too thin (approx 22mm thick) especially the 900*600 slabs. The slabs are intended for a general use patio with the only real weight bearing item being a three-seater wooden bench. My inclination is to pay for the slabs to be returned. Have you any experience of this type of slab?
Thanks,
dkb
Sandstone thickness - Too thin?
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Bob_A
- Posts: 861
- Joined: Wed Feb 27, 2008 9:30 pm
- Location: SE London/ NW Kent
I can give a DIYers answer.
My 22mm Indian Sandstone is by Stoneflair. As Bradstone own Stoneflair you'll probably find it all comes from the same place.
Reason I chose 22mm is because it's easier to lay, uncalibrated slabs are ok for a professional but would've been too difficult for me as my first job.
As long as you use a good sub-base and a slightly wet sand/cement bedding layer I'm sure they'll be ok.
Just don't try to lay them on sand only!
Just be careful with the 900x600's.
Check them for hairline cracks before you start. I did get a couple like that, they sounded hollow so I tapped them before I started to lay them and they broke!
Wasn't a problem as I was sent replacements free of charge. I kept the old ones and used them for offcuts.
Treat the 900x600 with respect. Get the bedding layer as best as you can so you can tap them down into consolidation rather than bashing them.
Just be careful, for a patio they'll be fine. (If not I'm fooked!) Just don't drive a 4x4 on them.
If a tradesman is doing it and makes a fuss about them being too thin then I'd reject him and get a proper paver in.
My 22mm Indian Sandstone is by Stoneflair. As Bradstone own Stoneflair you'll probably find it all comes from the same place.
Reason I chose 22mm is because it's easier to lay, uncalibrated slabs are ok for a professional but would've been too difficult for me as my first job.
As long as you use a good sub-base and a slightly wet sand/cement bedding layer I'm sure they'll be ok.
Just don't try to lay them on sand only!
Just be careful with the 900x600's.
Check them for hairline cracks before you start. I did get a couple like that, they sounded hollow so I tapped them before I started to lay them and they broke!
Wasn't a problem as I was sent replacements free of charge. I kept the old ones and used them for offcuts.
Treat the 900x600 with respect. Get the bedding layer as best as you can so you can tap them down into consolidation rather than bashing them.
Just be careful, for a patio they'll be fine. (If not I'm fooked!) Just don't drive a 4x4 on them.
If a tradesman is doing it and makes a fuss about them being too thin then I'd reject him and get a proper paver in.
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London Stone Paving
- Posts: 2199
- Joined: Mon May 10, 2010 1:07 pm
- Location: Surrey
- Contact:
Andrew
I thought i would post the answer on here so the information is available to all. 22mm calibration is the new thing with Indian sandstone. All the suppliers from india are now really pushing calibrated material.
Its good for the Indian suppliers because they can squeeze a bit more money out of there customers. The Indian suppliers will also say that it is good for the importers. Generally Indian sandstone has always been supplied in 25-35mm or 25-40mm. This allows for approx 390-420m2 per container depending on the willingness of the supplier to stuff the maximum into the container. However the introduction of 22mm calibrated material now means that 525m2 can be stuffed into a container. This brings the unit cost for the supplier right down.
So there you see the advantages to the manafacturer and also to the importer. However you may ask now what are the advantages to you the customer? Well the truth is that unless Uk importers are bringing the price down (which in my experience they are not) for the end user then there is no advantage to calibration. Obviously calibration will make installation a bit easier but any half decent paver will not struggle to put paving down whatever the thickness variation.
As a company we did look at introducing calibration but we just did not quite trust the 22mm. When we looked at calibrating to 25mm it did not make economic sense to do so.
My honest opinion is that for your small project it would probably be ok and you may get away with it. You need to consider if you are happy to "get away with it". I would imagine that the slabs were not cheap and by the time you have finished the whole project it will have cost you a lot of money. So it is your decision to weigh it up. There is no shortage of thicker paving on the market for a similar price if you decide you can't live with it.
Hope I have answered your concerns. If not get back in touch
Steve London Stone
steven@londonstone.com
I thought i would post the answer on here so the information is available to all. 22mm calibration is the new thing with Indian sandstone. All the suppliers from india are now really pushing calibrated material.
Its good for the Indian suppliers because they can squeeze a bit more money out of there customers. The Indian suppliers will also say that it is good for the importers. Generally Indian sandstone has always been supplied in 25-35mm or 25-40mm. This allows for approx 390-420m2 per container depending on the willingness of the supplier to stuff the maximum into the container. However the introduction of 22mm calibrated material now means that 525m2 can be stuffed into a container. This brings the unit cost for the supplier right down.
So there you see the advantages to the manafacturer and also to the importer. However you may ask now what are the advantages to you the customer? Well the truth is that unless Uk importers are bringing the price down (which in my experience they are not) for the end user then there is no advantage to calibration. Obviously calibration will make installation a bit easier but any half decent paver will not struggle to put paving down whatever the thickness variation.
As a company we did look at introducing calibration but we just did not quite trust the 22mm. When we looked at calibrating to 25mm it did not make economic sense to do so.
My honest opinion is that for your small project it would probably be ok and you may get away with it. You need to consider if you are happy to "get away with it". I would imagine that the slabs were not cheap and by the time you have finished the whole project it will have cost you a lot of money. So it is your decision to weigh it up. There is no shortage of thicker paving on the market for a similar price if you decide you can't live with it.
