The most important and potentially troublesome element of warehouse construction is the concrete floor, yet it is likely to be the most neglected and most abused, leading to a host of problems down the line, some of which could be nightmarish. The reasons for such cavalier neglect and abuse are probably well-known to many but they bear repeating because some of them can be ameliorated at the start of a new warehouse and none is really excusable.
On a descending order of importance, typical reasons for neglect and failing to do repairs promptly include: 1) No time for repairs, 2) Inadequate maintenance manpower, 3) Not corporate priority, 4) No money in the budget, 5) Lack of training/knowledge, 6) Cannot tolerate dust and noise during repairs.
One recent survey revealed that six out of 10 buildings had floor problems, most often because the floor was made on the construction site subjected to variances of temperature and other conditions, inexperienced work crews and poor quality control during and after manufacture.
So just how badly can things go wrong through neglect and what can be done to design them out at the new-build stage or retroactively apply good remedial measures?
Typical floor problems include:
1) Base slab concrete or sub-grade conditions that produce floor cracks and rocking slabs,
2) Surface dusting from uneven dusting or preventative wear,
3) Joints which break down or are difficult to repair,
4) Misapplication of floor-surfacing materials, for example, using light duty floor surfacing materials instead of moderate or heavy duty and applying non corrosion resistant surfaces instead of corrosion resistant.
The common problem of joints cracking up can be avoided or reduced at the new-build stage by choosing a ‘jointless’ SFRC slab without troublesome saw-cut joints or saw-cut induced contraction joints. The fewer the number of joints in a floor slab the better will be the operational efficiencies and floor and MHE costs.
If one finds preliminary soil testing and proper compaction of earth have not been done, leading to dishing floors, there is now a much cheaper remedy than pile driving or tearing down the whole building. Ground penetrating radar offers a cost-effective way of assessing concrete slabs and identifying defects in construction and possible causes of failure. If the subsoil conditions reveal serious voids behind the floor dishing then pumped foam injection techniques like that from Uretek can achieve a levelling accuracy of 1:1,000. Other forms of uneven floor flatness can be remedied less disruptively by laser grinders provided by the Cogri Group.
The issue of floor neglect, combined with abuse, that midwifes sanitation issues in food environments can be disastrous.
Cracks in concrete harbour dirt and debris and most sweeping machines cannot remove dirt from deep cracks. Scrubbers leave moisture in floor crevices, a breeding ground for mould, insects and mildew. Large cracks can allow rodent entry. This may not sound disastrous but consider one restaurant food supplier who suffered intolerable rodent and insect infestations. The underlying problem was the faulty new floor which allowed fresh food and other products to accumulate in the floor cracks and joints. The warehouse operator sued the contractor to replace the whole new warehouse because the floor was faulty.
Fortunately, Britain has a mature specialist flooring industry buttressed by the Association of Concrete Industrial Flooring Contractors (ACIFC). Practically all UK warehouse floors are designed to TR34, the Concrete Society’s design guide. This protects the building owner and tenant but building owners should ensure that their performance specifications are designed and tested to TR34.
Comments are closed.