• Inappropriate installation of wood flooring can lead to costly remedial work.
• Available information is lagging behind rapid advances in product technology.
• It is essential to understand how wood behaves.
TRADA has produced a guide to flooring installation.

Short cuts and inappropriate installation practice in the wood flooring sector can cost the contractor hundreds of times the initial saving to put right. In these times of growing financial insecurity, can one really afford to shell out money on putting right faults which have occurred through bad practice or lack of knowledge?

In our experience, the majority of floor failures are down to a lack of understanding of how wood behaves in service and how these dynamics are inextricably embedded into recognised good practice guidance for installation. However, one can also sympathise with installers. This problem is not always of their own making, but is often exacerbated by market developments.

The information available to installers is, at best, fragmented and, at worst, fails to reflect current advances in flooring manufacture. At least part of the reason for this is that innovations in product technology are advancing at a rate which is increasingly out of step, apparently, with established doctrines of best practice.

Recognised practices

I have been reminded of this while working on the new TRADA guide, which offers a one-stop shop guide to wood floor installation. It brings together recognised installation practices and explores some of the technical and practical principles behind them.

There are two prerequisites for best practice: an understanding of how wood behaves as a floor-covering material and technical knowledge of its limitations.

It is only thus armed that installers can ever hope to be prompted into actually thinking about why certain techniques and approaches are recommended and what is likely to happen if they are not implemented.

I was made aware of the fact that accepted installation protocols are being blurred at the edges when a draft of the guide was circulated to a number of expert bodies for comment and feedback. It was immediately clear that, in some areas, there was relatively little consensus on some of the finer points of installation practices. This was unheard of several years ago when the technology of wood floor coverings was less sophisticated. My conclusion is that rapid developments and sophisticated product innovation seem to be blurring opinion as to what guidance actually holds true.

Wider boards

A very basic example of this is found in the tendency of suppliers to import increasingly wider dimensioned boards – up to 200mm or even greater – often without providing the necessary back-up by way of appropriate installation guidance. For example, if the board dimensions are 200x20mm, what strategies are available to the installer to prevent distortion in the form of cupping or, for that matter, what provisions should be adopted to allow for lateral movement? Does he attempt to minimise the likelihood of cupping by selecting quarter-sawn material (impractical and expensive) or does he acclimatise the boards exactly to the ambient conditions expected in service (almost impossible to enforce the required degree of stability.

The problems don’t stop there. What if the boards are to be stuck down? What glue does he use to minimise the potential of movement? And, having selected the adhesive, what preparatory measures of the sub-floor and application techniques does he adopt? Or does he go for the prudent approach and specify a board with a more realistic aspect ratio to begin with?

Expert advice

In such a situation, installers often turn to the experts and are confronted by a number of informed opinions, each of which may have a sound technical basis but may differ in their practical outcome, depending on how the problem is presented. It is then left with the installer to select whichever advice he feels most comfortable with (which may not always equate to the right approach).

These questions can only be answered through a fundamental technical understanding of how wood behaves. The TRADA installation guide has been written to bring all the accepted guidance together, as much for the technical community as for the installer. It is hoped it will serve as a benchmark for installers and help demystify the process of specification and product selection for the benefit of the industry.