Four fire engines and two tanker battled for an hour to extinguish a blaze that engulfed the top storey of a Waikato house.

A Fire Service spokesman said they got the call to a Tamahere residence at 6.27am and the fire is now out.

"It was a large rural two-storey house and the top storey was well involved in fire."

The spokesman said the top storey is well damaged and a fire investigator will determine the cause of the blaze.