IBR & Corrugated Roofing Guide South Africa
Compare sheet descriptions, distinguish effective cover from overall width, and prepare an accurate roofing enquiry.
Understand IBR roof sheeting labels, WFSA sheet lengths, effective cover, thickness, coatings and material estimating.
View specification tablesShop related products ↗What does IBR mean?
IBR means Inverted Box Rib. Its angular profile differs from the rounded wave shape of corrugated sheeting. Profile shape is only one element of selection: steel thickness, material properties, coating, supports and fixing requirements also matter.
IBR and corrugated are different profiles. Compare the effective cover and matching accessories for the actual sheet supplied; do not interchange their widths or installation details.
WFSA listed IBR sheets
| Length | Listed range / thickness label | Product |
|---|---|---|
| 3.6m | <0,30mm / ECO | View sheet ↗ |
| 3.6m | <0,40mm / ECO | View sheet ↗ |
| 3.6m | <0,50mm / ZA | View sheet ↗ |
| 4.2m | <0,30mm / ECO | View sheet ↗ |
| 4.2m | <0,50mm / ZA | View sheet ↗ |
| 6.0m | <0,50mm / ZA | View sheet ↗ |
| 6m | <0,30mm / ECO | View sheet ↗ |
| 6m | <0,40mm / ECO | View sheet ↗ |
These titles preserve the “less than” thickness notation used by the store. Do not present <0.30 mm, <0.40 mm or <0.50 mm as a guaranteed exact thickness. ZA and ECO are listed range labels; the titles alone do not establish a coating composition or coating mass.
How to read an IBR description
IBR / 3.6m / <0,40mm / ECO states the profile, listed sheet length, thickness label and range. It does not state effective cover, support spacing, minimum pitch or wind resistance.
Ask whether a quoted thickness is base metal thickness or includes the coating and how it is measured. Keep nominal thickness, actual measured thickness and permitted tolerances distinct. A lighter sheet should not replace a specified thicker or higher-grade sheet without approval.
Overall width versus effective cover
Overall width is the sheet’s total physical width. Effective cover is the width added to the completed roof after the required side lap. Estimate roof coverage with the effective cover for the exact profile.
What is the effective cover of IBR 686?
WFSA’s primary IBR 686 profile provides an effective cover width of 686 mm per correctly installed sheet with the specified side overlap.
What is the effective cover of 8.5 corrugated?
WFSA’s primary 8.5 corrugated profile provides an effective cover width of 610 mm per correctly installed sheet. Do not use a 762 mm cover calculation for this profile.
Roof pitch, support spacing, fixing and lap details for a different corrugated profile must not be transferred to 8.5 corrugated.
How many sheets do I need?
Sheets across one roof plane = ceiling(required covered width ÷ confirmed effective cover). Determine the required length from the roof slope, overhangs, flashings and any designed end laps. Roof plan area alone is not a cutting schedule.
Worked example only: a 10 m wide roof plane with a confirmed 0.686 m effective cover needs ceiling(10 ÷ 0.686) = 15 sheets across. If that plane requires full 4.2 m sheets without end laps, the gross effective coverage represented by those strips is 15 × 0.686 × 4.2 = 43.218 m². Edge trimming and roof geometry still need checking.
The example uses the confirmed IBR 686 effective cover; required sheet length and whether 4.2 m is suitable still depend on your roof layout. Complex roofs require a layout separating every plane, hips, valleys, ridges and penetrations.
Roof Sheet Quantity Calculator
Estimate the number of sheets across one roof plane. IBR 686 uses 0.686 m effective cover; 8.5 corrugated uses 0.610 m. The result rounds up. Determine slope length, end laps, trimming and roof accessories separately.
Sheet length and roof slope
Measure along the roof slope, not only along its horizontal plan. Include the details required at the eaves and upper end. If a single sheet cannot span the required length, end laps change the useful coverage and fixing requirements.
Use a drawing or measured roof layout before choosing among the listed 3.6, 4.2 and 6 m lengths. Long sheets require suitable support during transport, unloading and lifting to prevent distortion. Confirm site access and safe handling with the delivery arrangement.
Thickness and span are separate checks
Do not assign a safe purlin spacing from the shop’s thickness label alone. The exact profile, steel properties, thickness, loads, support arrangement, fasteners and local exposure determine the required design.
This guide does not publish a universal maximum span, minimum pitch or wind rating for unverified WFSA sheet variants.
