Roof type chart 1.
Traditional roof framing.
It s steep pointed roof which extends all the way to the ground.
Truss a network of pre made usually double sloped beams connected or bridged by a bottom beam or brace.
There are several variables to consider when determining the proper rafter size.
The other part of the.
Start with a layout of a rectangular shape building.
This sizing guide for roof rafters will help determine what you need for your small project.
Add the length of the overhang beyond this mark and.
The bonnet roof is identified with the extending ledge around the base of the roof.
The a frame is very easy to identify.
1 8 pitch is given so 24 x 1 8 equals 3 or unit of rise in inches.
Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter.
Line length is the hyptenuse of the triangle whose.
Measure form the top of this line down the board to determine the line length or length of the rafter less the ridge.
Locate a centerline at the middle section.
Depending on the roof design and the roof rafter spacing.
Figure 2 2 roof framing terms.
Draw a ridge line between the intersection points of the hip rafters.
However you should be very careful while doing this as one wrong cut can compromise the strength of the truss.
In terms of roof covering standing seam metal roof would be the best option in terms of strength and durability but you could also go with architectural shingles light color roof.
The best roof shape for a high wind area would be a hip roof but it s more expensive to construct than a traditional gable roof a common roof for sheds.
Rafters are the traditional method for supporting a roof.
If the unit of rise in inches is 3 then the cut is the unit of rise and the unit of run 12 inches or 3 12.
Joints on a traditional roof truss frame are mostly held together by metal plates or solid wood pegs.
Building codes such as the icc s 2012 international building code section 2308 10 roof and ceiling framing typically specify that where rafter ties are used they are required at intervals ranging from 12 to 24 o c.
With this type of roof truss it is possible to add as many webs as you want to the centre of the truss.
Position the square at the end of the rafter board with the tongue on your left and facing away from you.
This allows the carpenter to layout complex cuts from 2 dimensional plans that represent the true shape of the rafter or timber framing joint.
The traditional roof framing geometry used by the french and germans carpenters of the past represents the timber in three dimensional visualizations stereotomy.
