The skills issues of underfloor heating
MIKE LAMB explains why the installation of larger-scale underfloor heating systems is a job for trained professionals.Over the last year or so, there has been an increasing amount of publicity in the Press about the lack of skilled operatives in the heating industry. A rash of training specialists and courses has arisen, with the apparent aim of cashing in on the demand by providing ‘quick’ training in the skills of the plumber and/or heating engineer. The result is a number of so called ‘trained’ workers offering their ‘skills’ to the unknowing public. In reality, many of these people lack most, if not all, of the skills that a proper trade apprenticeship would provide. Remember it takes three to four years to qualify as a plumber with NVQ at Level 3. It is not possible to cram this into a course of three to four weeks, even at £5000 a week! If this is a problem for the heating industry in general, the huge increase in demand for underfloor heating makes it a potential disaster in this sector — where mistakes can be expensive, and real skill is at a premium. The aim of the Underfloor Heating Manufacturers’ Association (UHMA) is to increase the competence of installation engineers to accommodate the extraordinary growth of our industry. The specifier, however, should be aware that intensive training for professionals — which many UHMA members offer — is not the same thing as a crash course for beginners. The results are as different as chalk and cheese. Short training courses for previously unskilled people may well satisfy requirements at a fairly lightweight domestic level. They provide the training necessary to install underfloor heating in conservatories, single room extensions and small refurbishments — under supervision. Commercial sector However, problems start to arise with larger domestic installations and, particularly, in the commercial sector. Here, contractual commitments are extremely onerous, and levels of skill and experience have to be sufficient to meet the needs not only of the underfloor heating but also all the structural elements with which it has to integrate. This makes it essential that the chosen installer company should have a very competent engineering background, with an in-depth knowledge and understanding of boilers, controls, pumps, interconnecting pipework and associated mechanical plant such as heat pumps — not to mention the latest Building Regulations. Unlike any other form of heating, an underfloor system is embedded in the very fabric of the building. Once installed it cannot be modified, altered or removed. It is a wonderfully efficient technology that offers better comfort and lower carbon emissions, but it is important to get it right first time; you are unlikely to get a second chance! UHMA’s concern is that those attending these very short training courses are by no means all experienced mechanical engineers. They have insufficient knowledge of construction detail and no knowledge at all of how the various technologies have to interface. Underfloor heating is not just an associate component in the mechanical plant. Because it is incorporated into the very structure of the building, its structural integrity involves a duty of care far greater than for any other type of heating system. This is particularly important in commercial projects where the underfloor heating package often has to interact with a number of other disciplines. Issues that may need to be resolved include the following. • Screed type, depth, strength and performance. • Floor finishes and the effect they will have on the thermal performance of the system. • Applied point loads to the floor. • Insulation thickness and strength to meet Part L of the Building Regulations and the applied loads. • The new Part E regulations on acoustics and the effect that the underfloor heating would have on these. • The construction zone available to accommodate these requirements. •The various structures that the underfloor heating can be incorporated in: pre-cast; post-tension; floor slab; pre-cast beams and any number of various types of floor screeds. The drive for ‘greener’ buildings means that underfloor heating and cooling is increasingly being considered as a viable alternative to air-conditioning. The same pipework matrix that heats the building in the winter can circulate chilled water during the summer to create cooler, more comfortable conditions. Simultaneous heating and cooling of different parts of the building to cope with solar gains is also perfectly possible. It is a cost-effective and environmentally friendly method of cooling. Many systems utilising this technology have already been installed. Unlike underfloor heating, which is generally a fairly straightforward process, underfloor cooling requires a higher degree of engineering skill, which can be fairly easily acquired by experienced mechanical engineers, but is likely to be beyond the capabilities of the novice. In-house expertise When you are considering a company to undertake a sizeable domestic or any type of commercial project, you should turn to an organisation that has the right level of expertise in house — one that can offer a truly comprehensive service up to and including commissioning and has a proven track record in the field. Increasingly, mechanical-services contractors and builders are looking for competent underfloor-heating contractors with all the necessary insurances, guarantees and skills to undertake packages that incorporate not only the underfloor heating, but also, the screeding and the thermal and acoustic insulation. In reality, there are only a very small number of companies that can offer this level of comprehensive service at competitive rates. Some companies may choose to use specialist sub-contractors, but this leads to the problem of responsibility for the various elements should anything go wrong on the project. A recent ruling by the courts would seem to indicate that responsibility cannot be devolved down the contractural chain. Everyone has to start somewhere, but a large-scale underfloor-heating system is not the best place! Mike Lamb is chairman of the Underfloor Heating Manufacturers’ Association, 47 Byfleet Road, New Haw, Surrey KT15 3JS.