House Framing

Cutting House Rafters

Category Construction Glossary
One of the most time consuming tasks in homebuilding can be the cutting of a roof.
In some cases it can take as long to cut and frame the roof as it does to frame the
rest of the house. It can also require a lot of space to get the job done. It is in ones
best interests to plan ahead during the course of construction to be ready when it
comes time to cut the roof.

Whether the roof be a simple gable roof or a complex roof with multiple hips and
valleys you want to be able to cut more than one rafter at a time. Sawhorses
become a valuable commodity during the roof cutting phase of construction.
Cutting a half dozen or more rafters is what you want to try for. To achieve this
there are a few options available to the roof cutter.

If you only have one set of horses, nail an eight foot 2x4 flatwise to the top of them.
This will allow you to mark and cut six or more rafters depending on their width.

The second option is to use two pair of sawhorses. Just like the previous option,
nail a 2x4 flatwise over the top of two horses. In this instance you are not limited to
an eight foot 2x4. You can use an 8, 10, 12, or even a 16' 2x4 depending on how
much room you have to work in.

The third option is to make your own sawhorses out of a 2x10. Put legs on it just
like a normal sawhorse. Again, your only limitation is what you have available for
length of 2x10 and how much room you have to work.

Another time saver is to make a rafter pattern. To do this, pick the straightest
piece if lumber you can find from the rafter material. Once you have determined
the length of your rafter from the plumb cut to the birdsmouth, the depth of the
birdsmouth, and the length of the rafter tail, transfer this information to the
material. After you have marked all of this on the 2x, carefully and accurately cut
the rafter. This is going to be your pattern for the rest of the rafters so you want to
be precise with your cuts.

The next move is to nail stops to the top of the pattern. Cut two pieces of plywood
about 6" long by 2 1/2" wide. Nail one to the top of the 2x about 2" from the plumb
cut, letting it hang over both edges of the 2x one half inch. Nail the other piece just
above the birdsmouth. You now have a pattern to mark the rest of your rafters
without having to measure each and every one of them.

When you are ready to start cutting the rafters, lay as many boards on the horse
as you can and have enough room for the saw to fit inbetween each one. When
laying the boards on the horses, have all the crowns pointing in the same direction
(When looking down a board while flat most boards are bowed one way or the
other. The convex side would be the crown). Take the pattern and lay it on top of
each board with the plywood stops resting on the crowned edge and mark them.

You are now ready to cut rafters. When making your cuts, cut the pencil line. Cut
the plumb cut first and then move to the birdsmouth and tail. Depending on how
many rafters you are cutting you may have to slide them back and forth so you are
not reaching over to far to make your cuts with the saw. When cutting the
birdsmouth it is okay to over cut it to totally remove the material.
Cutting Rafters