Top Chord Of Roof

The end depth is the distance between the top chord and the bottom chord or the projection of the bottom chord near the center line of the support.

Top chord of roof. The chord s length must match the width of the roof. Calculate rafter length of roof by doing the following. When the 4x4 block length is extended this is referred to as mid chord bearing. This truss can be used when greater area is needed for solar panels on one side of a roof or if the building owner wants to put windows in the vertical portion.

We will use gussets made from 3 4 plywood and shot with 2 3 8 ring shank nails. A combination of the two is a truncated truss used in hip roof construction. Dead load weight of roof trusses top chord bottom chord webs weight per lineal foot plf 2x4 2x4 2x4 4 3 2x4 2x8 2x4 5 6 2x6 2x4 2x4 4 8 2x6 2x6 2x4 5 5 2x6 2x6 2x6 6 2 2x6 2x8 2x4 5 9 2x6 2x10 2x4 6 6 2x6 2x10 2x6 7 2 2x8 2x8 2x4 6 6 2x8 2x8 2x6 7 2 2x8 2x10 2x8 8 4 dead load weight of floor trusses depth in inches top chord bottom chord. The ideal way to position the breaks is to match them up with the webbing.

Clerestory trusses can be used when an extension of a top chord plane is desired over the peak of a common truss to create greater surface area on one side of the roof than the other. A free calculator is provided at the bottom. Difference in slope between the top and bottom chords is at least 3 12 or the bottom chord pitch is no more than half the top chord pitch. The chord size and web configuration are determined by span load and spacing.

First find the length of the bottom chord and divide by 2 multiply it by itself example if it is 10 ft multiply 10 x 10 equals 100. A minimum end depth of 12 must be provided in all cases with 18 minimum end depth in most cases and for. The top members of a truss are known generically as the top chord bottom members as the bottom chord and the interior members as webs in historic carpentry the top chords are often called rafters and the bottom chord is often referred to as a tie beam there are two main types of timber roof trusses. Top chordthe continuous 4x2 member forming the top of the floor truss.

Flat the most economical flat truss for a roof is provided when the depth of the truss in inches is approximately equal to 7 of the span in inches. The top chord or chords are the single most important elements of a roof truss. There are three ways that the tcll can be specified construction snow or combination of construction and snow. The top chord live load tcll that can be used in the design of a roof truss can depend on a number of factors.

Top chord bearinga floor truss support condition in which the truss load is transferred to the bearing or support through the top chord and 4x4 block end detail. It is often used for floor construction. Each of these affects the design in different ways. Closed in which the bottom chord is horizontal and at the foot of the truss and open in.