Some owners and occupants of new high-bay warehouses are concerned to find the pristine appearance of floor surfaces becoming blemished by black marks that resist cleaning. Grant Roe, BE(Hons) MEngSc MBA MIEAust CPEng NER, explains why this common problem is often misunderstood and prescribes the appropriate solution.
There can be technical misunderstandings behind trade-level advice as to what causes black marks to accumulate and persist on the surface of new warehouse flooring. Due to these technical misunderstandings, ineffective remedies can be recommended with well-meaning intentions but unsatisfactory results.
Costin Roe Consulting is one of the world’s leading engineering firms in high-bay warehouse design from both civil and structural engineering perspectives, and winners of the ACSE NSW Award for Excellence in Structural Engineering for work including the high-tech concrete pavement at Veolia complexes in Woodlawn and Banksmeadow. Europe has led the world in high-bay warehouse design and automation. Each year, the firm’s Managing Director, Grant Roe, spends time in Europe examining the latest developments in high-bay warehouse engineering, and in Australia, he is acknowledged as an engineering expert engaged with numerous successful high-bay warehouse design and construction projects. A recent Q&A session with Grant Roe, on the topic of warehouse flooring, delivered the following explanations and recommendations for warehouse flooring maintenance where cleaner appearances are required.
Cause and effect determined through physics and logic
The curing compound used in the concreting process, to achieve greater precision and efficiency, is often blamed for the ongoing accumulation of undesirable floor markings. In fact, the curing compound is formulated for rapid break-down and dissipation. “Any effects from the curing compound are gone after six to twelve months. So, whatever its contributing factor may have been for a brief period following construction, people are finding the black marks keep accumulating and resisting all the usual attempts at cleaning and preventative treatment,” Grant said. With the curing compound dismissed as the prime suspect, the discipline of engineering looks objectively at the forensic evidence and the science at work behind evident factors.
“When rubber tyres are rolling normally over warehouse floors there is no problem. However, new warehouse flooring offers less friction for tyres to maintain traction and keep rolling normally. When reduced friction causes loss of traction, the tyres slip and slide, and the rubber can heat to the point of burning. The slipping and burning actions leave behind carbon and rubber residue, appearing as black marks on the floor,” said Grant. “The problem has become more apparent in recent years because forklifts have been modified to become more powerful, the wheels are smaller in diameter, and more energy is being applied at the interface. It’s a worldwide issue, as similar concerns have been raised and solutions sought in other countries for some time.”
Grant went on to explain that white tyres had been tested as an alternative but the white rubber was found to be not as durable. Since black tyres last much longer, and perform better for heat absorption, changing to white tyres for cosmetic reasons would not make sense commercially. Yet, for some warehouse operators, aesthetic appearances will matter almost as much as performance. This is where engineers can more accurately identify the cause of problems and prescribe the most efficient means of achieving the desired aesthetic result.
Floor densification treatment the answer for increasing friction
The answer to persistent black marks on new warehouse flooring, as explained by Grant Roe, is simple, practical, and readily available in Australia.
“Floor densification is a good solution, combined with controlled surface grinding. Although this approach may sound counterintuitive, increasing the friction, and thereby minimising the loss of traction, are the keys to resolving the problem. When properly executed, the grinding modifies the surface and combined with the densification treatment, the friction properties of the floor surface are changed. The densification treatment also serves as a surface sealer, providing easier removal of any tyre markings that may occur. This combined grinding and densification treatment is used quite widely in Europe but not so much in Australia where the products and trade-skills are available but the prescriptive expertise is still emerging,” said Grant. “The answers I’ve given today are intended to assist local building owners and maintenance service providers.”
For specific assistance with new warehouse flooring projects and any remediation or maintenance issues, call Costin Roe Consulting on 02 9251 7699.