Page 26 - Parquet International December 2013

ON FIELD
The photographs show the surface after a game.
A SURVEY
move randomly across the surface of a floor. The only common element was that the gaps between the boards were gen- erally found at either end of the court, near the baskets, i.e. the areas most sub- ject to stress and pressure, where the ath- letes concentrated their efforts.
We were asked to investigate the matter in order to understand the origin of the defect and, of course, solve it.
In search of a cause
The owners had started to raise objections as early as the final testing of the newly laid floor. Their first few letters had, in fact, pointed out that “the parquet sports floor has problems regarding gaps ap- pearing between the boards both length- wise and transversely.” This problem had also been reported by the various sports clubs using the sports hall.
These reports were accompanied by pho- tos showing the areas of the court near the baskets, clearly showing that the po- sition of the gaps between the boards changed each time.
Meanwhile, the floor fitters rebutted with the claim that the gaps were due to the ex- cessive temperature of the radiant panels in the floor heating system, but after an audit by a technical expert appointed by the owners, it emerged the temperatures posed no risk to the stability of the floor: • Parquet surface temperature
= max 25.6 °C and min 25.2 °C.
• Parquet temperature where covered by
the PVC platform = 26.9 °C
• Air temperature under the floor
= 23.4 °C
Other abnormalities then emerged, which, although not actually rendering the floor unusable, did affect the aesthetics: the
ends of numerous boards were virtually right up against each other, meaning there was no offset distance between them. The presence of shrinkage or cracks along the longitudinal side of each boards was also noticed, which was in turn composed of individual layers of parquet, although there were no particular anomalies in the size of the boards.
In essence, the shrinkage was minimal and in line with the physiological be- haviour expected of wooden flooring on a heated substrate.
However, the flooring had been raised above the heated surface by inserting wooden blocks (“sleepers”) and load- bearing joists upon which the parquet rested. In other words, joists (double os- cillation) had been placed on these wood- en blocks, followed by a second decking layer (the counter floor) and finally the fi- nal wooden flooring. Furthermore, two polyethylene sheets had also been laid: the first under the heating system pipes between the bottom surface and the base of sleepers; the second between the counter floor and the individual parquet boards making up the sports floor. Another important factor was that the wood used had all the necessary certifica- tion, namely DIN V 18032-2:2001-04 dat- ed 28-02-2005 by DIN CERTCO in Berlin. After taking into account the findings of these technical investigations, it became clear that the work had been carried out without taking into account the manu- facturer’s technical requirements, thus compromising the warranty of the prod- uct itself, since it could no longer respond to the basic requirements for which it had been approved.
Moreover, it also emerged that the in- stallation instructions, which indicated the size of the nails to be used as well as other obvious technical matters, had been ignored. In fact, the movement of the end boards and their continuous change in position made one think that the problem lay in the anchoring method rather than being connected to the heating system. It therefore became necessary to proceed with an invasive investigation in order to verify the presence or absence of the an- chor nails and their size, given that these were required in the technical documents accompanying the product. R