A rooftop walkway does more than give people somewhere to put their feet. It defines a safe route, spreads load away from vulnerable sheeting and provides grip on surfaces that become slippery in rain, dust or algae. The choice between aluminium and FRP shapes how well that route performs over the life of the roof.
Written by: Yatin Chaudhary, TsaF.
Why fit a walkway at all?
On metal-sheeted industrial roofs, people tend to walk wherever looks easiest. Over time that wears paths through coatings, dents sheet crowns, loosens fasteners and causes leaks. On fibre cement or older sheets, it can put people on surfaces that may not carry them. A walkway addresses these problems by:
- marking one visible route from the access point to plant and work areas;
- spreading foot traffic so the roof sheet is not loaded at weak points;
- giving a slip-resistant surface on sloping or wet roofs;
- keeping people away from skylights, edges and other hazards along the way;
- reducing the damage and leak repairs caused by uncontrolled foot traffic.
A walkway is a route, not edge protection. Where the route runs close to an unprotected edge or opening, it needs handrails, a barricade or another measure alongside it.
Aluminium walkways
Aluminium walkways are made from extruded alloy sections assembled into modules that sit on the roof profile. Surfaces vary to suit the use: chequered, perforated, grille, ladder-rung, serrated and T-profile designs are all common. A typical TsaF module is 2,000 mm long with a 600 mm clear walking width, which suits single-file maintenance traffic.
Strengths
- Light and stiff: easy to handle on the roof, and rigid enough to bridge between supports on most sheet profiles.
- Corrosion resistance: aluminium forms a natural oxide layer that performs well in most industrial and urban atmospheres.
- Durability: does not degrade in sunlight, and the metal is fully recyclable at end of life.
- Versatile fixing: can often be fixed without penetrating compatible roof profiles.
Watch-outs
- Galvanic corrosion: contact with dissimilar metals, such as some steel fixings or copper, needs isolation.
- Aggressive atmospheres: strongly alkaline or certain chemical environments can attack aluminium.
- Conductivity: aluminium conducts electricity, which matters near live electrical equipment.
FRP walkways
FRP (fibre-reinforced plastic, also called GRP) gratings are made from glass fibres set in a resin, either moulded into a grid or pultruded into bars. They are widely used in chemical, water treatment and electrical environments.
Strengths
- Chemical and corrosion resistance: with the right resin, FRP resists many acids, alkalis and salts that would attack metals.
- Non-conductive and non-magnetic: useful around electrical plant and sensitive equipment.
- Low thermal conductivity: the surface stays cooler to touch than metal in direct sun.
- Light weight: comparable handling to aluminium on the roof.
Watch-outs
- UV exposure: long-term sunlight can degrade unprotected resin and expose surface fibres. Ask whether the product is UV-stabilised.
- Fire behaviour: depends on the resin system. Ask for the relevant specification if fire performance matters on your roof.
- Stiffness and impact: FRP is generally more flexible than an aluminium section of similar depth, so support spacing must suit it, and heavy impacts can crack it.
Aluminium vs FRP at a glance
| Factor | Aluminium | FRP |
|---|---|---|
| Weight | Light | Light |
| General corrosion resistance | Good in most atmospheres | Very good; depends on resin |
| Chemical environments | Check against the specific chemicals | Often preferred; check resin compatibility |
| Electrical conductivity | Conductive | Non-conductive |
| Sunlight (UV) | Unaffected | Needs UV-stabilised resin; monitor surface |
| Stiffness for a given depth | Higher | Lower; may need closer supports |
| Impact damage | Tends to dent | Can crack |
| Surface heat in sun | Warmer to touch | Cooler to touch |
| End of life | Recyclable metal | Harder to recycle |
Matching the material to the site
Warehouses, PEB buildings and general manufacturing
Aluminium is usually the default choice. It is durable, light, unaffected by sunlight and suits trapezoidal and standing seam roofs, which are the most common profiles on these buildings.
