Roof Rafter Span Definition

Dead load weight of structure and fixed loads 15 lbs ft 2.

Roof rafter span definition.

Building with them is known as stick framing. In our sketch above the rafter run is shown as run under the left half of the roof. Live load is weight of furniture wind snow and more. Every piece is measured cut and fastened together to form the rafter.

Also available for the android os. The horizontal or level distance covered by the rafter the bottom chord or base of a right triangle. The upper rafters in a curb kerb gambrel mansard roof roof. The span would be 11 5 3 4.

This is the horizontal distance from the inside surface of the supporting wall to the inside surface of the ridge board. This means that each rafter is built on the job site using dimensional lumber. Rather the span is based on the rafter s horizontal projection. So consider a simple gable roof on a 24 foot wide ranch framed with 2x6 exterior walls and a 1 1 2 ridge.

2 are indicated below. 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. 1 psf lb f ft 2 47 88 n m 2. Definition of roof span.

The foot of a hip rafter lands on a dragon beam. Definition of rafter run. This is the horizontal distance from the inside surface of the supporting wall to the inside surface of the ridge board. Hip rafter angle rafter.

Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall. 1 ft 0 3048 m. The rafter in the corners of a hip roof. Live load 20 lbs ft 2 956 n m 2.

Span calculator for wood joists and rafters also available for the android os. In our sketch the rafter span is referred to as the rafter line length. The un supported length of the rafter along its slope the diagonal or hypotenuse of a right triangle. 1 the span of a rafter is not based on the measurement along its length.

Normally a roof span is the same as the building width between the outer edges of the wall top plates. In our sketch above the rafter run is shown as run under the left half of the roof. Use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size. The longest rafter on the side of a hip roof in line with the ridge.

Rafters are the traditional means of framing a roof. Rather the span is based on the rafter s horizontal projection. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. Rafter spans for southern yellow pine douglas fir and eastern spruce.