Verandah beams gl8 sheet roof 21 verandah beams gl8 tile roof 24 ridge beams f7 42mm sheet roof 25 ridge beams f7 42mm tile roof 28.
Roof load width verandah.
For sheet roofed houses with 900 mm rafter spacing in wind classification n4 or c2 the minimum size of f5 or mgp 10 rafters or top chords shall be 90 x 45 mm.
You would require three post to cover the 6 5 mtrs of beam length.
The size of the roofing material is needed to calculate how much load the roof members and substructure need to support and therefore what size the underlying timber parts need to be.
Sheet roof spacing mm rafter size 600 760 900 1000 1200 66 x 30 1250 1150 1050 1000 950 90 x 30 1650 1550 1550 1400 1300 138 x 30 2600 2300 2150 2000 1800 185 x 30 3000 2650 2450 2350.
This number represents the total load that your roof must carry.
The maximum overhang of house rafters or trusses shall not exceed 750 mm from outside of top plate to end of rafter truss.
Roof load width rlw and floor load width flw can be determined from as1684 or from the images below.
For any particular load the allowable span of patio cover joists and beams depends on wood species and board size.
For the pergola beams shown in illustration the roof load width is the dimension representing half the rafter span plus any rafter overhang.
If an example roof is 10 feet by 20 feet the total area is 200 square feet.
Use the drawing above to identify the relevant measurements for calculating rafter and verandah beam sizes.
Multiplied by 40 pounds per square foot equals 8 000 pounds.
This video explains all the details of calculating the roof load width rlw for a variety of roofing types.
For any species the allowable span generally increases as the joist or beam increases in size.
25 degree maximum pitch n3 single span no ceiling and roof load 25kg m2.
When you refer to a beam s allowable span what you re really describing is the allowable spacing between posts.
Pitching beams 23 common installation details 25 notches cuts and holes in beams bearers joists and rafters 26.
If you have single span rafters of 4 8 mtrs the roof load width is 2 4 mtrs.
Roof beams 20 verandah beams 22 garage roof.
Ns not suitable.
If you can source a beam of 6 5 mtrs long in one piece the size required would be 240 by 45 in f5 or f7 or mgp 10.
Refer to as1684 2 and 3 clause 2 6 4 for other configurations.
The roof load width is half of the rafter span.
