the frame is raised, there are a variety of enclosure systems
that can be used to complete the construction of the walls. Our
designers at Northwest Timber Frames can be of great assistance
in helping you decide which system works best for your particular
most popular method in the industry are Structural Insulated
Panels (SIPs), which can be installed to provide not only the
exerior walls but sometimes the roof/ceiling systems too. SIPs are made of Expanded
Polystyrene (ESP) sandwiched by two sheets of plywood-like material
called oriented strand board (OSB). Invented in 1935 at the Forest
Products Laboratory in Wisconsin, SIPs originally were composed
of regular plywood and standard framing members and filled with
standard insulation. Over a 30 year period the design changed
as new materials were brought to the market place, including
rigid insulation in the 1960s.
computer aided production became possible and today's SIPs are
mass produced with amazing accuracy and come in wall thicknesses
from four to six inches and up to 14 inches for ceilings. They
can even be cut in curves for specific applications. SIPs are
widely used because of their speed of assembly and their energy
efficiency. Once the panels or other wall enclosure systems are
complete and in place, the roof and siding can be added to make
the house weather tight and the interior work can begin.
should be noted that SIPs also come with a straw mixture replacing
the rigid insulation. The disadvantage of these types of SIPs
is they weigh considerably more than rigid insulation panels,
which considerably raises the cost of shipping.
enclosure options include conventional framing methods using
standard batts or blown in cellulose insulation as well as natural
insulating materials such as straw bales, clay, wood chips or
clay and wood chips combined with straw. The advantage of straw/light
clay is that you can increase the insulating factor by simply
increasing the width of the wall, according to the demands of
chips mixed with clay can also create a fire resistant and insulation
efficient wall similar to straw and clay. The labor to produce
the mixture and to infill the walls, however, is about half that
of straw and clay. In wood producing regions, wood chips could
become an attractive option. Other infill options include: straw/clay
blocks, reed matting, wood chips and cellulose fibers.
roof systems to consider are thatching, where reeds or other
materials are woven into bundles and attached to the roof; and
the use of natural slate shingles.
methods you decide to use in your construction project Northwest
Timber Frames will be able to help facilitate it.