Not all floor gratings that claim to have a flat top surface actually do, but unfortunately this is something that is commonly misunderstood in the industry and often leads to specifiers and buyers using a product that will not meet the requisite parameters on a project. Grating made from flatbar (not slit strip) has a rounded or mill-edge which explains the differentiation between “true” flat top and “pretend” flat top.

Lance Quinlan, national technical sales consultant at Andrew Mentis, says the company is the only producer of floor grating that is able to supply a product that has a true flat top surface.

“This is a significant differentiator in the floor grating market and is something that should be factored in when making the decision to specify or purchase flat top floor grating. If it isn’t then specifiers and buyers are comparing apples with pears,” Quinlan says.

He explains that Andrew Mentis, with its over 60 years of experience in the manufacture of floor grating products, has continued to invest in the correct equipment and infrastructure to be able to produce the most appropriate finish on its range of floor gratings. Having the best-in-class manufacturing facility coupled with an in-depth knowledge of floor grating applications has enabled the company to stay abreast of international trends and offer the African market world class floor grating products.

“We are the only facility that purchases coiled steel and makes use of our own slitting process which is engineered to produce a truly flat top surface,” Quinlan says. “What is important is that our Mentis Flat Top floor grating has a non-slip surface as a result of this manufacturing process and this significantly enhances the safety of our product.”

This highly engineered floor grating product is produced at Andrew Mentis’ ISO-accredited facility at Elandsfontein, Johannesburg, and is manufactured using a pressure locking system pioneered by the company.

The locking characteristics guarantee the structural integrity of the product and further enhance its integrity. The transversals on the floor grating are positively and permanently locked to the bearer bars and the locking method at the intersections is designed to use the full depth of the bearer bar when calculating loads. This attention to detail ensures that the load bearing capacity is top of mind when design and manufacturing is undertaken.

Mentis Flat Top floor grating is available ex-stock in open ended systems 2 400 mm by 1 200 mm with bearer bar sizes of 25 mm by 4.5 mm, 30 mm by 4.5 mm and 40 mm by 4.5mm. Various apertures are available including Mentis RS40 (40/40mm), RS40 (45/40mm) and RS40 (45/50mm) in unpainted mild steel, bitumen painted mild steel and galvanised. Andrew Mentis also carries certain quantities of RS40 (40/40mm) in stainless steel, 3CR12 and 304.


On-site safety remains a major focus for all industries. While slips, trips and falls can be attributed to a number of factors, inadequately designed and manufactured walkways remain a primary contributor to on-site accidents.

According to Lance Quinlan, national technical sales consultant at Andrew Mentis, organisations need to make it their business to determine whether the walkway products they are using are manufactured from high quality, application-specific material. “The same level of emphasis on safety also applies to the use of expanded metal for guardrails and protection cages, filter and machine motor covers, lift side walls and ladder rungs.

“There are questions one should ask of an expanded metal supplier before committing to the installation of these products. Firstly, does the product comply with the requisite SABS standards? Secondly, does the supplier manufacture products in accordance with ISO quality standards? Another telling factor is if, on visual inspection, there are cracks between the knuckles or if the strands appear too thin,” says Quinlan.

He explains that Andrew Mentis regularly submits expanded metal samples to the SABS and its manufacturing facility is audited every six months to maintain current certification to verify that their expanded metal products meet the criteria for shortway, thickness and bendability.

“Andrew Mentis has built its reputation over the past 65 plus years for designing and developing products that are suited to the varying demands of the local market. In all instances we subject our product to extremely stringent testing to ensure it is capable of withstanding specified loads without losing its structural integrity,” Quinlan points out.

After pioneering expanded metal products in South Africa, Andrew Mentis has built up a large database of intellectual property and applications experience. The result is a portfolio of products all centred on quality and safety.

Expanded metal meshes are produced by cold-stretching and flattening solid sheets. Even though the original sheet of metal can be expanded by up to ten times its original size, there is absolutely no loss of material during the manufacturing process. This results in a mesh that is considerably lighter than the equivalent area of steel plate.

“In addition, expanded mesh never unravels. When the metal is over-expanded the strands become narrower, the spaces between strands increase and the strength of the knuckle centres in the mesh is diminished,” he says.

