Rafters are the traditional means of framing a roof.
Roof rafter span definition.
Use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size.
Building with them is known as stick framing.
Live load 20 lbs ft 2 956 n m 2.
The rafter in the corners of a hip roof.
1 in 25 4 mm.
The upper rafters in a curb kerb gambrel mansard roof roof.
Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run.
In our sketch above the rafter run is shown as run under the left half of the roof.
The longest rafter on the side of a hip roof in line with the ridge.
Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no.
So consider a simple gable roof on a 24 foot wide ranch framed with 2x6 exterior walls and a 1 1 2 ridge.
The un supported length of the rafter along its slope the diagonal or hypotenuse of a right triangle.
Every piece is measured cut and fastened together to form the rafter.
Rather the span is based on the rafter s horizontal projection.
This is the horizontal distance from the inside surface of the supporting wall to the inside surface of the ridge board.
Normally a roof span is the same as the building width between the outer edges of the wall top plates.
Span calculator for wood joists and rafters also available for the android os.
2 are indicated below.
Dead load weight of structure and fixed loads 15 lbs ft 2.
Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall.
Also available for the android os.
1 the span of a rafter is not based on the measurement along its length.
Hip rafter angle rafter.
Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch.
Definition of rafter run.
Rafter spans for southern yellow pine douglas fir and eastern spruce.
In our sketch the rafter span is referred to as the rafter line length.
The foot of a hip rafter lands on a dragon beam.
This means that each rafter is built on the job site using dimensional lumber.
In our sketch above the rafter run is shown as run under the left half of the roof.
This is the horizontal distance from the inside surface of the supporting wall to the inside surface of the ridge board.
The span would be 11 5 3 4.
Definition of rafter span.
Definition of roof span.
The horizontal or level distance covered by the rafter the bottom chord or base of a right triangle.
Rather the span is based on the rafter s horizontal projection.
