About CorroMax 21®
A reliable product that stands the test of time, Fielders® CorroMax 21® can be used in either roofing or walling applications. This profile is both popular and versatile, while being able to reflect either a modern or traditional design depending on the application. Complemented by Fielders® range of heritage products, beautiful authentic restorations can also be achieved. Available in 0.40mm and 0.48 base metal thicknesses.
Material Specifications
| Property | Notes | |||
| Base Metal Thickness (mm) | 0.40 | 0.48 | BMT | |
| Total Coated Thickness (mm) | 0.47* | 0.53* | TCT | |
| Mass / Unit Length | COLORBOND® | 3.40 | 4.00 | kg/m |
| Mass / Unit Area | COLORBOND® | 4.40 | 5.92 | kg/m2 |
| Minimum Yield Strength | G550 | G550 | Base Steel Designation | |
| Coating Class | Z600 (Heritage Galvanised) AM100 (COLORBOND® Steel) AM125 (ZINCALUME® steel) AM150 (COLORBOND® Ultra Steel) Z450 (Galvanised) | Minimum Coating g/m2 of Zinc - Aluminium |
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| Coverage (mm) | 762 | |||
| Tolerance | Length: +10mm, -10mm, Width: +4mm, -4mm | |||
Notes:
- CorroMax 21® is manufactured in accordance to AS 1445 and from materials in accordance to AS 1397 and AS 2728. It is to be installed in accordance with AS 1562 and HB 39.
- The sectional properties are theoretical values per sheet width. These properties are gross values only.
- *is based on Standard COLORBOND®; steel single-sided material. For other painted steel options please contact a Fielders® representative.
Rainfall Capacity
For further information, please refer to sections "Rainfall Intensity" and "Water Carrying Capacity and Rainwater Run-Off".
Maximum Roof Length (m)
| Roof Slope (degrees) | Rainfall Capacity (mm/hr) | ||||||
| 100 | 150 | 200 | 250 | 300 | 350 | 400 | |
| 3 | 41 | 27 | 20 | 16 | 13 | 11 | 10 |
| 4 | 48 | 32 | 24 | 19 | 16 | 13 | 12 |
| 5 | 54 | 36 | 27 | 21 | 18 | 15 | 13 |
Notes:
- Minimum recommended slope is 3°. Sheet lengths greater than 24m are not recommended due to thermal expansion and contraction.
Load Span Tables
Wind Load Capacity: Limit State Design: 0.40mm BMT
| Span (mm) | Single Span | End Span | Internal Span | |||
| Serv. (kPa) | Strength (kPa) | Serv. (kPa) | Strength (kPa) | Serv. (kPa) | Strength (kPa) | |
| 600 | 1.42 | 11.42 | 1.49 | 10.47 | 1.33 | 11.61 |
| 900 | 1.24 | 9.50 | 1.31 | 6.90 | 1.17 | 8.50 |
| 1200 | 0.99 | 7.00 | 1.18 | 5.30 | 1.03 | 6.70 |
| 1500 | 0.88 | 5.20 | 1.10 | 4.32 | 0.90 | 5.50 |
| 1800 | 0.85 | 4.55 | 0.96 | 3.40 | 0.78 | 4.45 |
| 2100 | - | - | 0.81 | 2.65 | 0.70 | 3.55 |
| 2400 | - | - | 0.66 | 2.05 | 0.65 | 2.80 |
Note:
- Values in the table above have been generated based on testing into steel supports with at thickness of 1.0mm.
- Values are based on no insulation under the sheeting.
- Serv. denotes serviceability
Wind Load Capacity: Limit State Design: 0.48mm BMT
| Span (mm) | Single Span | End Span | Internal Span | |||
| Serv. (kPa) | Strength (kPa) | Serv. (kPa) | Strength (kPa) | Serv. (kPa) | Strength (kPa) | |
| 600 | 2.73 | 12.06 | 1.71 | 11.87 | 1.80 | 12.13 |
| 900 | 2.46 | 10.95 | 1.45 | 9.60 | 1.59 | 9.80 |
| 1200 | 1.85 | 8.93 | 1.23 | 8.03 | 1.40 | 8.10 |
| 1500 | 1.30 | 7.40 | 1.03 | 6.65 | 1.25 | 6.38 |
| 1800 | 0.92 | 6.15 | 0.89 | 5.48 | 1.13 | 4.88 |
| 2100 | - | - | 0.80 | 4.32 | 0.80 | 3.85 |
| 2400 | - | - | 0.74 | 3.32 | 0.74 | 3.20 |
| 2700 | - | - | 0.72 | 2.38 | 0.72 | 2.97 |
Note:
- Values in the table above have been generated based on testing into steel supports with at thickness of 1.0mm.
- Values are based on no insulation under the sheeting.
- Serv. denotes serviceability
Figure SR NC 002 End Spans, Internal Spans and Overhangs illustrates the terminology end spans, internal spans, and overhangs and their reference to the supporting substructure. This terminology has been used in the following Maximum Recommended Span and Wind Load Capacity tables.
