Traditional Roof Framing

There are several variables to consider when determining the proper rafter size.

Traditional roof framing. Draw a ridge line between the intersection points of the hip rafters. Figure 2 2 roof framing terms. 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. Joints on a traditional roof truss frame are mostly held together by metal plates or solid wood pegs.

The bonnet roof is identified with the extending ledge around the base of the roof. 1 8 pitch is given so 24 x 1 8 equals 3 or unit of rise in inches. Rafters are the traditional method for supporting a roof. Locate a centerline at the middle section.

The traditional roof framing geometry used by the french and germans carpenters of the past represents the timber in three dimensional visualizations stereotomy. Start with a layout of a rectangular shape building. 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. Truss a network of pre made usually double sloped beams connected or bridged by a bottom beam or brace.

However you should be very careful while doing this as one wrong cut can compromise the strength of the truss. Now draw a 45 degree line from each corner toward the centerline that can help to establish location specifications for. The other part of the. Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter.

Position the square at the end of the rafter board with the tongue on your left and facing away from you. Add the length of the overhang beyond this mark and. This allows the carpenter to layout complex cuts from 2 dimensional plans that represent the true shape of the rafter or timber framing joint. Rafter not pictured a supporting beam usually wooden that attaches to the peak of a roof and descends to an outer wall.

Line length is the hyptenuse of the triangle whose. This sizing guide for roof rafters will help determine what you need for your small project. Depending on the roof design and the roof rafter spacing. Roof type chart 1.

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. With this type of roof truss it is possible to add as many webs as you want to the centre of the truss. It s steep pointed roof which extends all the way to the ground. Measure form the top of this line down the board to determine the line length or length of the rafter less the ridge.