An area of Portal St has required a temporary hot mix repair after a product failed to adhere following road works carried out on March 8.
The work was part of Whanganui District Council's $2 million annual reseals programme and contractors used a polymer modified emulsion to seal the road.
A spokesperson for WDC said the product performed well despite failing to adhere in one area and a review was conducted into why that happened.
The review revealed that a block of silt had entered through the chip stockpile and had broken up through the roller spreader truck.
"This created a layer that prevented chip from adhering to the emulsion in an isolated area," the spokesperson said.