First is the angle of the roof rafter. This MUSt be established BEFORE any cutting takes place.
Identify the wall plate (normally a 4 x 2 (2 x 4 if in the US)timber across the top of the wall of the building. The plate sits with the 4 inch face flat on the wall with the 2 in high side vertical to the wall.
Measure the horizontal cut, called the seat. Trace a horizontal line straight across the surface of the rafter or stable brick. This line marks where the top of the joist (or other brick) must meet flush with the rafter (or stable brick).Subtract the thickness of the wall. Measure the wall -- six inches, for example -- and subtract it from the length of the seat line. Dot this mark on the seat line.Then mark the plumb, or vertical, line. Align the measuring tape vertically with the dot on the seat line. Trace the vertical line, straight down to determine where the side of the joist (or other brick) meets flush in the rafter (or stable brick). Cut out the "bird's mouth" angle to fit in the frame.
with a saw.
If the plate height gets higher increase the depth of the birds mouth that sits on the plate. The birds mouth is the notch cut out of the rafter that allows it to sit flat on the top of the plate. If the plate is low then you will need to place a packer on top of the plate.
to eat, or to sing, or to vomit into the mouths of their children
A Jack rafter is a rafter that has the pitch of the roof cut onto one end with a 54 degree angle this sort of rafter is one of several that fit onto a hip ridge. To cripple a piece of timber means to cut it partway through in order to straighten it if this is done to a wall timber it will need to be splinted to restore the strength of the stud
Gaggle
The figures on the outer edge of the curve are degrees. Use these to set the angle/pitch of the roof. The figures on the inner edge of the curve are a ratio of the length of common rafter per foot or metre of run or span of roof. Take half the span of the roof in feet OR metres and multiply by the figure for the pitch of your roof this will give you the length of your rafter from birds mouth to the centre of the roof. Then make a deduction of half the thickness of the ridge board. at right angles to the bevel . The easiest way to use the bevels/angles from the square is to place the square on a piece of ply or board and mark all the bevels/angles onto the board and then use a sliding bevel/bevel square to apply the bevels/angles to the rafters and other members of the roof. No 1= Plumb & Seat cut for the Hip No 2=Plumb & Seatcut for Common Rafter No 3=Edge cut for the Hip (Mitre) No 4=Edge cut for Jack Rafter No 5=Side cut for Purlin No 4A=Edge cut for Purlin (Mitre) No 6 Lip cut to Purlin .This is the sloping cut which goes under the bottom edge of the Hip where the Purlin abutts to the Hip Rafter
Birds use their tongues to taste, they use their beaks/ mouths to drink.
Patrick Rafter's birth name is Patrick Michael Rafter.
You set the bevel on your saw to a 45 degree angle. Then set the angle on your saw base to the angle of your plumb cut.
Charles Rafter died in 1935.
Leonard Rafter was born in 1912.
Leonard Rafter died in 1964.