Laying sandstone on steps - exterior tile adhesiv - Method to apply paving to patio steps

[TazMan]

My patio steps (30mm tread x 17mm riser) are made up of a concrete base.

My contractor said he will use exterior waterproof tile adhesive (10mm) to stick the sandstone (40mm thick) paving to the concrete steps. Is this correct?

Also, must there be an overhang of tread against riser? I read on this site that a 25mm-50mm is required. I've seen some places with and without. My contractor has messed up the measurements when pouring the steps, so my bullnose paving has no overhang over the riser.

I am very nervous after having cowboys previously who left me with no garden and who are more interested in payment than doing things properly.

Incidently, is it ok to use big (30cm chunks) of conrete boulders instead of MOT type 1 to fill a trench? I've read about the 37mm washed gravel bits and double layer compaction.

[seanandruby]

My patio steps (30mm tread x 17mm riser) are made up of a concrete base.

My contractor said he will use exterior waterproof tile adhesive (10mm) to stick the sandstone (40mm thick) paving to the concrete steps. Is this correct?

Also, must there be an overhang of tread against riser? I read on this site that a 25mm-50mm is required. I've seen some places with and without. My contractor has messed up the measurements when pouring the steps, so my bullnose paving has no overhang over the riser.

I am very nervous after having cowboys previously who left me with no garden and who are more interested in payment than doing things properly.

Incidently, is it ok to use big (30cm chunks) of conrete boulders instead of MOT type 1 to fill a trench? I've read about the 37mm washed gravel bits and double layer compaction.

Are you sure it's not 300x170 tread and riser? If so that's fine. Should be using mortar, yes ideally should be an overhang.

[TazMan]

yes, 300mm x 170mm (got cm mixed up - was a late night).
Thanks Sean.