Framing--the Backbone of your Log Cabin
Framing is the structural skeleton of your house. The drawing at
the top indicates the important framing members of any of the
cottages. The most important elements are the sill, header,
joists, girders, sole, flooring, studs, plate, and rafters.
Let's take a look at these parts.
Except in the case of concrete slab construction, the sill is
the first wood member to rest on the foundations and will be the
first wood member you will put down. The sill is usually a
2-by-4-inch piece. In pier construction you will note that I
have occasionally used a 2-by-6-inch member. This is because the
header is made up of two pieces 2 inches thick, instead of one,
as shown in the illustration.
Sills form a bearing surface for the undersides of joists. They
should be bolted to the slab or wall foundations. If you are
using pier foundations, it is important that you first put down
the sill around the building, then spike the inner header to the
sill from the underside. After this is done, lay out the joists
and securely spike the inner header to them.
At the corners, stagger these two parts. Then spike the outer
header to the inner one, overlapping at the staggered corner
edge. What you have done is to build a girder with a resting
place for the joists.
Headers, except as noted above, are usually 2 inches thick and
the same width as the joists. They run around the outside
perimeter of the building and help keep the joists in a vertical
position. They also help to transmit the roof and wall loads to
the foundation.
The notched joist arrangement is used when no sill is provided.
The blocking provides a bearing spot for the joists. If you use
pier foundations, be sure to follow the sectional drawings for
each cottage, because this header may actually be a girder
around the outside of the building.
Also be sure that the joists are securely spiked to the header.
Try, as far as possible, to make the headers of one continuous
piece of material. If this isn't possible, be sure to join the
pieces over the center line of one of the piers.
Joists members are what your flooring will rest on. The sizes
applicable to each building are shown in the sectional and plan
drawings. In most cases they are 2-by-6-Inch members laid 16
inches on center. I have tried to design all the camps so that
it will not be necessary to cut most of the joists.
They are standard lengths which you can purchase from your local
lumberyard. Because the joint spans are short, it isn't
necessary to bridge the members. However, if you want a really
good job, put l-by-3-inch pieces of lumber between joists as
shown in the sketch at the side. You can also buy metal bridging
if you would rather use it.
Bridging is usually done every 8 feet along the length of the
joist. The floor joists are typically designed to take a uniform
load of 40 pounds. The fiber stress (f) is 900 or over. Don't
worry your head about these figures.
What it means to you is that you should use Douglas fir (Coast
Region or Inland Empire), West Coast hemlock, Western larch,
Southern yellow pine, redwood, oak, or any other wood having the
necessary characteristics. Most yards carry either Douglas fir
or hemlock for framing purposes.
Jack Hudson is a freelance writer for
http://www.log-cabin-plans-n-kits.com , a site that serves as a
resouce for the planning and building of log cabins. His
articles have also been featured on home related sites such as
http://www.best-house-n-home-plans.com/ as well as
http://www.garage-plans-n-kits.com/
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