Brownbuilt 900 Limit State Load / Span Capacity Chart
Non-Access Roof or Wall
Restricted - Access Roof
Unrestricted Access
(span in mm, distributed serviceability and ultimate loads in kPa)
|
Duraclad 1.7mm |
End Span Internal Span Serviceability Ultimate |
N/R |
800 900 N/A 4.5
|
1000 1200 N/A 4.5
|
1100 1300 N/A 4.5 |
1400 1700 N/A 3.2 |
1700 2100 N/A 1.7 |
Duraclad 1.7mm | |
| End Span Internal Span Serviceability Ultimate | N/R |
| End Span Internal Span Serviceability Ultimate | 800 900 N/A 4.5 |
| |
| End Span Internal Span Serviceability Ultimate | 1000 1200 N/A 4.5 |
| |
| End Span Internal Span Serviceability Ultimate | 1100 1300 N/A 4.5 |
| End Span Internal Span Serviceability Ultimate | 1400 1700 N/A 3.2 |
| End Span Internal Span Serviceability Ultimate | 1700 2100 N/A 1.7 |
Notes
- In any category, spans above the maximum shown should not be used. Category 1 and 2 maximum spans are based on static point load testing as a guide, and further limited by practical experience of roof performance under dynamic foot traffic loads. Category 3 maximum spans are limited as a guide top achieving satisfactory appearance for wall cladding.
- Loads given are based on 6 screw fasteners/sheet/purlin.
- Loads given are limited to a maximum of kPa. If design requirements exceed this limit, contact Dimond for specific advice
- N/R = not recommended.
- For the purposes of serviceability design, the serviceability limit, limited by permanent rib deformation, occurs essentially at the same load as ultimate failure which is the point of disengagement of the roof with the clip
- End span capacities given in this table are based on the end span being 2/3 of the internal span.
- Design Criteria for Limit State Capacities
Serviceability Limit State
No deflection or permanent distortion that would cause unacceptable appearance, side lap leakage or water ponding, due to foot traffic point loads, inward or outward wind loads or snow loads.
Ultimate Limit State
No sheet detachment from clips or fastener withdrawal resulting in clip detachment due to wind up-lift (outward) loads.
System Design
The span capacity of Brownbuilt 900 is determined from the Brownbuilt 900 Limit State Load / Span Capacity Chart using the sections of the Chart appropriate to the grade and type of material, and to the category of serviceability selected from the three categories below. It is recommended that to obtain a dependable design strength capacity for the ultimate limit state, a reduction factor of ɸ = 0.8 is applied. The capacities given do not apply for cyclonic wind conditions.
Serviceability Requirements
While these categories are given for design guidance to meet the serviceability limit state criteria, foot traffic point load damage may still occur if there is careless placement of these point loads.
Non-Access Roof or Wall - Walls or roofs where no foot traffic access is possible or permitted. If necessary, "No Roof Access" signs used.
Restricted - Access Roof - Expect occasional foot traffic educated to walk only on the purlin lines, in the profile pans, or carefully across two profile ribs. Walkways installed where regular traffic is expected, and "Restricted Access" signs placed at access points.
Unrestricted Access - Expect regular foot traffic to access the roof for maintenance work and able to walk anywhere on the roof. No congregation of foot traffic expected.