Change in paving thickness & bedding - Change in paving thickness & bedding

[biomike]

I was orginally putting down 50mm block paving with 50mm bedding in my rear garden. I am now thinking of putting down 600 x 300 paving stones . I have already put down the 100mm mot sub grade allowing 100mm for the block paving. Can i put down a thicker bedding to make up for the difference as the flags are 20mm to 35mm thickness. Or will this cause a settlement issue in time to come.

One of the the paving stones i was looking at was granite 600 x 300 x 20mm http://www.nustone.co.uk/silver-grey-gr ... 0x600.html They say it is very durable but 20mm seems very thin?


By the way thanks for all the advice on the website i couldn't have got this far without it.

Thanks

Michael

[Tony McC]

Build up the sub-base rather than increase the bed thickness. Those granite flags must be laid on a full mortar bed. 20mm is just about the minimum thickness they can get away with but it really does need a robust supporting bed to avoid to many breakages.

[biomike]

I have decided to go with the 20mm granite flags which are 600 x 300 for an area of 36 sq metres. Have looked at the recommendations for laying granite flags i would like some clarification.

Sub Base

The sub base is 150mm made up of 50mm broken hardcore and 100mm of MOT1 on top


Bedding

I was going to go for a cement bound bed of 50mm (10:1 mix) with a semi-dry slurry as the stone is porous. Then i read 'some designers prefer to have the more porous granite pavings (eg: G603) laid onto a no-fines bedding because this is considered to eliminate the risk of moisture being in contact with the underside of the paving units and thereby reduce the risk of unsightly damp patches or picture framing'

It goes on to suggesting a 6mm cement bound bedding for porous granite / Slurry Coat - Primer - Bonding Bridge. Please can you explain the best route to take.


Jointing & Grouting

I am going to allow a 5mm gap between stones. Please can you advise me the best course of action.

[seanandruby]

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