Roof Rafter Detail

Determine how many rafters you ll need for the roof.

Roof rafter detail.

The typical spacing standards for residential and commercial buildings are about 1 to 2 foot. Roofs are framed in five basic designs. Framework of all roofs are called rafters. The most basic thing a roof cutter needs to know and understand is a rafter length is simply the hypotenuse of a right triangle and the er is the base of the triangle.

Cold roof insulation between rafters wnapor barrier on warm side below orw sheatiiing roofing roofing 2 x 8 sleepers notched for vent aligned wi rafters flashing over rooang fascia sheatiiing 2 x 4 sleepers aligned w rafters provide. They do for the roof what the joists do for the floor and what the studs do for the wall. The top ends of the rafters often meet at a ridge beam but may butt directly to another rafter to form a pair of rafters called a couple. Simple roofs such as a shed or the common gable are fairly easy to construct even without plans if you understand the basics and a little geometry.

A simple rafter roof consists of rafters that the rafter foot rest on horizontal wall plates on top of each wall. Rafters are inclined members spaced from 16 to 48 inches apart. Other roof protrustions sothat notiiing obstructs tiieflow ofair from eave to ridge. The function of each component is.

The ridge board is non load bearing and merely provides the point of connection for the opposing rafters and is only a nominal 1 thick. The app graphically shows the detail. Piece by piece rafter roof construction however is still the more common construction method for many buildings. With rafters it runs in perpendicular from the walls to the ridge while with purlins it runs to the ridge in parallel.

A rafter tie resists spreading of the building walls by bulges at the wall top that would otherwise occur due to roof loads. The tops of the inclined rafters are fastened in one of several ways determined by the type of roof. Rafter calculator mobile is accurate fast and offers an abundance of features makes life easier for everyone involved in a project for building a roof. Effective run is the run span 2 minus the ridge deduction usually the ridge board 2 and is the dim used to calculate the rafter length.

Rafters act more like the top chord of a roof truss than as a roof joist. Shed gable hip gambrel and mansard. Depending on how wide the home is you can divide the total length in feet by two to determine how many trusses will be needed. A rafter tie is a horizontal tension tie that is located in the lowermost third of the span of a pair of opposed sloped or gable roof rafters.

For most load bearing requirements a roof truss will need to be placed every two feet along the walls.