Coatings and compatibility
For the complete explanation of zinc, alloy and outer coating systems, read the WFSA Corrosion, Galvanizing & Protective Coatings Guide.
Consider marine, industrial and agricultural exposure and any applicable manufacturer warranty conditions.
Do not assume ZA proves a particular Aluzinc composition or that ECO establishes a standardized coating class. Check compatibility with fasteners, flashing, contact materials and runoff from other metals. Do not transfer a competing supplier’s certification or warranty to a WFSA item.
Side laps, end laps and flashings
Side laps affect effective cover; end laps affect the useful length where sheets are joined along the slope. Use the supplied profile’s approved installation detail for lap direction, sealing and fixing.
Ridges, valleys, eaves, penetrations and wall junctions need the correct flashing details. A roof that has enough sheet area can still leak if these interfaces are poorly planned. Do not use a universal lap dimension or minimum slope without the exact product’s requirements.
Roof screws and fastening details
| Product | Link |
|---|---|
| Roof Screws / w / 65mm CQ / BOX | View fastener ↗ |
| Roof Screws / w / 65mm / CQ / 100 Pack | View fastener ↗ |
| Roof Screws / w / 75mm / CQ / 100 Pack | View fastener ↗ |
| Roof Screws / w / 90mm / CQ / 100 Pack | View fastener ↗ |
Length alone does not determine a suitable fastener. Check substrate, required engagement, diameter, thread, corrosion protection, sealing components and the specified fixing position and pattern. The “w” in the title should not be used as proof of a particular washer type.
Over-tightening or under-tightening can damage the assembly; follow the approved fastener and sheet installation requirements.
Handling, storage and installation safety
Long roof sheets have sharp edges and can catch the wind. Use appropriate gloves, controlled lifting and a safe work plan. Roofing work needs suitable access, fall protection and trained people; do not step onto unsupported or unverified sheeting.
Store according to the supplied product’s requirements, with appropriate support and protection from trapped moisture. Inspect bundles for handling damage. Use compatible cutting equipment, remove cutting debris safely and manage swarf so it does not remain on the finished roof.
Inspection and maintenance
Check fasteners, flashings, joints, drainage paths, debris and any damaged coating as part of the roof’s maintenance plan. Avoid cleaning methods or chemicals incompatible with the finish.
A leak near a sheet lap may have originated at an upstream flashing or penetration. Inspect the complete roof detail rather than repeatedly adding sealant to a visible wet spot. Use qualified assistance where access or repair would create a fall risk.
Roofing quotation checklist
- Roof plan and slope measurements for each plane.
- Required profile and confirmed effective cover.
- Actual thickness basis, range, steel grade and coating.
- Required lengths and quantities, including the cutting layout.
- Support and fixing specification.
- Ridges, valleys, wall flashings and penetrations.
- Site exposure, delivery address and unloading access.
Use a roofing professional for the roof design and installation requirements.
Shop IBR roofing at WFSA
Browse the IBR Roofing category for the listed sheets and screws. Contact a branch to confirm the actual profile, technical data, accessory requirements and availability.
Online prices apply to Centurion only. Bloemfontein and George can confirm their own branch prices and supply arrangements. For steel supports and related material, browse the Steel category against your approved roof specification.
Frequently asked questions
What does IBR stand for?
Inverted Box Rib, an angular profiled sheet.
Is IBR the same as corrugated roofing?
No. Their profile shapes differ; check the exact sheet specifications and accessories.
What lengths does WFSA list?
The reviewed range includes 3.6 m, 4.2 m and 6 m sheets. Not every thickness label appears in every length.
Does <0.40 mm mean exactly 0.40 mm?
No.
What is effective cover?
The width of roof covered by a sheet after the specified side lap.
Does all IBR cover 686 mm?
WFSA’s primary IBR 686 profile has a 686 mm effective cover. Confirm the ordered profile before calculating; other profiles may differ.
How do I calculate sheets across a roof?
Divide the required covered width by confirmed effective cover and round up; check the full layout and sheet lengths separately.
Can I calculate sheet quantity from plan area alone?
Not reliably. Slope length, laps, roof geometry, trimming and accessories matter.
What purlin spacing should I use?
Use the approved design and load/span data for the exact sheet. No universal spacing is given here.
What roof pitch is allowed?
