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We spent years laying paving of all types and would always lay a wet concrete base, 100mm for traffic and 75mm for patios both on hardcore. Slabs would then be laid on a 25mm wet mortar bed or block paving on 40mm consolidated sharp sand. In 40 years we never had to go back to repair/lift/relay/re-point etc we were in it for the long term and that was good enough for me and our many, many customers. I fear though that times are a changin'.
it seems to me the method of laying slabs onto a mortar base which is tern on a fine hardcore bed is too susceptable to movement and cracked slabs. The reinforced concrete method is more stable and easier to lay on once the concrete has set, just more pricey.
You won't get me arguing with that Josh!!
I've heard of this method but don't use it. Higher costs and additional processes have stopped me going down this route though i take peoples point regarding strength. I do mainly domestic and lay on min 100mm type one/hardcore sub-base and then 50mm full bed 6:1 bedding mortar and in 15plus years i've never had any problems. I've been back to check on jobs. For me the main issue is a sound base and make sure soft spots are properly excavated and when you compact do it properly. Can't tell you how many times i have seen people make a single cursory pass with a wacker and also with a lightweight version. Use the right kit, do the job properly and there''s no need to spend more on overkill solutions.
Hello.
It very much depends on the scenario in which you are laying the slabs.
As a guide, if you have good solid ground to lay on, 100mm of compressed grade 1 mot over non woven membrane is a good base for paving.
If you choose to lay on concrete then the same depth of concrete with reinforcing mesh through the middle over dpm is a sufficient base. Ensure you use a non porous pointing material for any paving that is bonded to its base. If you wish to use a porous resin based pointing material you should use a porous sub base and binding material. Consider using a slurry bond on the back of your slabs when using a bonded method.
One other pint to note is that concrete should be allowed to dry thoroughly before laying your slabs and ofcourse be sure to dampen your scalpings before compacting and laying. These Are our minimum specs if the ground is clay or very soft then consider upping the spec from here or consulting an engineer.
All the best
I have always used type 1 sub base in most situations. I'm wondering what you guys who use reinforced concrete do about expansion joints in the concrete? My understanding is that the concrete will expand and contract and eventually crack if these are not put in where there is a large area of concrete.