The Brew Cabin

I am laying a new patio. Do i dig down about 75mm and put dtp1 hardcore in then put a bedding layer of dry sharp sand and cement, 10:1. and then just lay the flags on that. because i have seen a five dot mortar mix being used all over and i am unsure with what will last longer. The patio already is in a bad condition. The patio holds a lot of water under it in the winter months and consequently water squirts up when walked on. Also the flags rock side to side, especially the ones on the driveway which i would also like to relay aswell. Also what mix of mortar would i use to bed bradstones cotswall blocks in to act as an edge to stop soil from spilling over.

many Thanks

Liam Booth

The correct way to lay flags is covered in some detail on the Laying Flags page.

You seem to be confused about the exact construction - if you "dig down 75mm" there's no way you could ever fit in a sub-base of DTp1, the bedding and the paving: a sub-base layer needs to be 75mm at the absolute minimum, and it's not always necessary benath a patio.

The spot-bedding method is crap. It is not allowed on site for commercial works and it should not be used for any form of paving for all of the reasons outlined on the Laying Flags page, regardless of what you see in garden construction magazines or manufacturers catalogues. It is more or less guaranteed to cause problems in the long term. You should use a full bed when laying flags, of either clean, grit sand or a cement-bound bedding such as the 10:1 bedding mix described on the site.

Mortar for your walling should be a Class II as described on the Mortars page.