Does ZA
The shop label alone does not establish coating composition or mass. Ask WFSA for the specification.
Which screw length should I buy?
Match the substrate, engagement, sealing and fixing specification. Length alone is insufficient.
Need product assistance?
Send the full specification, quantities and delivery location to your nearest WFSA branch.
Request a quote ↗Explore all guides ↗WFSA IBR, Corrugated & Roofing Supply Range
WFSA supply range: Available from WFSA — request a quotation. Contact WFSA for current branch availability, lead time and the exact combination required. A listed range does not mean every branch holds every item at all times.
Current online products: Shop links identify published online listings. The online shop shows only part of the WFSA supply and manufacturing range; additional range items can be ordered by quotation.
| Profile | Effective cover |
|---|---|
| IBR 686 | 686 mm |
| Corrugated 8.5 | 610 mm |
| Corrugated 10.5 | 762 mm |
Use effective cover, not overall sheet width, for quantity estimates. Fixed-length COR products must be quoted with their actual rib profile. A per-metre supply basis does not mean a 1 m sheet is the only available length.
| Profile | Supply length / basis | Range / finish label | Listed thicknesses |
|---|---|---|---|
| Corrugated | 6m | ECO | <0.18mm, <0.22mm, <0.25mm, <0.27mm, <0.30mm, <0.32mm, <0.37mm, <0.40mm, <0.42mm, <0.47mm, <0.50mm |
| Corrugated | 6m | Z275 | <0.50mm |
| Corrugated | 6m | POLY | <0.80mm, <1.00mm |
| IBR 686 | 6m | ECO | <0.22mm, <0.25mm, <0.27mm, <0.30mm, <0.32mm, <0.37mm, <0.40mm, <0.42mm, <0.47mm, <0.50mm |
| IBR 686 | 5.4m | ECO | <0.30mm |
| IBR 686 | 6.6m | ECO | <0.30mm |
| IBR 686 | 6m | ZA | <0.40mm, <0.47mm |
| IBR 686 | 6.0m | ZA | <0.50mm |
| IBR 686 | 6m | Z275 | <0.50mm |
| IBR 686 | 6m | POLY | <0.80mm, <1.00mm, <1.20mm |
| Corrugated | 4.2m | ECO | <0.18mm, <0.22mm, <0.25mm, <0.27mm, <0.30mm, <0.32mm, <0.37mm, <0.40mm, <0.42mm, <0.47mm, <0.50mm |
| Corrugated | 4.2m | Z275 | <0.50mm |
| IBR 686 | 4.2m | ECO | <0.22mm, <0.25mm, <0.27mm, <0.30mm, <0.32mm, <0.37mm, <0.40mm, <0.42mm, <0.47mm, <0.50mm |
| IBR 686 | 4.8m | ECO | <0.30mm |
| IBR 686 | 4.2m | ZA | <0.40mm, <0.47mm, <0.50mm |
| IBR 686 | 4.2m | Z275 | <0.50mm |
| Corrugated | 3.6m | ECO | <0.18mm, <0.22mm, <0.25mm, <0.27mm, <0.30mm, <0.32mm, <0.37mm, <0.40mm, <0.42mm, <0.47mm, <0.50mm |
| Corrugated | 3.6m | ZA | <0.30mm |
| Corrugated | 3.6m | Z275 | <0.50mm |
| IBR 686 | 3.6m | ECO | <0.22mm, <0.25mm, <0.27mm, <0.30mm, <0.32mm, <0.35mm, <0.37mm, <0.40mm, <0.42mm, <0.47mm, <0.50mm |
| IBR 686 | 3.0m | ECO | <0.30mm |
| IBR 686 | 3.0m | ZA | <0.40mm |
| IBR 686 | 3.6m | ZA | <0.40mm, <0.47mm, <0.50mm |
| IBR 686 | 3.6m | Z275 | <0.50mm |
| Corrugated 8.5 | Per metre / made-to-length quotation | ECO | <0.18mm, <0.22mm, <0.25mm, <0.27mm, <0.30mm, <0.32mm, <0.37mm |
| Corrugated 10.5 | Per metre / made-to-length quotation | ECO | <0.40mm, <0.42mm, <0.47mm, <0.50mm |
| Corrugated 10.5 | Per metre / made-to-length quotation | POLY | <0.80mm, <1.00mm |
| Corrugated 8.5 | Per metre / made-to-length quotation | Z100 | <0.25mm, <0.27mm, <0.30mm |