The expansion process results in a network of rigid strands which add strength, while simultaneously allowing free passage of light and air. As the metal is expanded to an area longer than its original length it is lighter than the original equivalent mass used prior to expanding. The raised mesh, or Mentex®, can be put through an additional process in which the raised meshes are flattened into the same plane as the sheet of metal expanded, resulting in Flatex®.

“Typically, both Mentex® and Flatex® are manufactured from high quality local mild steel, but can also be manufactured from any other ductile metal. We supply the product unpainted but any of the normal finishing processes such as painting, stove enamelling, plating and galvanising can be readily applied to it,” Quinlan says.

A comprehensive range of sizes, mesh sizes and thicknesses is available and the mesh can be bent, shaped to radii, angled or notched while still maintaining its inherent rigidity. Sizes range from mini meshes, with small openings of 1.4 mm by 2 mm and with a thickness of 0.4 mm, right through to larger meshes with 115 mm by 300 mm openings and a thickness of 6 mm.

In addition to its Mentex® and Flatex® expanded metal walkway products, Andrew Mentis produces a number of architectural expanded metal products including:
• Mentis Angle Bead: provides a true straight-edge for forming an arris in plasterwork which resists chipping or cracking.
• Mentex Expanded Riblath: an effective plaster base for walls and ceilings and permanent shuttering for concrete.
• Mentis Plaster Stop: delivers a straight-edge and finish for plaster at all openings and abutments.
• Mentlath 213: used to provide a key for plaster and as a reinforcement to minimise cracking.
• Mentex Strip Mesh 210: used as a plaster reinforcing along lines of potential weakness such as at the corners of doors and window frames.
• Brickforce: reinforcing in brickwork to strengthen walls.
• Mentex 99 (hailguards): used as hailguards to prevent gutters from filling up with dirt, leaves and especially hail.
The discerning mining, construction, petrochemical, food sectors and general industry commonly use expanded metal for screens, grates, shelving, racks, protection guards, internal partitioning, burglar proofing, fencing, reinforcement, walkways, platforms and stairs, beds, garden furniture, braai grids, filters, dividers, scaffolding, truck bodies, tunnel and shaft linings, grain silos and even decoratively.


Short term financial gains should not outweigh long term safety requirements when it comes to purchasing decision, especially when looking at safety critical purchases such as floor grating.

National technical sales consultant at Andrew Mentis, Lance Quinlan says it is imperative that engineers, architects, specifiers, quantity surveyors and buyers understand the implications of buying inferior floor grating.

“The most important thing to remember is that floor grating is an engineered product, and it is essential that the manufacturing process ensure the final product has the appropriate load bearing capacity,” Quinlan says. “This ensures optimum safety over the long term and must form part of the decision making process. Buying cheap will not only compromise safety, but could result in injury to personnel working in areas where floor grating is used.”

Andrew Mentis has been producing Rectagrid RS40 (40/40) floor grating for more than forty years, and uses a unique compressive pressure locking system, whereby the bearer bars and transversals of the Rectagrid RS40 (40/40) form an exact pitch of 40 mm by 40 mm, with the bearer bars being perfectly upright and without any sideways lean. The locking method at the intersections utilises the full depth of the bearer bar ensuring absolute structural integrity and load bearing capacity.

“Significantly, Mentis Rectagrid RS40 (40/40) has proven itself over years of application in the construction, infrastructure and mining sectors, and for many years has been the benchmark for floor grating,” he says.

Quinlan explains that the manufacturing process guarantees close tolerances are maintained with the round transversal bar fitting tightly through the pierced bearer bar to achieve the superior structural integrity of the product. “This is what customers have come to accept as the benchmark when it comes to quality and load bearing capacity with floor grating, and with our process there are no cracks or crevices at intersections thus eliminating the possibility of corrosion which could weaken the floor grating,” he says.

He adds that because the intersection locking is so positive and strong, it is not necessary to band the grating. Andrew Mentis has, however, gone a step further and it is possible for the panels to leave the rolling mill finished on half pitch all round. This means that panels can be laid adjacent to each other to maintain a perfectly patterned floor with no banding. This is known as the ‘open ended system’. The company, however, also offers customers banded grating and has the facilities to accommodate this.

Andrew Mentis has also extended its range of floor grating to include products with pitches of 45 mm by 40 mm RS40 (45/40), 45 mm by 50 mm RS40 (45/50) and still makes a 80 mm by 40 mm pitch which is known as RS80 (80/40). Stock panels are available in 2.4 metre by 1.2 metre for easy installation or for the customer’s own tailoring.

