This guide walks you through the full installation process for fibre cement board ceilings and soffits: from taking delivery on site through to the final painted surface. It applies to both the JUMBO imported range and the locally manufactured Gyproc RhinoROC™ boards stocked by Pelican Systems – and references the compatible accessories we carry to complete the job cleanly.
Fibre cement board has become one of the most widely specified materials in South African residential and light commercial construction – and for good reason. It is moisture-resistant, fire-rated, dimensionally stable, and built to last in the harsh conditions our climate throws at it. But as with any building material, the quality of the finished result depends just as much on correct installation as it does on the product itself.
1. Taking Delivery and Storing Boards on Site
Fibre cement board is a dense, heavy material – a 6mm board weighs approximately 8.6 kg/m², and a 9mm board even more. Improper handling on delivery is one of the most common causes of edge chipping and surface scuffing before installation even begins.
Off-loading
- Handle boards carefully to avoid strain or damage.
- Lift each board upright – do not slide boards off the delivery stack, as this causes scuffing to face surfaces and edges.
- Always use two people when moving boards.
Carrying and Stacking
- Always carry boards on their edge (long edge vertical), never flat.
- When lifting, keep the long edge in contact with the stack below.
- Never lift boards with the face parallel to the ground – this places excessive bending stress on the board and can cause breakage, particularly on longer lengths.
Storage
- Store boards flat on a level surface, well supported and off the ground.
- Keep boards dry and protected from rain before installation.
- Do not stand boards upright unsupported against a wall – they can topple.
2. Cutting Fibre Cement Board
The right cutting method depends on the board thickness. Thinner boards score and snap cleanly with a utility knife; heavier boards benefit from power tools for a neater, more controlled result. In all cases, cut outdoors or in a well-ventilated area – fibre cement cutting generates fine silica dust – and always wear a P2-rated dust mask, safety glasses, and hearing protection.
4mm Board – Score & Snap (Easiest Method)
- Use a utility knife or tungsten carbide scoring knife and a straight edge.
- Score firmly along the cut line – 3 to 4 firm passes are recommended.
- Snap the board over the straight edge – it will break cleanly along the scored line.
- Clean up the snapped edge lightly with a file or abrasive paper if needed.
6mm Board – Score & Snap or Circular Saw
Option 1: Score & Snap (still works well)
- Same method as 4mm, but score deeper with more passes to ensure a clean break.
Option 2: Circular Saw (for cleaner or more complex cuts)
- Use a circular saw fitted with a carbide-tipped, diamond, or cement-specific blade.
- Preferred for curves, apertures, or any cut requiring greater precision.
9mm Board – Power Tools Recommended
- Use a circular saw or angle grinder for straight cuts.
- Blade selection: use a carbide-tipped, diamond, or cement-specific blade for best results.
- Power tools must only be operated by trained and competent individuals.
Pre-cutting Apertures
Cut all openings for downlights, exhaust fans, and other penetrations before fixing boards to the ceiling frame. It is significantly easier to cut apertures on a workbench than overhead in position.
3. Preparing the Frame – Timber Brandering
Both JUMBO and RhinoROC™ boards are fixed to timber Brandering. The quality of the frame directly affects the flatness and longevity of the finished ceiling, so it is worth getting this right before a single board goes up.
- Ensure Brandering is straight, level, and securely fixed to the structure above.
- Brandering centres should be set to suit the board thickness and span requirements – refer to the Saint-Gobain installation details for RhinoROC™, or the JUMBO technical data sheet, for recommended spacing.
- All board ends and edges must be supported by Brandering – unsupported edges will flex and crack over time.
- Check that the frame is free of twist and that all members are in the same plane before boarding commences.
4. Fixing Boards to the Ceiling
Board orientation and fixing method both matter for a neat, durable result.
Board Orientation
- Install fibre cement boards with the smoother side facing down (the finished face that will be visible and painted).
- Stagger board joints between rows – running joints through on the same Brandering member creates a visible crack line over time.