| Corrugated 10.5 | Per metre / made-to-length quotation | Z100 | <0.40mm |
| Corrugated 10.5 | Per metre / made-to-length quotation | Z150 | <0.47mm |
| Corrugated 10.5 | Per metre / made-to-length quotation | Z275 | <0.50mm, <0.58mm, <0.80mm |
| IBR 686 | Per metre / made-to-length quotation | ECO | <0.22mm, <0.25mm, <0.27mm, <0.30mm, <0.32mm, <0.37mm, <0.40mm, <0.42mm, <0.47mm, <0.50mm |
| IBR 686 | Per metre / made-to-length quotation | POLY | <0.80mm, <1.00mm, <1.20mm |
| IBR 686 | Per metre / made-to-length quotation | Z100 | 0.40mm |
| IBR 686 | Per metre / made-to-length quotation | Z150 | 0.47mm |
| IBR 686 | Per metre / made-to-length quotation | Z275 | 0.50mm, 0.58mm, 0.80mm |
| Corrugated 8.5 | Per metre / made-to-length quotation | ALUZINC | <0.22mm, <0.25mm, <0.27mm, <0.30mm |
| IBR 686 | Per metre / made-to-length quotation | ALUZINC | 0.27mm, 0.30mm, 0.35mm, 0.40mm, 0.47mm, 0.50mm |
| IBR 686 | Per metre / made-to-length quotation | AZ150 | 0.47mm |
| IBR 686 | Per metre / made-to-length quotation | SPECTRAMAG150 | 0.47mm, 0.53mm |
| IBR 686 | Per metre / made-to-length quotation | ECO/colour | 0.27mm, 0.30mm, 0.35mm, 0.40mm, 0.47mm, 0.50mm |
| IBR 686 | Per metre / made-to-length quotation | Z200/colour | 0.50mm, 0.58mm, 0.80mm |
| IBR 686 | 3.0m | ECO/CD/Grey | <0.40mm |
| IBR 686 | 3.6m | ECO/CD/Grey | <0.40mm |
| IBR 686 | 4.2m | ECO/CD/Grey | <0.40mm |
| IBR 686 | 6.0m | ECO/CD/Grey | <0.40mm, <0.50mm |
| Corrugated 8.5 | Per metre / made-to-length quotation | ECO/CD | 0.27mm, 0.30mm, 0.35mm, 0.40mm, 0.50mm |
| Corrugated 10.5 | Per metre / made-to-length quotation | Z200/CD | 0.50mm, 0.58mm, 0.80mm |
| Product specification | Listed lengths |
|---|---|
| Roll Top Ridging [length] / 0.30mm / ECO | 3.0m, 3.6m, 6.0m |
| Roll Top Ridging [length] / 0.40mm / ECO | 3.0m, 3.6m, 6.0m |
| Roll Top Ridging 0.30mm Galv | As described |
| Roll Top Ridging 0.35mm Galv | As described |
| Roll Top Ridging 0.40mm Galv | As described |
| IBR Ridging 0.35mm Galv | As described |
| IBR Ridging 0.40mm Galv | As described |
| Roll Top Ridging 0.35mm Colour | As described |
| Roll Top Ridging 0.40mm Colour | As described |
| IBR Ridging 0.35mm Colour | As described |
| IBR Ridging 0.40mm Colour | As described |
| Super Roof Charcoal [length] / 0.30mm | 4.8m, 6.0m |
| Super Roof Charcoal [length] / 0.40mm | 4.8m, 6.0m |
| SR Ridging Charcoal [length] / 0.30mm | 3.0m |
| Super Roof Tile Charcoal [length] / 0.35mm | 1.7m |
| Super Roof Tile Ridging Charcoal [length] / 0.35mm | 1.7m |
Range and coating labels describe the listed product.
Less-than thickness descriptions such as <0.30 mm are retained; they are not changed into exact certified nominal thickness claims. The fastener specification must match the support and roofing system.
Additional Roofing Profile Information
The listed Super Roof sheet has 850 mm overall width and 800 mm effective cover. The listed Super Roof tile is 1.7 m long × 420 mm wide, with a stated 1.69 tiles per square metre. Confirm profile, lap arrangement, coverage and installation details with the ordered product; these products are separate from IBR 686 and corrugated 8.5 / 10.5.