Rectagrid RS40 (40/40) ensures optimum safety for personnel using the walkways.


When wastewater travels through sewer lines, it can become anaerobic or septic (the dissolved oxygen can become depleted) as a result of the metabolic processes of microbes commonly found in the wastewater. Under anaerobic conditions, specific sulphate-reducing bacteria thrive and generate hydrogen sulphide (H2S) as a byproduct of their respiration.

H2S has a low solubility in wastewater and when it escapes from the wastewater and moves into the air, it is easily recognised by its characteristic offensive, rotten egg odour. It can also be responsible for severe corrosion problems and toxic conditions within wastewater conveyance and treatment facilities.

“Andrew Mentis manufactures a range of corrosion-resistant floor grating and handrailing in galvanised, 304 stainless steel, 3CR12 and fibreglass options that are ideally suited to the extreme conditions found in wastewater treatment plants. All products in these ranges are designed and engineered to suit situations where the strength to weight ratio is important, such as wastewater treatment plants,” Lance Quinlan, marketing manager of Andrew Mentis, points out.

“The water and wastewater industry encompasses the mechanical and chemical processes used to remove pollutants from wastewater, for reuse in the environment. These processes can create a slippery environment for operators and technicians, with vapours, water and chemicals creating slick underfoot and handhold conditions near large machinery and tanks,” he explains.

An emphasis on safety underpins the development of all Andrew Mentis floor grating and handrailing products. “Weakened handrailings and floor gratings, caused by corrosion and damp, can result in slips, trips or falls. In addition, due to the fact that broken handrailing or floor grating needs to be replaced, downtime is incurred, which negatively impacts on productivity,” Quinlan says.

Galvanising or using stainless or fibreglass in a wastewater treatment plant is not only a safe and cost effective option, but it does not compromise the aesthetics of the environment.

Andrew Mentis’ Rectagrid RS40 floor grating is manufactured using a pressure locking system pioneered by the company. The locking characteristics guarantee the structural integrity of the product and further enhance its integrity in a corrosive environment.

“The transversals on the floor grating are positively and permanently locked to the bearer bars and the locking method at the intersections is designed to use the full depth of the bearer bar when calculating loads. This attention to detail ensures that the load bearing capacity is top of mind when design and manufacturing is undertaken,” according to Quinlan.

Andrew Mentis’ stainless steel tubular handrailing is reputed for its corrosion and stain resistance qualities. “We have designed the stanchion base plates to allow moisture to drain from the stanchion itself, thus adding further credence to its corrosion-resistant benefits. These handrails are not only functional, but also resilient and durable,” he says.

The tubular handrailing system is complemented by a range of standard angles and matching accessories, with different bends and end closers adding to the versatility of the product. “Enhanced customer service was a driving factor, with the stanchions and bends forming part of a system of interlinking components that can be installed without the need for special tools,” Quinlan comments.

The stanchions are 42.9 mm diameter by 2.5 mm wall thickness specifications, and are also available in 3CR12 or 304 stainless steel polished to a satin finish.

“Both Rectagrid and Mentis handrailing were selected for the Zeekoegat wastewater treatment plant and other treatment plants in the industry. We believe that each application deserves individualised attention and as such we customise products to meet specific application requirements, within specified client timeframes,” Quinlan concludes.


Stainless steel tubular handrailing still outranks its competitors, and Andrew Mentis confirms that demand for this product remains consistent.

Corrosion resistant and maintenance free, stainless steel handrailing is the first choice in numerous applications including corrosive and damp environments. “This is because it’s aesthetically pleasing and offers scratch and stain resistant properties making it the obvious alternative to traditional mild steel or painted handrailings,” Lance Quinlan, marketing manager at Andrew Mentis, says.

“Weakened handrailings caused by corrosion and damp can cause accidents as well as raise maintenance costs,” he says. “Mentis’ stainless steel handrailings improve safety and reduce maintenance, and by doing so create a more productive work environment. And more importantly, impact positively on profitability.”

