You have a great information base in this web site!
My question is that I live in a climate with freezing temperatures for up to 4 months and i have been told that i should not mortar my joints for the flags without a concrete base. With your methods is this ok? Will my joints push and crack. Should I mix cement in the screeding process. I prefer the mortared look and value your advise in this process. My flag is approximately 40 - 50 mm thick and will be delivered in a day! Any info would be great.
thanks
scott
Mortar joints
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84-1093879891
The usual method for paving in very cold climates is to ensure the bedding, the jointing an dthe flags themselves all have similar or identical expansion/contraction rates so the whole pavement acts as one, almost. Therefore, the bedding needs to be a concrete, a C20 equivalent (I'm not sure what spec is used in your homeland, but see the Concretes page for a more detailed explanation of what constitues a C20) with an added frost-proofing agent. Similarly, the jointing mortar should be a Class II with added frostproofer. The bedding should be at least 100mm thick, but I know of some instances in N.America where a 250mm thick concerte bedding layer has been used, laid atop a compactyed sub-base.
Depending on the size and layout of your paving, you will need to provide movement joints at regular intervals. 3 metre centres seems to be a popular choice for movement joints in flagged patios and driveways, but final choice depends on site conditions and bed thickness.
Depending on the size and layout of your paving, you will need to provide movement joints at regular intervals. 3 metre centres seems to be a popular choice for movement joints in flagged patios and driveways, but final choice depends on site conditions and bed thickness.