Answer: flagstone

AnswerCrossword Clue
FLAGSTONE

Patio piece

FLAGSTONE

Flat paving rock.

FLAGSTONE

Paving material.

FLAGSTONE
Patio slab
FLAGSTONE
Hail author Irving?
FLAGSTONEPaving material
FLAGSTONETerrace surface, perhaps
FLAGSTONEFlat paving slab