Quinlan says Andrew Mentis produces stainless steel handrailing in three alternative grades: 3CR12, 304 and 316 stainless steel. Stanchions are 45 mm in diameter with a 2 mm wall thickness and base plates designed to allow moisture to drain from the stanchion itself, adding to the corrosion-resistant benefits. The centre hole for the knee rail is drilled and then flared on both sides. The top is also flared and a half round cap is welded into place. The base plate is 8 mm thick and welded to the tube.

The clean modern lines are attractive and the stanchions offer a variety of standard angles and matching accessories. Bends and closures common to mild steel systems are also available for this stainless steel system.

Hand-, knee-rail and bends are manufactured from 31.8 mm diameter tube with a 1.5 mm wall thickness. Bends and closures have swaged ends, improving speed of installation and preventing moisture from penetrating into the joints.

All manufacturing is undertaken with an eye to ease of installation, without the need for special tools. The smooth satin finish combined with the selection of grades offers almost unlimited possibilities for interior and exterior commercial applications.


Andrew Mentis maintains that although supplementary building products are not necessarily essential to building work, they are essential to good quality building work.

“The sad fact is that, unless specified in the original job specifications and costing by the architect, there is little chance that a builder would use these products,” Lance Quinlan, marketing manager for Andrew Mentis, says. “We find that architects are often unaware of these products, but once they know about them, they are extremely keen to use them.”

Specific building products, made by Andrew Mentis for the building industry on special purpose machines, are used mainly as reinforcing to prevent plaster and walls cracking and for strengthening the corners of a building to prevent damage where the building is most vulnerable. The products include Angle Bead, Riblath, Plaster Stop, Mentlath, Strip Mesh and Brickforce.

Mentis Angle Bead provides a true straight edge for forming an arris in plasterwork which resists chipping or cracking. The expanded metal wings anchor securely in the full depth of plaster on either side of the arris. “This is essential on plastered columns as the corners are particularly susceptible to damage both during and after building operations,” Quinlan says. Mentis Angle Bead is supplied in 3 metre lengths and is manufactured from 0.5 mm thick galvanised steel strip.

Mentex Expanded Riblath is ideal in the plaster base for walls and ceilings, and as a permanent shuttering for concrete. It has mechanical retention properties for fire protection plasters and splays. The straight, heavy longitudinal ribs and bead stiffening give Mentex Riblath a tremendously high strength to mass ratio.

“It is highly flexible for a variety of applications, yet rigid enough for others. Mentis Riblath has for many years been an approved and preferred plaster base and concrete shuttering material for suspended ceilings,” Quinlan says.

Mentis Plaster Stop provides a straight edge and finish for plaster at all openings and abutments. Recommended wherever a plastered wall finishes against tiles, face bricks, skirting, exposed steelwork, and all woodwork, it protects and reinforces the plaster and gives a neat finish.

Mentis Mentlath 213 is used to provide a key for plaster and as a reinforcement to minimise cracking. It is used extensively for a key where gunite is applied, and is the most accepted means of keying plaster or vermiculite to steelwork when fire proofing a steel building. It is galvanised to prevent corrosion.

Mentex Strip Mesh is used along lines of potential weakness such as at the corners of doors and window frames and as a backing for plaster over narrow gaps such as service chases. “It is used as a plaster reinforcing to prevent cracking around airbricks, window frames, vents, door arches, electrical conduits, water pipes, and is extensively used to provide a bond between dissimilar materials at crack prone areas,” Quinlan adds.

Reinforced brickwork is preferable to unreinforced in all types of building because steel reinforcement adds tensile strength to the inherent compressive strength of this traditional construction method. “Mentis Brickforce 210 reinforcement greatly reduces the detrimental effects of vibration and changes of temperature. Moreover, considerable savings may be made in the cost of material and labour, and in space and deadweight,” Quinlan says.

He further adds that for optimal effect, Mentis Brickforce should be used in every third course of bricks and, where the strips are joined at the ends, an overlap of not less than 80 mm should be provided.

“Embedded in the normal thickness of brickwork joint Mentis Brickforce gives brickwork increased resistance to tensional stresses. This is important for buildings erected on reclaimed ground or on other ground in which settlement may occur. However, it is equally suitable as a reinforcement for concrete block work, partition slabs, asphalt guttering and in other work,” Quinlan explains.

Other items in the Mentis building products range are Mentex Corner Mesh, Mentex 99 hailguards (prevent gutters from filling up with dirt and leaves), Mentis scaffold planks, storm water gratings and frames, and trench covers.