How far can rafters span NZ?
3.000 m
Step 1 – Rafter spacing The rafter span is 3.000 m, and because this is a light roof, the far right column of NZS 3604:2011 Table 10.1 Rafters for all wind zones (see Figure 2) can be used for rafter spacings at 1200 mm (see Note 4 in Table 10.1).
What Centres should rafters be?
Trussed rafters should be: evenly spaced at maximum 600mm centres.
How far apart should 2×4 rafters be?
A 2×4 can span a maximum of 6′ 7” when spaced 16” apart and used as a floor or deck joist. When used as a ceiling joist or a roof rafter, a 2×4 can span up to 7′ 3” spaced at 16”, and 6′ 4” when spaced 24” apart.
How far apart are ceiling joists NZ?
600mm centres
Joists shall be spaced at 600mm centres maximum and shall have a depth of 150mm minimum. Alternative Floor Framing: Use either Hyspan® or Hybeam® HJ series joists designed for strength and serviceability, no less than 150mm deep and spaced at no more than 600mm.
Can I use 4×2 for rafters?
You can use either 2×6 or 2×4 rafters for roofs with a 3/12 pitch or greater, but it depends on the overall size of your shed. For roofs that won’t experience heavy snow loads, a gable roof can span up to 22′ with 2×4 rafters.
How far apart should timber battens be?
Each product has different requirements, for example, batten spacing for (0.42BMT) corrugated metal roofing needs to be no more than 1100 mm apart, but batten spacing for 0.48BMT metal roofing can be up to 1600 mm apart.
How do you calculate batten spacing?
Divide the distance between the top and bottom battens by the number of courses. This will give you the batten spacing for your roof, or its batten gauge.
How do you calculate rafter span?
Rafter run = external width between the wall plates divided by two. Rafter span = rafter run divided by cos °.
How far apart should floor joists be NZ?
Floor joists shall comply with NZS 3604. Joists shall be spaced at 600mm centres maximum and shall have a depth of 150mm minimum. Alternative Floor Framing: Use either Hyspan® or Hybeam® HJ series joists designed for strength and serviceability, no less than 150mm deep and spaced at no more than 600mm.
What size timber is used for rafters?
Roof pitch between 30 and 45 degrees with rafter spacing strength class C16
| Size of rafters in mm | 400mm | 600mm |
|---|---|---|
| 100 x 47 | 1.91 | 1.78 |
| 125 x 47 | 2.52 | 2.33 |
| 150 x 47 | 3.14 | 2.88 |
How far apart should roof battens be?
How far can a 2×4 span as a rafter?
Spacing your 2×4 shed rafters at 24” on center limits the width of your roof. For light load roofs, 24” o.c. 2×4 rafters can span up to 7 ⅔’. For heavy loads, 2x4s can span up to 5 ½’.
How far can a roof rafter span over two spans?
●light, couple-close roof ●rafter span 3.000 m continuous over two spans. Step 1 – Rafter spacing The rafter span is 3.000 m, and because this is a light roof, the far right column of NZS 3604:2011 Table 10.1 Rafters for all wind zones(see Figure 2) can be used for rafter spacings at 1200 mm (see Note 4 in Table 10.1).
How do I select the most economic rafter spacing?
This rafter extends over two spans, so the 10% increase can also be used to select the most economic rafter. Look at the values in the span column for 1200 mm rafter spacing.
How do I determine the length of a roof rafter?
Rafter span tables – Use these tables to determine lengths, sizes and spacing of rafters based on a variety of factors such as, species, load, grade, and spacing. Visit the roof framing page for more information on cutting roof rafters, and visit the roof pitch calculator for determining rafter lengths based on rise and run.