Hope I have answered your concerns. If not get back in touch
Steve London Stone
steven@londonstone.com
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dkb
- Posts: 2
- Joined: Tue May 18, 2010 11:10 am
- Location: renfrew
Steve,
Thanks for your excellent response. You've echoed my sentiments entirely. I was taken aback at how thin the slabs were when I opened the packing case. To be honest I was a bit concerned at even lifting the 900*600 slabs in case they would break. Also, I have to add, I felt a bit foolish at not knowing the thickness of the slabs before I ordered them. I simply thought a slab was a slab and not a wafer. The slabs were fossil buff sandstone and the cost for a 15m2 pack was £345 - just about my budget. You suggested that there are thicker slabs on the market at a similar price. Any recomendations you might care to make? All we are looking for is a riven type slab, sandstone if possible but not necessarily so, with a mix of slabs that we can make a pattern from.
Thanks again for your response,
dkb
Thanks for your excellent response. You've echoed my sentiments entirely. I was taken aback at how thin the slabs were when I opened the packing case. To be honest I was a bit concerned at even lifting the 900*600 slabs in case they would break. Also, I have to add, I felt a bit foolish at not knowing the thickness of the slabs before I ordered them. I simply thought a slab was a slab and not a wafer. The slabs were fossil buff sandstone and the cost for a 15m2 pack was £345 - just about my budget. You suggested that there are thicker slabs on the market at a similar price. Any recomendations you might care to make? All we are looking for is a riven type slab, sandstone if possible but not necessarily so, with a mix of slabs that we can make a pattern from.
Thanks again for your response,
dkb
dkb
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Bob_A
- Posts: 861
- Joined: Wed Feb 27, 2008 9:30 pm
- Location: SE London/ NW Kent
What Steve says about cramming more into containers makes sense.
But just to put things into perspective I had a couple of naff slabs out 0f 65sq/metres which were replaced fuss free and if a first time DIYer (with first class advice from the regulars on here-thanks chaps!)had no trouble why should you.
But if you're still uncertain then it's probably best to change them.
Good luck with your decision and enjoy your patio
Bob
But just to put things into perspective I had a couple of naff slabs out 0f 65sq/metres which were replaced fuss free and if a first time DIYer (with first class advice from the regulars on here-thanks chaps!)had no trouble why should you.
But if you're still uncertain then it's probably best to change them.
Good luck with your decision and enjoy your patio
Bob
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London Stone Paving
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- Joined: Mon May 10, 2010 1:07 pm
- Location: Surrey
- Contact:
in response to DKB & Bob
Now that Andrew has mentioned that the stone is fossil buff then 22mm is in my opinion not strong enough. Fossil buff is one of the softer varieties of Indian Sandstone. If the stone was one of the kota Indian sandstones such as Raj green, Kandla grey, Autumn brown then 22mm would be much more acceptable (the kota stones are tough, especially the kandla grey which is mega).
You also need to consider that even though the stone is sold as 22mm thick, cutting tolerances of minimum +/- 2mm will apply. this means that some of the stone will be 20mm or even 19mm or 18mm at a worst case scenario.
Sounds like things have worked out ok for Bobs project and it is unlikely that it will cause him any problems now its all been installed correctly.
We sell thousands upon thousands of m2 of indian sandstone every year. Our best customers are landscapers and ground work contractors and in my experience if we started to try and sell them 22m material they would not be comfortable and I would lose business, no question about it.
Hope I have answered the queries ok
steven@londonstone.com
Now that Andrew has mentioned that the stone is fossil buff then 22mm is in my opinion not strong enough. Fossil buff is one of the softer varieties of Indian Sandstone. If the stone was one of the kota Indian sandstones such as Raj green, Kandla grey, Autumn brown then 22mm would be much more acceptable (the kota stones are tough, especially the kandla grey which is mega).
You also need to consider that even though the stone is sold as 22mm thick, cutting tolerances of minimum +/- 2mm will apply. this means that some of the stone will be 20mm or even 19mm or 18mm at a worst case scenario.
Sounds like things have worked out ok for Bobs project and it is unlikely that it will cause him any problems now its all been installed correctly.
We sell thousands upon thousands of m2 of indian sandstone every year. Our best customers are landscapers and ground work contractors and in my experience if we started to try and sell them 22m material they would not be comfortable and I would lose business, no question about it.
Hope I have answered the queries ok
steven@londonstone.com
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lutonlagerlout
- Site Admin
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- Joined: Fri Aug 04, 2006 12:20 am
- Location: bedfordshire
decent well thought out answers there bob and steve (makes a nice change)
i have laid uncalibrated and calibrated and as a pro it doesn't bother me either way.
as far as i am concerned most injun stone is nothing more than tiles,the 100mm of type1 and 40-50mm bed is where the strength lies
if i had a choice it would be cut to 35mm,but the economics of the situation is to make it as thin as possible
TBH i find it more annoying some of the obvious crap that gets packed into crate,normally 1 -2 per pack of totally NFG flags
LLL
i have laid uncalibrated and calibrated and as a pro it doesn't bother me either way.
as far as i am concerned most injun stone is nothing more than tiles,the 100mm of type1 and 40-50mm bed is where the strength lies
if i had a choice it would be cut to 35mm,but the economics of the situation is to make it as thin as possible
TBH i find it more annoying some of the obvious crap that gets packed into crate,normally 1 -2 per pack of totally NFG flags
LLL