Trada Launches Test Rig For Underfloor Heating
Peter Kaczmar, wood floor specialist at TRADA, reveals that a new research project to develop an underfloor heating test rig for wood flooring has been launched by TRADA:
WHEN it comes to floorcoverings, nothing quite matches the performance and beauty of a wooden floor.
Whether it’s engineered, multi-layered or solid, a wood floor can lend a different dimension to a space, with an aesthetic that other floorcoverings find hard to match. This is why timber continues to grow in popularity as a flooring material in both the residential and commercial sectors.
Timber has a natural warmth to it, but, with developments in underfloor heating (UFH) systems, its use alongside these developments has, on occasion, caused problems. Wood is a dynamic, breathing material and as such can be prone to excessive movement. Even without an UFH system, a wood floor is constructed with room to move: add heat into the equation and the problems can be exacerbated.
Following initial feasibility studies, TRADA commissioned a research project to develop an underfloor heating test rig for wood flooring. The construction of the rig was designed to enable new designs of floorcoverings to be tested (such as bamboo, modified wood etc) as well as being able to assess the suitability of different multi-layered floor systems.
There’s no doubt that manufacturers of wood floor coverings are increasingly pushing the boundaries of accepted practice in their approaches to aspects of flooring design and installation.
Floor systems intended for UFH are increasingly being installed in widths traditionally considered as oversized for such installations.
In its research work, TRADA has also found that composite floor materials, with a hardwood veneer on a plywood base, are particularly prone to splitting because of the mismatched movement characteristics when exposed to conditions that promote drying.
The increase in popularity of UFH systems has been associated with a corresponding rise in the incidence of in-service shrinkage, cracking and distortion failures; as a result, there is a need to test new flooring systems with UFH to verify manufacturers’ claims.
TTL has increasingly found itself called in to deal with legal disputes over wood flooring failure – and this was the main driver behind the development of the test rig.
In particular, the rig was also designed to enable appropriate initialisation protocols to be identified for different makes of floor product – including alternative materials like bamboo and modified wood products – and enable controlled testing under a range of specific operating conditions in order to identify realistic operational parameter ranges.
It is expected the rig will provide a facility to:
n enable comparative testing of flooring with different constructions eg (multi-layered vs engineered vs solid etc) used with UFH;
n enable the testing of boards of different widths over UFH;
n enable the testing of the propensity of different species (including bamboo and modified wood substrates) to exhibit splitting when used over UFH;
n enable the testing of the dynamic behaviour of wood floorcoverings when subjected to recommended UFH initialisation protocols;
n commercial products; and
n enable new research to be conducted on the adequacy of UFH initialisation procedures and schedules.
Requirements for the research: The industrial perspective: There are a number of issues involved in using wood as a floorcovering with an UFH. Firstly, no standardised guidance on initialisation regimes are provided to the consumer.
Recommendations from manufacturers often differ from advice given in Standards guidance. Empirical research is necessary in order to verify alternative protocols and prevent flooring failures during or immediately subsequent to the use of the underfloor heating system.
Secondly, concerns have been expressed by some sectors of the industry that UFH systems heated with electric floor matting have a much greater tendency to trap heat beneath carpets and floor rugs laid onto the floor than hot water systems because of their inability to dissipate excess heat. This is currently the main reason why water-ducting is the preferred system of UFH installation effected by the industry. Research to verify the practical significance of these claims is required.
There is also concern within the wood flooring sector that wood flooring products of questionable quality are compromising the reputation of wood as an acceptable floorcovering for use over UFH systems insofar as the incidence of failures has often been linked with products of inferior quality.
The proposed floor test rig will enable a method of experimentally verifying the acceptability of a commercial product for use with UFH systems.
The use of alternatives to solid wood substrates such as multi-layered flooring, modified wood (Accoya, Thermowood etc.) and bamboo (including variant forms such as strand-woven or carbonised bamboo) are increasingly being specified for flooring.
However, virtually no empirically-based information is available for these variants which can endorse their use with UFH systems.
The development of an UFH test rig will enable the means to provide authoritative independent guidance on these issues based on judgments made from empirical studies and will allow a range of potential problems to be investigated.
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This article has been reproduced from the Contract Flooring Journal website. You can find them at www.contractflooringjournal.co.uk.