Timber Roof Joists

Floor joist span use this table to determine the maximum lengths of floor joists based on species of lumber joist spacing and joist size.

Timber roof joists.

These span tables apply only to flat roof and roof with a slope of up to 10 degrees. The choice depends on the load bearing requirement which is strongly influenced by the length of the span that the beam must bridge. The important point to keep in mind when you use your truss calculator is that every truss calculation is completely unique and is based on the size of your roof and its specific dimensions. Usually 400 450 or 600mm but any value can be used up to 610mm max usually 400 450 or 600mm but any value can be used up to 610mm max 1 2 timber strength class and joist size.

Rafters have a tendency to flatten under gravity thrusting outwards on the walls. They are nominally 2 inches thick actual width usually 1 1 2 inches and come in a variety of widths from 8 to 12 inches. Notches are not to exceed 0 125 of the depth of the joist and are to be located between 0 07 and 0 25 of the span from the support. Sawn carcassing timber cls studwork timber carcassing timber batten fencing timber joists.

Joists are traditionally made from timber. Span tables for flat roof joists to bs 5268 7 2 imposed loads of 0 75 kn m for maintenance and snow load are applicable where there is no permanent access no fixed ladder or staircase and most areas where the altitude does not exceed 100 metres refer to bs 6399 3. Sheet materials mdf hardboard. Our selection includes treated carcassing to prevent wood deterioration even in damp conditions as well as untreated and premium varieties.

Roof rafter span use this table to determine the maximum lengths of roof rafters based on species and grade of lumber spacing dimensions load and slope. This is the distance between joist centres. The truss is a framework consisting of rafters posts and struts which supports your roof. Timber to be covered these span tables do not apply to timber which is fully exposed to the elements.

Mouldings planed timber planed timber mouldings skirting cladding wood flooring window boards. A timber roof truss is a structural framework of timbers designed to bridge the space above a room and to provide support for a roof trusses usually occur at regular intervals linked by longitudinal timbers such as purlins the space between each truss is known as a bay. As the name trimjoist indicates our product can be trimmed on the construction site for a custom fit. Roofing roofing timber roof sheets flat roofing roof windows fascia soffit guttering view all.