Timber Roof Truss Span Tables

Other more complex load condition spans can be determined with our free hyne timber design 7 5 software.

Timber roof truss span tables.

For simple construction such as domestic construction this can be determined from span table supplements in as1684 2 and as1684 3. View allowable load tables. Technical diagram span tables f7 rafters on page 35 30mm m aximum allow able sp ans mm sheet roof spacing mm rafter size 600 760 900 1000 1200 66 x 30 1250 1150 1050 1000 950 90 x 30 1650. 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.

Construction details should be in accordance with as1684 2. Required size for a given span. Trusses must be designed for any special loading such as concentrated loads. Top chord dead load 10 psf.

Timber frame truss and purlins. Roof load width rlw and floor load width flw can be determined from as1684 or from the images below. Span tables allow users to choose an appropriate size and stress grade to achieve spanning needs. A maximum roof pitch of 25 degrees is assumed.

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

Spacing should be interpreted as the centre to centre distance between adjacent parallel members. 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. 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. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters.

View joist rafter tables.