Flat Roof Steel Truss Span Tables

You can use sbca s span charts to roughly determine truss sizes available.

Flat roof steel truss span tables. In areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot. The figures are based on quality materials. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. The tables below give maximum spans for rafters and beams.

Posts these span tables are designed for a minimum post size of 50 x 50 x 2 5mm up to a maximum height of 3 0m. 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. Table 9 1 in span tables for joists and rafters figure 5 gives a required compression value of 237 psi for a span of 16 feet and bearing length of 1 5 inches. Roof pitch use recommended minimum roof pitches as specified by roof sheet supplier.

The same thing is true for the bridge of the truss. Flat roof span tables allow for a maximum roof pitch of 5º. 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. Roof truss span chart.

Finally the truss calculator will compute the best dimensional method to connect the pieces of the truss with steel joints and a bridge. Metal plate connected wood trusses hib 91 by permission of truss plate institute inc. These steel joints are needed to support the overall truss. The load span tables shown below demonstrate only a tiny subset of the possible combinations available with trussteel cfs roof trusses.

Intermediate bearing simple span trusses header beam pocket floor truss supporting header beam. Included are a series of representative roof truss span tables that will give you an idea of the truss spans available for a particular load condition load duration lumber type and truss configuration. Keep in mind that these tables are for estimations only. 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.

Roof floor truss manual 7 31 08 10 43 am page 11. The more complex the truss framework is the greater quantity of these joints will be required. The tables permit a bearing length of up to 3 5 inches but since 1 5 is probably the worst case that you ll encounter for joist or rafter bearing it s a safe value.