Timber selection

The use of pine logs was based on ease of supply and cost. Ideally the logs should have been sourced from a renewable source and of original quality (unprocessed).

In cordwood construction, it is important to choose woods that shrink and expand very little - wood species that are “light and airy”.

Since constructing the wall, we have discovered the timber logs contained CCA, and that:
"There is a growing body of scientific evidence that timber treated with CCA poses a danger to both humans and the environment. As a result, authorities around the world are imposing tighter restrictions on its manufacture, use and disposal. Of greatest concern is the seepage of arsenic, a known human carcinogen, onto the surfaces of CCA-treated timber from where it can be dislodged onto hands and washed off into nearby soil or surrounding water. Chromium is also a human carcinogen. However, there is a lack of health studies on the combined health impact of copper, chromium and arsenic."

 

References:

http://brightgreenresearchblog.wordpress.com

http://www.herinst.org/CCAtimber/whatis.html