Roof Truss Terminology

Ansi is the american national standards institute.

Roof truss terminology.

Ansi tpi 1 1 1995 is a publication of the truss plate institute tpi and ansi defining a standard for design and manufacture for metal plate connected wood trusses mpcwt. A gable roof has vertical planes usually on the. Typical framing systems gable. It is fixed to ends of battens purlins or verge rafters.

A roof s slope is the number of inches it rises for every 12 inches of horizontal run a roof with a 4 in 12 slope rises 4 inches for every 12 inches of horizontal run. The truss profi le span heel height overall height overhang. Trim along the edge of roofing at a gable end. Tension forces being exerted on a truss member that creates pulling apart or elongating effect.

The truss profile span heel height overall height overhang and web configuration depend on the specific design conditions and will vary by application. Pitched truss any truss in which the top chord is sloped and the bottom chord is horizontal. Truss terminology technical terms used in the truss industry may not be familiar. Roof trusses manufacturers terminology components of a truss apex peak.

The terms pitch and slope are simply two different ways of expressing the same measurement. Slopes at roof pitch. The part of a structural member that extends beyond its support see figure. The highest point on a truss.

A truss may also be so manufactured because of transportation considerations e g. Truss a pre built structural member capable of supporting a load over a given span. Bearing cut or seat cut. Flat truss a truss which has the top chord parallel to the bottom chord over the entire length of the truss.

Bottom chord bc or tie beam. Truss terms the terms below are typically used to describe the various parts of a metal plate connected wood truss. If the roof eave extends beyond the gable end wall by more than 1 then a dropped gable is normally used. Symmetrical a truss whose loading and configuration is exactly the same on both sides of the centerline.

Anchorage is the connection of the roof or floor truss to the building structure. The gable roof provides for the most basic of roof systems. The lower portion of a piggyback truss. The same roof has a 4 12 or 1 3 pitch.

A truss consists of one or more triangles in its construction. Some of the more common are listed below and are illustrated on pages 3 4.