Forum: Other Pavings
Topic: Stone setts question
started by: Firesi71
Posted by Firesi71 on 05 Sep. 2019,17:33Apologies if this has been asked before but i couldnt find it ( new to site though!)
I will shortly be laying reclaimed stone setts to my driveway. Im getting someone in to dig out to 300 mm which will allow me enough depth for the base , bedding and stones which vary 6- 7 inch deep. Am i correct in thinking the bedding should be 4\1 grit sand wih a 4 inch mOt base?
Also dos the beddinG layer need a waterprrofer adding to it?
Any help is much appreciated
Posted by Tony McC on 07 Sep. 2019,21:23The best guide can be found < here > for rigid/bound construction.
For a driveway, I'd look for minimum 100mm of DTp1 to give a firm sub-base, then bed the setts in 75-100mm of ST1 or C7.5 concrete. You could use the 4:1 grit sand mortar if you prefer, but a concrete bulks up the bedding with gravel/coarse aggregate and can save a few quid. It also provides better support for heavier setts (and 1t 150-175mm depth, they *will* be heavy!) over the first 24 hours.
The downside is that a concrete mix is a little more awkward to, compact, more resilient, but you should soon get a 'feel' for the ideal surcharge that gives just enough upstand to allow the setts to be properly bedded-in without having the wallop them too much.
No real need for a waterproofer unless you have vulnerable sub-surface structures, such as cellars or vaults.
Posted by Firesi71 on 18 Sep. 2019,21:45Thanks very much for the info.