patio circle

[johnlewis]

will be putting a patio circle down and have dug out 150mm down to create my level concrete base.

is it possible to use an exterior tile adhesive to stick down the calibrated indian sandstone with on top of the slab?

 

[WabbitPoo]

yes

will it work? might not as sandstone is soft and prone to flaking.

do it the right way from the off.

 

[johnlewis]

the back is ridged from the calibration

sharp sand cement is best then ?

 

[r896neo]

Use a normal sharp sand based mortar.

No matter how well calibrated there will still be variations of 5mm of more in thickness and also uneven thinner spots less than the calibration depth where there was a delamination in the stone when split.

Don't use a concrete base. 75-100mm of well compacted type 1 and a 50mm mortar bed is plenty. You have an outside chance of giving your self problems with a concrete base as its pretty impermeable to moisture.

 

[johnlewis]

cheers

sadly already started poring the concrete , had some old rubble to get rid of so it went underneath.

i cant see the concrete being a problem , 120mm thick with a run off .

the ground is very hard compacted clay