What's the singular form of pebble-dash? Here's the word you're looking for.
Answer
The noun pebble-dash is uncountable.
The singular form of pebble-dash is also pebble-dash.
Examples
On the other hand, the rest of the family moved east and ended up in Basildon, a rather unfortunate sprawl of pre-fab concrete and pebble-dash on the Thames Estuary.