Timber Roof Beam Sizes

Rafter to ridge beam connection framing roof ceiling construction structural ridge beam absolute deflection in a ridge beam structural ridge beam tricks of the trade.

Timber roof beam sizes.

Usually 400 450 or 600mm but any value can be used up to 610mm max 1 2 timber strength class and joist size automatically calculate sizes suitable for supporting the loads below. Our heavy timber beams are cut to standard dimensions. Stress grades and timber sizes combine to determine the spanning ability of load carrying members. Beams of more than one ply must be fastened together with either nails or bolts.

Roof pitch between 30 and 45 degrees strength class c16 size of purlins in mm maximum clear span 1 5m maximum clear span 1 8m maximum clear span 2 1m maximum clear span 2 4m maximum clear span 2 7m. Tiled roof with ceiling 75 timber floor with floor boards 40 tiled or heavy floors 95 live loads kg m kg m floor domestic 200. For the initial calculation f can be estimated at 1 000. Starting from scratch with no previous knowledge of structures required.

A 8x12 beam will net an overall 7 x 11. This is the distance between joist centres. For simple construction such as domestic construction this can be determined from span table supplements in as1684 2 and as1684 3. L stands for the span of the beam in feet.

This span table is to the format and methodology given in bs 5268 7 2. Staggered pattern with at least a 3 x 120 nail. Here s how to calculate the size of a timber beam you need to span a given distance. The 2012 irc code calls for a minimum of a 32 o c.

Versa lam lvl size chart laminated beam span tables charts. We have learned from our experience to use at least a 3 1 4 x 131 groove shank nail in a column of four every foot apart down the laminate. Beam spans for roofs 2yamaha. These spans were calculated using our flat roof joist calculation.

Span tables allow users to choose an appropriate size and stress grade to achieve spanning needs. Per wwpa guidelines for standard dimension timbers a nominal 4 x6 timber nets to 3 x5 actual dimensions after it has been sawn all beams larger than 8 inch will mill to the inch. Fill in the parts of the formula that are already known. F stands for the beam s fiber strength in bending which depends on the species of wood.

In the example the beam spans the 10 foot width of the roof. The total load is 4 000 pounds. Beam sizes and properties beam size bxd nominal section area 10 mm 35x70 2 45 35x90 3 15 35x120 4 2 35x140 4 9 35x190 6 65 45x90 4 05 45x140 6 3.