Coastal and heavy industrial atmospheres
Both materials can work. The decision often depends on the specific pollutants and on the fixings: stainless steel fasteners with appropriate isolation help aluminium, while FRP avoids metal corrosion altogether in the walking surface.
Chemical, pharmaceutical and FMCG plants
Where roofs receive exhaust from process vents or regular chemical splash, FRP is often worth considering. Share the list of chemicals present with your supplier so the resin can be checked.
Power, transmission and electrical plant
Near live equipment, FRP’s non-conductive nature can be an advantage. It does not replace electrical safe-working procedures, but it removes one conductive path.
Surface profile and slip resistance
The surface matters as much as the material. Perforated and grille profiles let water and debris drain through, which helps on roofs that see heavy rain or dust. Chequered and serrated surfaces give positive grip, and ladder-rung profiles help on steeper pitches. TsaF walkways are designed with reference to EN 516 and DIN 4426 and an R11 slip rating; refer to the product datasheet for the variant you are considering.
Whichever surface you choose, keep it clean. Moss, algae, oil and dust build-up can reduce grip on any material.
Fixing to the roof
How the walkway is fixed affects both its stability and the roof’s weatherproofing. On standing seam roofs, non-penetrating clamps grip the seams. On trapezoidal sheet, fixings are made into the crowns with sealed rivets or screws. On very low pitches, walkways can also be laid across the fall using an adhesive pad and rivet arrangement. Walkway modules can often be retrofitted over existing steel or GRP walkways that have deteriorated.
A good layout also includes crossover steps where the route meets pipes, ducts or ridge lines, and handrails wherever the walkway runs near an edge. The Aluminium & FRP Walkway System page sets out the profiles, fixing options and accessories available.
Planning the route
Material choice matters less than a route that people will actually follow. If the walkway takes a long detour, workers will cut across the roof sheet instead. When planning the layout:
- Start at the access point. The walkway should begin where people arrive on the roof, whether a ladder, hatch or stair door, so there is no unprotected step onto bare sheeting.
- Connect every regular destination. Plant, drains, gutters, vents and solar arrays that are visited routinely should each be reached from the main route.
- Keep a safe distance from hazards. Route the walkway away from edges and roof lights where possible, and add handrails or skylight mesh where it cannot be moved.
- Allow for the work, not just the walk. Provide wider platforms where technicians kneel, set down tools or open plant panels.
- Leave room to grow. If more plant or solar panels are planned, design the route so it can be extended without rework.
Thinking about whole-life cost
The cheapest walkway on the day of purchase is not always the cheapest over the life of the roof. Compare the cost of the material and fixings with the likely cost of replacing sections, repairing roof damage and managing leaks if a walkway performs poorly in your environment. On an ordinary warehouse, a well-fixed aluminium walkway is usually a low-maintenance choice. On a roof that receives chemical exhaust, the extra cost of a suitable FRP grating may pay for itself by avoiding corrosion-related replacement. Ask suppliers to explain the expected maintenance for their recommendation, not only the supply price.
Questions to ask before you specify
- Which roof profile and pitch is the walkway being fixed to, and is fixing penetration-free?
- What chemicals, salts or exhaust gases does the roof see?
- Is the route near live electrical equipment?
- Which surface profile suits the expected rain, dust and pitch?
- Does the route pass edges, skylights or obstructions that need handrails, mesh or crossover steps?
- What inspection is recommended, and what does the supplier check during maintenance?
Keeping walkways in service
Walkways sit exposed to weather all year. Periodic inspection should look for damaged, corroded, loose or displaced sections, check joints, supports and fixings, confirm alignment and stability, and assess the slip-resistant surface. For FRP, inspectors also look for signs of surface deterioration such as exposed fibres or cracking.
Next step
The right walkway depends on your roof profile, your environment and how people use the roof. TsaF engineers can walk your roof, plan the route and recommend the material and surface that suit your site. Request a site assessment to discuss your requirements.
