There has always been a lot of driftwood that came to Iceland.
It floats into the sea from the main rivers of Siberia and is taken by the polar currents.
Captured in the ice, it drifts until it reachs the coasts of Iceland.
Siberian driftwood is the main component, but driftwood from South America also reaches the coasts of Iceland.
The driftwood is filled with salt, because of its very long journey through the seas,.
Therefore, it is well preserved and suitable for the use of building houses.
The wood is so strong that it is still found in some of the oldest buildings in Iceland.
In this almost tree-less country, the driftwood was a bounty for the people in the old days.
Many people were able to survive the harsh winters because of the driftwood, especially in the north western part of Iceland.
The driftwood was not only used for building ships and houses but also for furniture, fences, fire and charcoal.
The oldest known driftwood was (after counting the year rings) five hundred years old.
It has been found that driftwood can take from five up to forty years before it reaches Icelandic coasts because it is stuck in the ice for many years.
Reference: http://www.jonadolf.com/Driftwood%20info.htm