Around 1500, water power was introduced in Norway to cut planks and boards, largely replacing hand-sawn planks and hewn boards. They were driven by water wheels, which had been used for centuries to power grain mills and stream mills.

However, the saws used small impact wheels, which achieved sufficient speed to drive the saw blade through the log.

The first saws were so-called "upright saws", which consisted of a single vertical blade. During the 18th century, saw frames with two or more parallel blades also appeared, allowing one to cut several boards at the same time. These were called "silk saws".

Most of the water sawmills at Eiker were flood sawmills located on small rivers and streams and only in operation during the spring and autumn floods. However, there were also larger sawmills, with vintage sawmills that were in continuous operation both day and night. The crew at each sawmill usually consisted of two men – a sawmaster and a saw boy.

Many of the sawmills were initially small stream sawmills owned and operated by local farmers. During the 17th century, the industry was regulated by the authorities, and an upper quantity was set that should not be exceeded. Only these "quantum sawmills" had the right to produce for export, and by the latter half of the 18th century, almost all of these mills were owned by citizens from Bragernes and Strømsø. They also had the opportunity to concentrate production in larger units, for example by transferring quantities from the smaller mills. In this way, more and more of the sawmill production in the Drammensvassdraget was concentrated at Hønefossen at Ringerike and at Eiker, especially at the mills in Vestfossen and Skotselv.