Unbound bedding

[extwo]

Hi, I am new to all of this but have finally decided to bite the bullet and do a patio for my back garden. I have been reading as much as I could on the main site and have a question about unbound bedding.

The plan is to lay patio slabs on an unbounded bedding of grit sand on a sub-base. In the article for bedding it states

"As a very, very general rule, flags 450x450mm or larger are usually laid on a bound (rigid) bed, while those of 450x450mm or less are often laid on an unbound (flexible) bed. However, there are many examples of smaller flags being laid on bound bedding and larger flags being laid on sand."

My question is what is the reasoning behind this? Using my (flawed?) logic, it should be the other way round. A larger, heavier flag would be less prone to moving so could be put on an unbound bed where else a smaller flag could move if it was unbound. So can someone please point out what I am missing.

Thanks.

[Tony McC]

That it applies to a very specific group of paving known as "Small Element". It does not apply universally to all types of flagstone paving.