Roof Truss Design Basics

Bowstring pitched and flat.

Roof truss design basics.

Common truss configurations for the most widely designed roof shapes. Mono used where the roof is required to slope only in one direction. Size the bottom chord 0 25 inches 0 64 cm longer than the floor. Scissors provides a cathedral or vaulted ceiling.

Start by noting the exact length of the. It s often used for sheds garages or extension of an existing roof. If roof slopes are not provided i e if the roofs are flat then it may be very difficult to provide sheet roofing without the use of effective mastic sealing of the sheet joints. A mono truss roof allows for more sunlight and visual space proper drainage and relatively cheaper.

Slope for roof is necessary to drain off rain water falling on the roof. Architectural style types of roofing material methods of support of column framing and relative economy are the principal factors influencing a choice among the three basic types of trusses. A mono truss is a one sloped truss that forms a right angle triangle. The very first step for building roof trusses is to prepare a design layout that can be sketched by a professional architect or can also be done by using a software that is specifically meant to design a roof truss.

Designs 1 3. Incorporate overhanging top chords to add extra visual flair. Residential roof trusses as shown in figure a are an engineered configuration of wood members placed to hold the weight of the roof s finishing materials the internal structure s ceiling and any snow load that may occur. Cut plywood gusset plates to fasten.

On some roof trusses the 2 top chords extend down over. The truss is a framework consisting of rafters posts and struts which supports your roof. A truss frame consists of a roof truss and a floor truss joined by exterior wall studs. In addition side and end wall height and type roof shape and bracing requirements must be considered.

The pitch of the truss is an important factor in the selection of a truss. Also in pairs with their high ends abutting on extremely long spans with a support underneath the high end. The basic design procedure is described in this section in terms of engineering design methodology architectural design examples and design variations. As we will see below there are several different types of designs and this will impact the angles and designs of the overall truss.