The Brew Cabin

Hi
I'm laying Marshalls Timberstones (38mm depth) over a 100mm Compacted Hardcore.
Can you please advise as to what depth my bed needs to be, should i use a 40mm 10:1 mix as in "How to lay Flags & Slabs" or Semi dry bedding material, depth ? as in " Mortars & Concretes".
Cheers
Slightly confused novice

p.s yet again Marshalls advise Full Mortar Bed only!!!

Hi Melanie,

the 10:1 or the semi-dry is fine for those flags - whichever suits you best, as, I assume, there won't be any vehicular traffic. There's not much difference between the two specs I give, anyway: both rely on a small quantity of cement to bind the sand/aggregate together sufficiently without trying to turn it into a rock-solid mass.

A full mortar bed is OTT, but is the usual recommendation from Marshalls and other manufacturers who really ought to know better, but who continue to get away with promoting the practice because it's allegedly easier for DIY'ers.

In our experience, it's actually harder to lay flags onto a wet mix, and there's no need for such a relatively high cement content. Use the semi-dry recipe of a 10:1 mix with minimal water content (if the sand is damp enough, there's no need to add any gauging water at all) and make the bed 35-50mm thick when compacted.

I'd be interested to hear how you get on with these Timberstones, as previous posters have reported they are a right swine to lay, particularly because of the uneven surface which they say is all but impossible to level with adjacent flags.

Good luck, anyway! :)