Civil Engineering Reference
In-Depth Information
inspector as he was merely responding to the situation with his understanding of the
normal skill level of today's tradespeople.
Stick framing a roof is still a viable option
If you are considering stick framing of your roof do not be swayed by the public opinion
that this is no longer realistic. All building is extremely rational. It is all about cause and
effect. If weight is applied to the top of a roof it must be transferred to the foundations. It
is simply a matter of having a consultant who understands the structural issues associated
with general building and can advise you, and is available to answer your questions as you
go about the process. Do not be daunted by the total job. The timber specification
schedule will give you details of what size timber is to be used where and your consultant
will help you work out the angles the timber is to be cut at, and how to fix it in place. The
rest is simply one cut and one nail at a time. This reminds me of the old riddle, 'How do
you eat an elephant?': the answer is simple - 'One mouthful at a time.' Although you might
need a big freezer to keep it in until you get to the last mouthful, I guess your building
consultant could be compared to a freezer, but I trust that you can find a consultant with a
little personality and warmth rather than a cold fish, or elephant should I say.
Stick framed roofs
Template for cutting rafters
The template will give you a pattern for the top and bottom cuts required for rafters.
When the rafters are supported at the top by a beam or wall, you may choose to rest the
rafters on the beam with the rafters from opposite sides of the building fixed beside each
other rather than butt join them together. If this is the case you will not need the pattern
for the top cuts on the rafters, however, as you
will soon discover, the angle of this cut is
required to establish the bottom cuts or notch
for the rafters.
The top of the rafter is to be cut at an
angle that allows the rafter to sit evenly onto
the face of the ridge beam. This cut is known
as the plumb cut. At the bottom of the rafter a
'V' shaped cut will be made to allow the rafter
to sit on the outside wall with the tail of the
rafter overhanging the wall thereby creating
an eave. The bottom cut on the rafter is
known as the birdsmouth. Each rafter will
have to be marked individually for these cuts
so it is best to have a pattern for both cuts.
The template for these cuts is known as a
roofing boat (see Figure 8.12).
The pitch of the roof will determine the
angle of the plumb cut and birdsmouth.
8.12
Roofing boat used to mark timber to be cut for
rafters
