Early Saturday morning fire crews spotted a flare up at the Johns Manville Company in Winslow Township.
Several fire engines and tankers were called to the scene to assist in the firefight.
Firefighters have been at the warehouse since Wednesday morning, when the initial fire started.
The Johns Manville Company produces insulation and roofing material.
A demolition crew had been brought in to move around the smoldering piles of products.