Fixing
- For JUMBO boards, fix with appropriate corrosion-resistant screws or nails suited to the board thickness and the Brandering material.
- For RhinoROC™ 4mm and 6mm boards, fix to timber Brandering at the required spacing centres with appropriate fixings.
- Fixings should be set back a minimum of 10–15mm from board edges to avoid splitting.
- Do not over-drive fixings – the head should sit flush with the surface, not countersunk below it.
- Follow the manufacturer’s recommendations for fixing spacing along the board length and across the width.
5. Jointing – M-Strip and H-Strip Profiles
The joint between boards is one of the most visible – and most vulnerable – elements of a fibre cement ceiling. Pelican Systems stocks proprietary jointing profiles that make this straightforward.
H-Strip
- Used at internal butt joints between two boards running side-by-side.
- Slide the H-Strip over the edges of adjacent boards before fixing the second board in place, or clip into position after boarding.
- Ensures a clean, consistent reveal at every joint without the need for tape and filler.
Aluzinc M-Strip
- Used at perimeter edges and where the ceiling meets a wall or structural element.
- Fix the M-Strip to the Brandering or wall before boarding, then slide the board edge into the profile.
- Provides a clean, finished edge that accommodates minor movement without cracking.
General Jointing Advice
- Always use jointing profiles in accordance with the manufacturer’s instructions.
- Do not attempt to fill or tape fibre cement butt joints without the correct backing profile – crack-free results are difficult to achieve without it.
6. Soffit and Eave Installations – What Changes Outdoors
Fibre cement board’s moisture and weather resistance makes it an excellent choice for exposed soffits and eaves. However, outdoor applications do require some additional considerations.
- Use the correct board grade: the JUMBO 6mm and 9mm boards are suited to eave and soffit applications. For RhinoROC™, the 6mm board is rated for outdoor use; the 4mm board is for interior applications only.
- Ensure all cut edges are sealed with a suitable primer before installation – cut edges are more permeable than the face.
- Fixings for outdoor soffits must be corrosion-resistant (hot-dip galvanised or stainless steel) to prevent rust staining on the face.
- Maintain a gap between the bottom of the board and any surface where water could pond – even moisture-resistant board should not sit in standing water.
- For fascia installations, Pelican Systems stocks the JUMBO Fascia Board (225 x 3000mm imported) and a locally produced Fascia Board in both 3000mm and 3600mm lengths. PVC joiners are available to connect lengths neatly.
7. Priming and Painting the Finished Surface
Fibre cement board is not a ready-to-paint surface straight off the pallet. Correct priming is essential for paint adhesion and long-term appearance.
Priming
- After jointing is complete, apply a suitable alkali-resistant primer to all board faces and any exposed cut edges.
- Allow the primer to cure fully before proceeding to topcoats – follow the primer manufacturer’s drying times.
- New fibre cement board has a high alkalinity that can cause adhesion failure or colour shift with some paints if not correctly primed first.
Topcoat
- RhinoROC™ and JUMBO boards can be painted or finished in accordance with the paint manufacturer’s specifications.
- For outdoor soffits and eaves, always use high-quality exterior-grade coatings specifically formulated for fibre cement.
- Interior ceilings may be finished with standard ceiling paint over a correct primer.
- Smooth board surfaces take paint evenly – avoid thick, uneven coats which can highlight surface irregularities.
8. The Pelican Systems Fibre Cement Range at a Glance
Pelican Systems stocks a complete range of fibre cement boards and accessories for ceiling and soffit applications:
Get in Touch
For technical data sheets, pricing, or to discuss your project requirements, contact the Pelican Systems team in Durban:
Tel: (031) 563 7307 | Email: info@pelican.co.za | Web: www.pelican.co.za
Our team can advise on product selection, quantities, and which accessories are needed for your specific ceiling or soffit application.
© Pelican Systems 2026. This guide is intended as general installation advice. Always refer to the relevant manufacturer’s technical data sheet and comply with applicable SANS standards for your specific project.