Minimum bedding layer for flags - Thin mortar or adhesive?

[JamesinFrance]

Hi - I have just finished building an in-ground swimming pool. The reinforced concrete surround (150mm) is in place and is absolutely level (with correct fall) finished with a steel float. I originally intended to fix the 500 x 500 x 30 flags to the base with a thick bed external tile adhesive and the allowance made for this around the pool is 15 - 20 mm. The cost of the adhesive has risen dramatically recently, As a cheaper alternative, can I lay them successfully using a thin cement mortar bed perhaps with an additive? The whole area is raised and the edges of the flags would be open to the elements so adhesion might be an issue. The sand I would have to use would have to be a builders sand - the sharp sand here is very coarse and not suitable for a thin bed. Any advice would be much appreciated.

[Tony McC]

SBR mortar. Reduces your working time but sticks like the proverbial to a blanket!

[GB_Groundworks]

any recommendation on which make of sbr, about to lay some 420x560 injun stone on a stone wall as copings and the kids will be climbing over them, so going to use sbr in the mix just wondered if one was better than the other. local bm is all sealcrete gear.

giles

[Tony McC]

I used to get mine from IFS in Newton-le-Willows, but I don't even know if they are still in business. Ronafix is the trusted brand, but I see that even B&Queue are now selling it, so it should be fairly easy to get a known brand at your local BM