Figure SR NC 002 End Spans, Internal Spans and Overhangs
Maximum Recommended Roof Cladding Span
| Wind Region | Base Metal Thickness (mm) | Terrain Category 3 | ||
| Single (mm) | End (mm) | Internal (mm) | ||
| B | 0.40 | 750 | 950 | 1350 |
| 0.48 | 950 | 1500 | 1900 | |
Importance Level 2
Maximum Roof Height H = 10m
External Pressure Coefficient:
Cpe = -0.65 for walling
Cpe = -0.9 for roofing
Internal Pressure Coefficient:
Cpi = 0.2
Local Pressure Factor:
KL = 2.0 (end & single span)
KL = 1.0 (internal span)
Table CM21 RS NC 001 - CorroMax 21® Non-Cyclonic
Note:
- For roofs: the data are based on foot-traffic loading.
- Table data are based on supports of minimum 1mm BMT.
Maximum Recommended Wall Cladding Span
| Wind Region | Base Metal Thickness (mm) | Terrain Category 3 | ||
| Single (mm) | End (mm) | Internal (mm) | ||
| B | 0.42 | 1800 | 2400 | 2400 |
| 0.48 | 1800 | 2700 | 2700 | |
Importance Level 2
Maximum Roof Height H = 10m
External Pressure Coefficient:
Cpe = -0.65 for walling
Cpe = -0.9 for roofing
Internal Pressure Coefficient:
Cpi = 0.2
Local Pressure Factor:
KL = 2.0 (end & single span)
KL = 1.0 (internal span)
Table CM21 WS NC 001 - CorroMax 21® Non-Cyclonic
Note:
- For roofs: the data are based on foot-traffic loading.
- For walls: the data are based on pressures (see wind pressure table).
- Table data are based on supports of minimum 1mm BMT.
Pierce Fixing
Fasteners must be selected to match the life expectancy of the cladding material. Recommendations from fastener manufacturers should be sought.
Only fasteners complying with AS 3566:2002 and those that are compatible with the roofing material should be used for its fastening.
Pierce Fixing Table
| Fixing Supports | Crest Fixing | Valley Fixing (Wall only) | Side Lap Fixing |
| Steel 1.0 to 3.0mm | 12-14x35, Metal Teks HG, HH or AutoTeks 12.5-14x39 | 10-16x16, Metal Teks, HH or 10-16x25 Designer Head | (If required) 10-16x16, Metal Teks, HH or Roof Zips M6-11x25 or 10-16x25 Designer Head or Sealed blind rivet ø4.8mm aluminium |
| Timber Hardwood | 12-11x50, Type 17 HG, HH | 10-12x25, Type 17, HH 10-16x25 Designer Head or 12-11x25, Type 17, HH |
|
| Timber Softwood | 12-11x50, Type 17 HG, HH or Roof Zips M6-11x50 HG, HH | 10-12x30, Type 17, HH 12-11x25, Type 17, HH 10-16x25 Designer Head or Roof Zips M6-11x25 |
|
| Metal Battens (0.55 to 1.0mm) | Roof Zips M6-11x50 | 10-16x16, Metal Teks, HH or 10-16x25 Designer Head or Roof Zips M6-11x25 |
Fastener Spacings - Non-Cyclonic
Crest Fastener Location
3 Fasteners per sheet – Internal supports.
Roofing should be lapped away from the prevailing weather.
Valley Fastener Location (Wall Only)
3 Fasteners per sheet – Internal supports.
Figure CM21 FS NC 001
Notes:
1. All fasteners used externally should be fitted with an EPDM seal (washer).
2. Do not use punches to form fastener holes.
Side Lap Fastening
It may be necessary to use side lap fasteners at mid spans when using CorroMax® at maximum spans. These will help to hold the sheet laps firmly in place and maintain a weather-proof joint.
Insulation
Care needs to be taken when installing insulation with roof sheeting. When insulation thickness up to 50mm are installed the screws detailed in Table SR PF NC 001 may need to be increased depending on the thickness and density of the insulation. When the screw is properly tightened into metal there should be a minimum of three (3) threads protruding past the support being fixed in to. For timber the screw must penetrate the timber as much as the screws detailed in Table SR PF NC 001 do without insulation.
For insulation thicknesses greater than 50mm Fielders® recommend the use of a thermal spacer to help maintain Rw values as well as minimising any bulging in the profile caused by the insulation.
CorroMax 21® Installation Procedure
For installation procedures see section “Typical Pierce Fix Installation Guide”. For general handling instructions refer to section “Maintenance and Care”.
Figure CM21 NC Corrugation Laps 003
Maximum Sheet Length
See section “Thermal Expansion and Contraction of Steel Sheeting”.
Turning of Roof Sheeting Ends
Refer to section “Flashings, Cappings & Ends of sheets”.
Figure CM21 NC Pittsburgh Lock-Seam and Snap-Lock 007
Hip Bracing
Figure CM21 NC Type A Hip Bracing 008
Figure CM21 NC Type B Hip Bracing 009
Cappings
Refer to section “Cappings”.