Thursday, October 18, 2012

3 Advantages of This Cabin Design

Cabin perspective with carbonized siding.

Despite having a Ph.D. in architecture, I have much to learn about materials and construction.

Research skills and design skills are very different from construction skills, and craftsmen like traditional carpenters and masons understand material very differently from how designers understand materials.  The direct knowledge of crafting material with hand tools is very different from calculating building loads, and analysing circulation patterns.

With the acknowledgement of lack of experience in construction, I have designed a cabin that I can build myself without the employment of contractors or heavy machinery.  Material cost needs to be low, as well skill level expectations.  I have never constructed a wooden truss, and it would take more than one attempt to craft one whose joints met building standards.  Instead the cabin design will carry loads vertically, and not rely on a truss.  

During the process of building I will certainly learn a great deal about material, specifically wood, and my design will allow me to learn while sharing my journey with readers of this blog.  It will be a lengthy process, but I am determined to share the construction journey with images and description.  Perhaps others can learn from my efforts as well.

The advantages of the cabin design are:
  • It can be built by hand.
I do not need heavy equipment, or skilled labourers.  I can mill timber, and process all lumber myself, if I have a saw mill and table saw.  The cabin framing does not support load, so my lack of carpentry skills will not affect structural rigidity.  All carpentry joints are simple, and do not require years of practice and experience.  I can dig and raise the foundation poles by hand, as well as mix and pour the small amount of concrete necessary for the foundation.  I can connect the timber with spike grids, lag bolts, joist hangers, and nails, again no special skills needed.   While roofing, siding, flooring, windows, and doors will take the most time, the are all architectural elements that can be built by hand.  

I will not be able to build glazing, plumbing fixtures, electrical fixtures, treated foundation poles, or timber hardware.  These things I will have to purchase.
  • It will have a pole foundation.
Pole foundations and framing are simple, economic, and strong.  Each pole serves as foundation, and as a framing member.  Pressure treated poles are buried at a depth of six feet, depending on soil type, and deliver all lateral forces directly into the ground.  The poles retain their original tree shape, and are stronger than dimensioned lumber, whose external tree fibres have been removed.  Trees grow a natural structural rigidity, and poles take advantage of that strength.  The poles are distributed in a twenty foot by forty foot grid, where all force from the roof rafters is delivered straight through the poles to the ground, instead of laterally with the assistance of a roof truss system.  Outside the cabin are most of the poles placed so as to not be in the way of siding and interior finish.  Furthermore odour and preservatives are kept outside the housing envelope.  The grade five poles range in size from six inch to ten inch in diameter.
  • It will have carbonized siding.
The tentative pattern for the siding is board and batten because sheathing is not required.  If I decide to use sheathing, I will craft it using tongue and groove boards, then I could choose another pattern, like bevel siding.  Another option is to use plywood as sheathing, instead of tongue and groove, because it does a good job at stopping air infiltration.  A fourth option is to use a foam-backed sheathing panel to increase insulation.  I have not decided on sheathing yet, but siding is fixed to siding girts, which are then fixed to the poles.  The wood siding, regardless of pattern, will be carbonized.  This means it is charred with fire, then a light oil applied to produce a near maintenance free siding that could last up to eighty years.  The process is simple, and could be produced by hand.

There are many things to be determined in the future, like stairs, and loft railing, but these considerations will certainly influence future design changes.  With these three advantages I should be able to accomplish my goal of building my own house.

Do you have any ideas that you would like to share?  What do you think about my cabin design?  Share your thoughts in the comments.