Monday 7 November 2016

Choosing House Logs is a Serious Business

Many considerations go into choosing the right wood for a log home....or choosing the right home plan for the wood that is available to you...

Kanga-Doodle picks house logs: click for video
Choosing house logs is a serious business; it goes without saying that the wood must be sound and of a suitable size for both the plan and the geographic location of the building (insulative value of the wood species and compliance with the new energy code as well as local building code.)
People often wonder which species of wood is preferable for timber and log homes - the answer to that varies;  locally available wood is often the best choice - for example - if building in North Carolina or Ontario using a local log builder, the home will likely be built using Eastern White Pine.
Lodge pole pine is also an option for many Northern log builders accross the continent.

Here in south central British Columbia we have a wider range of log species to work with including Engelman spruce, Western red cedar, Douglas fir and Alaska yellow cedar.

My personal preference for house logs are Western red cedar, Doug fir and Alaska yellow cedar, so a customer (local or from far afield) who has chosen a BC log builder to work with has quite a few more options.

Early on we favoured Engleman spruce - primarily because our Japanese market had a preference for it's pale sap wood. Spruce was also easy to access and easy to peel, but on the down-side, we struggled with how spruce checks (or cracks) as it dries (typically one LARGE check running the length of the log) and spiral grain twist is also more pronounced in spruce, thus narrowing the selection of wood that met our specifications.

Douglas fir, while a brute to peel, is a more stable wood. Checks tend to occur frequently around the circumference of the log, but barring radical spiral checks are quite regular and narrow. Douglas fir is stronger than spruce and is a better log for load bearing.

The insulative values of Western red cedar surpasses both fir and spruce, so is an ideal wall log. Cedar tends to be less mobile as it dries and also shrinks less. (One drawback with Western red cedar are it's load bearing qualities - in roof systems the required size of a cedar log would often be out of scale with the wall structure, which is why we generally use Doug fir for the roof system. The warm reddish tones of both are very similar, so the variation of species is vitually unnoticeable.

Alaska yellow cedar (also known as Cypress) can be difficult to source, given that the calibre of wood we require is highly prized by the Japansese temple market,  however we have been fortunate to secure a source of Alaska yellow cedar and offer it as an option to our customers.

Douglas fir is the most economical of the species that we build with, but some styles of structures - such as dovetail log homes -  I prefer to build using cedar. Round post and beam log homes require very large diameter wood - averaging 18 to inches in diameter for the posts. Any of the species that we build with are suitable for post and beam as long as the diameter is met. Square post and beam requires that we start with wood of at least 20 inches in average diameter, and our scribed log homes are built with a minimum diameter of  14 inches at the top of the log. Timber frame homes offer more latitude in wood size, as they are typically wrapped from the outside using either SIP's (Structural Insualted Panels) or conventional framing and insulation.

Wood shrinks as it dries and while log homes can be successfully built using green wood, we prefer to use drier material.  Regardless of the species we are building with, we insist or wood that is either air-dried (under 19% moisture content) or kiln dried.

So which species of wood should you choose for your log home? The above really just scratches the surface of house log selection - so please feel free to contact me for more in depth information on this topic - or watch our video featuring the Nicola LogWorks mascott: Kanga-Doodle as she demonsrates her log selection style...