Roof Truss Load Path

Design loads the building dead load is the only known load.

Roof truss load path. I for sloping or flat roof with slopes up to and including 10 degrees. All other forces will vary in magnitude duration and location. If one part of the load path fails or is discontinuous building failure may occur. Load path loads on the roof are initially supported by the sheathing.

910 pounds per lineal foot. Per ansi tpi 1 2014 section 7 5 2 1 figure 4 all loads being applied from roof trusses to wall and wall to ribbon board are considered to be applied as uniform plf loads. The irc does not provide specific guidance as to when blocking may be required to transfer the loads directly. Truss spanning between bearing walls.

The roof rafters transfer the loads to the ceiling joists and to the bearing walls that support the trusses. A when access is provided 1500 n m 2 b when access is not provided 750 n m 2 except for maintenance ii sloping roof with slope greater than 10 degrees. The building is designed for design load possibilities that may never occur. It is important to list live load dead load and total load separately because live load is used to compute stiffness and total load is used to calculate strength.

15 psf x 14ft 210 pounds per lineal foot. The truss could be designed based on the assumption that the 25 psf roof snow load is a factored ground snow load in which case a ground snow load is back calculated using asce 7 based on the specified roof snow load pg 25 psf therein lies the problem with specifying only a roof snow load. This allows wind uplift forces on the roof to be safely distributed through the walls to the foundation. A primary goal for buildings subjected to high winds is to maintain a continuous load path from the roof to the foundation.

Live loads on roof trusses. The live load shall be taken as follows. 50 psf x 14ft 700 pounds per lineal foot. R roof live load w wind load s snow load e earthquake load r rain load.

Roof truss span tables alpine engineered products 15. To transfer loads from the wall above to the truss ends where they can be transferred to the wall below. Total load psf duration factor live load psf roof type 55 1 15 40 snow shingle 55 1 15 30 snow tile 47 30 snow 40 20 snow 1 25 20 construction or rain not snow load 55 1 15 40 snow 47 1 15 30 snow 40 1 15 20 snow 40 1 25 20 rain or constn.