[Greenbuilding] protecting outdoor wooden structure from future decay (or at least delaying it)

[Koehn Chris]

Re: timber frame joinery susceptible to rot: this is correct, if the same techniques that are used inside are used outside. Historic examples (and smart contemporary ones) employ a few preventative measures:

• Slope mortises and tenons to drain
• Drill sloped drainage holes from the back of mortises to allow drainage and drying
• Put a penny in each mortise: the copper leaches an anti fungal into the joint over the years.
• Slope beam tops to allow for natural drainage
• Use species that are naturally rot resistant
• Keep post feet well up off of grade and avoid splash-back.

Wood can get wet; so long as it's allowed to dry to a moisture level that won't support the critters that cause rot, it can remain in outdoor service for many years.

Chris Koehn
TimberGuides
Vancouver Island