Timber Roof Truss Span Tables

View allowable load tables.

Timber roof truss span tables.

Timber frame truss and purlins. For pitched roofs flat roofs and ceiling joists. Stairwells rooflights and dormers attic trusses will provide living accommodation in the roof space. Support might be needed for very large spans.

Roof truss span tables alpine engineered products 15 top chord 2x4 2x6 2x6 2x4 2x6 2x6 2x4 2x6 2x6 2x4 2x6 2x6 bottom chord 2x4 2x4 2x6 2x4 2x4 2x6 2x4 2x4 2x6 2x4 2x4 2x6 2 12 24 24 33 27 27 37 31 31 43 33 33 46 2 5 12 29 29 39 33 33 45 37 38 52 39 40 55 3 12 34 34 46 37 39 53 40 44 60 43 46 64 3 5 12 39 39 53 41 44 61 44 50 65 47 52 70. Therefore care has to be. Finally the truss calculator will compute the best dimensional method to connect the pieces of the truss with steel joints and a bridge. Adding purlins between heavy timber trusses is an elegant way to reduce the cost of a timber frame roof because purlins permit an increased on center distance between trusses so you purchase fewer trusses.

An added benefit are the strong lines that purlins create by running parallel to the ridge beam s. Span tables span tables can be used to determine the size of a timber member of a particular strength class required for a given span. Member tables for seasoned timber stress grade f17. 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.

View size selection tables. The more complex the truss framework is the greater quantity of these joints will be required. Joists crippled over supports shall be considered as single span joists. Rafter or uss spacing w lintel span.

Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. The same thing is true for the bridge of the truss. They also tell you what the maximum spacing should be between each section or timber member size of joists mm clear span c16 joist m clear span c24 joist m 47 x 95 47 x 120 47 x 145 47 x 170 47 x 195 47 x. These steel joints are needed to support the overall truss.

Surveyors span tables for designing roof rafters. View joist rafter tables. Maximum span of lintel mm tile roof 240 x 35 2600 2100 1000. Spacing loadings to attic trusses are usually greater than normal trusses see page 4.

Simplified span tables for southern pine lumber and glued laminated timber glulam headers beams and girders. Floor joist span use this table to determine the maximum lengths of floor joists based on species of lumber joist spacing and joist size. 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.