Hi Mo & Gabel,
I think that selecting poor quality stems for use in timber framing will in general result in more problems than its worth.
I have just started a project in Oxfordshire with the Oxfordshire Woodland Group and the Oxfordshire Buildings Record to examine old buldings with a view to producing a factual record of the typical sizes, species, quality and conversion methods employed in the construction of vernacular timber framed buildings. I want to be able to determine typically how woodlands were managed in medieval times when the demands placed on the woodland were probably much higher than today.
The answer to your question might lie more in answering the general question "how long have you got?". My own woodlot has 60 year old Dougls Fir growing in it and my intention is to start selectively culling these trees and encourage their replacement by broadleaf oak, ash, cherry, elm etc but this of necessity will be a slow process in order to help prevent blow down of the remaining trees. Adopting a "Continuous Cover Forestry" policy will probably provide a reasonable balance between addressing woodland management issues and timber framing requirements. I have started this process in a small way but frankly will look more to my son to implement this plan over his lifetime and beyond.
Sometimes I cycle past old "stored coppice" woodlands and marvel at the "fit for purpose" timber quality that this type of woodland is capable of producing on a regular basis but these woodlots no longer appear to be worked traditionally and so are reverting to high forest with much larger stem sizes than needed for timber framing.
This is a very complex topic to address within a few short lines with answers quite variable depending on geographic location.
Regards
Ken Hume
