Construction work has spiked for a second straight quarter, far outpacing market expectations, but economists suggest the numbers could flatter to deceive.

The value of construction work done jumped 15.7 per cent in the September quarter to $61.9 billion, mainly bolstered by a 33 per cent surge in engineering work, including mines, roads and bridges, to $34.2 billion. Total building work on homes and non-residential buildings such as offices and shops fell…