Granite block paving

[derekoak]

I was attracted to Indian stone block paving by Tony's page. Especially that the stone splits well. When I went to look at the display in Ellesmere Port I was swayed by the 50mm Natural Paving granite blocks. Largest 300 x 200mm
I can imagine that granite will be harder to split. Is it just a case of getting a more powerful splitter, for example one for clay paviors or even a hydraulic one or will I need to cut everything with a diamond blade?
Are there any other problems with granite? maybe it is more slippery than sandstone? There is a price premium of only £1/sq.m over the comparable sandstone .

[williams]

You will need a diamond blade and still they are very very solid.

[derekoak]

You will need a diamond blade and still they are very very solid.

Is granite just too hard to split even with a hydraulic splitter or does it split in the wrong place? I think these blocks are sawn top and bottom and the top "flamed". I dont know what that is but it makes the top a little less smooth
If it splits wrong Would a mark with a diamond blade encouage it enough to split right?

[derekoak]

I have trialled a hydraulic splitter on a 300mm x 50mm thick cut. It split well.

[Tony McC]

Granite is, nowadays, always split using an hydraulic splitter. If you have a sufficiently beefy manual splitter (cam-action) and weigh more than around 100kg, it is possible to snap larger pieces of granite, but it's helluva lot of hard work.

We have a splitter that uses a simple bottle jack to apply the pressure. My owld fellah had it since the 1960s and used it to split granite kerbs down to the required length. It weighs around 300kg and had to be lifted on and off the wagon using the hiab, but it is a grand tool.

[GB_Groundworks]

i bid on one at an auction the other day, you could tow it and then stand it up to use it, and was powered by a electric motor powering hydraulic pump. i dropped out at 1500 as i didn't really need it

[derekoak]

I now want to put a feature in my granite area. It would be easy, (no cutting) to put in a hollow square of a different colour. I have enough edging cobbles left to do this. The edging cobbles are irregular and I assume they will be laid on concrete like the edging.
I think my plan is to:
lay the body of the drive in granite, as if the feature was not being put in,
and then at some point lift the granite blocks in the area of the feature, carefully dig out the bedding sand and lay concrete then tap in the cobbles as if they were edging.

They would end up with 50mm of concrete under them like the edge course, which is retained by kerbs.
Is this the best way?
Do I wack down the granite all over before I start on the feature?
deleted jointing question

[GB_Groundworks]

I imagine my last job is to point the cobbles up. It seems it would be quick to: on a dry day brush dry sand and cement into the joints and then, water and wash the cobbles off. Is this the best way?

no hardly ever works, its a quick solution but provides only a short term solution, maybe look at polymetric based jointing compunds like rompox or gtfk. see the pointing page on the main site for more info.

but i'd strongly advise against a dry mix swept in.


jointing setts

gi

[derekoak]

Thanks Groundworks,
I have read again the main pages and see what you mean. It will either be pitch or grouting slurry for the cobbles.

Having read about "jointing sand first or after compaction" I dont know what to do. The main paviors are sawn granite. I dont know whether To joint first or compact first. The granite has no spacers. Do I put them tight or try to space 2mm? If I space 2mm and compact first I think they will move about. There is no chamfer so it is only the strength of granite that will stop it spalling.
If I joint first I will have difficulty removing blocks for the feature. At the moment I feel I must space 2mm and joint first

[Tony McC]

That piece about 'jointing before or after' applies to concrete and clay block pavers ONLY. It is completely irrelevant for granite setts, which need to be jointed using a cement mortar, a resin mortar or pitch.

[GB_Groundworks]

we had our drive at home cobbled about 12 years ago with granite reclaimed road cobbles and they used a slurry to point them, but there was some surface staining from where they brushed it in. this soon wears off or if your impatient like my dad he had the whole drive sand blasted brought them out lovely.

[slimdotjim]

I think there is some confusion here, as I understand it your laying calibrated granite block paving with a feature in the middle using granite sets (cobbled street style). Personally and I'm sure I will rightly be corrected if wrong I would lay the granite block paving the same as any block paving and would use jointing sand before compaction, I think Pavestone do natural stone blocks without nibs so might be worth checking there laying guide.(dodgy website) Mark the position of your feature and edge it with your granite block paving on mortar the same as you did with the perimeter edging for the drive, make sure this follows any falls and try to keep it square to as many perimeter edges as you can. screed and lay block paving Fill the resulting void with concrete, bed your granite sets allow to go off and compact the block paving, not the sets, joint the sets with a jointing compound if the budget allows. Taking the blocks out after laying the drive is also a valid way and in some ways is technically easier, just remove the blocks before compaction once you get the first one out they come up easily, then do the same as above, try not to put weight on any unsupported edges
cheers Jim

[derekoak]

Yes there was some confusion I obviously did not explain clearly enough. Sorry.

Slimdotjim has it right except the cobbles are limestone, which makes no difference to his advice.

If I lift the sawn granite blocks from where the feature will be before compaction and lay the limestone cobbles on 50mm concrete. I will have to board out the edges of the sawn blocks to spread the load and keep them clean. I will have to set the cobbles the same distance below the sawn granite blocks as the edging will be. Then wait for the concrete to set (2 days?) before I use the jointing sand on the sawn granite then compact the granite, Avoiding compacting the cobbles by mistake.

Is it right then that I must lay these sawn granite blocks with a gap without the help of the spacers on other block paviors to leave room for jointing sand?

[slimdotjim]

Hello
Do your blocks have a manufacturer, they may be able to offer advice. Do the blocks butt up very close or are there gaps left 3mm would be enough. Using spacers would be very time consuming, personally I would do it by eye with the aid of a string line to keep me on the straight and narrow, working off a board to minimise disturbing the blocks, a nice light piece of thin ply would be ideal.
Cheers Jim