Jumpy tiles just under pressure

The case of exploding tiles on the floor of a Far North service station may remain a mystery as the owners move to have the floor fixed.

A section of tiles on the floor at the GAS service station at Coopers Beach popped and cracked - the same time a 4.3 magnitude quake, 20km south of Seddon in the South Island, was measured last month.

A GeoNet seismologist in Wellington said he was not convinced the Northland incident was related to the big jolt felt hundreds of kilometres south.

But a Northlander working overseas has offered a possible solution to the mystery.

Speaking from Jakarta in Indonesia, Mangawhai engineer John Dickie said he had twice experienced the exploding tile phenomena in flats while living in Indonesia.

About 15 years ago tiles of the floor popped and cracked while he was in Surabaya.

"We believed it was very dry weather causing the clay foundations of the building to shrink and put pressure on the tiles, and they popped with quite a bang and looked like the ones in the Far North," Mr Dickie said.

Then in Jakarta about three months ago the same thing happened with some wall tiles in the bathroom. "The pressure builds up and finally something triggers the popping."