Fixing to concrete - Additives

[kev johnson]

hi guys, i am laying sandstone sets to the last metre of a gravel
drive before it meets the road way to stop the gravel spilling on to the road however there is already a concrete base laid and i have very little clearance below the gates. can the sets be bonded to a mortar bed if so how thick and what sort of mix will be needed . the height issue only relates to the first couple of rows as the drive falls away.is there any additive i could mix with the mortar to give a strong thin bed. as i said its only relates to the last 300mm . i was thinking of a 10mm joint grouted with romex dran
cheers
kev.

[GB_Groundworks]

sbr can be added and used as a bond bridge, theres a lot on the main pages about it

[Pablo]

you'll need to lay them on a bed of at least 20mm due to the varying thickness of the setts. If the have is fouling them then could you remount it slightly higher. Romex dran isn't suitable for vehicles and the tyres will push the stone into it.