Dave Rayner, Polypipe’s product development manager for UFCH, enthuses over a system that can be installed quickly without major disruption
THE vast expansion in the use of underfloor central heating during the last few years comes as no surprise to anyone in the business. The advantages of underfloor systems over radiators are many and manifest; evenly spread warmth without hot spots, uncluttered walls easing interior design and the elimination of the radiator convection currents that circulate dust particles.

These are but a few examples. Above all, warm floors are loved by everyone from elderly people suffering cold feet through poor circulation to toddlers and small children at play and even to dogs taking their ease at their master's feet. What has bothered householders looking to specify underfloor central heating however, especially in refurbishment and extension situations, is the delay and chaos that can be caused during installation.

They need worry no more for, with these often justifiable fears in mind, Polypipe has developed and introduced the Polyplumb Overlay System. This quickly and easily fits over virtually any flat surface with minimal domestic disruption.

Overlay's great advantage is that the system's pre-formed, high load bearing floor panels are only 18mm deep and that they can be laid directly over an existing floor, be it of concrete or boards, without any structural work.

The panels are easily cut or sawn to the required shape and once these are down it is simple to 'walk in' the ultra-flexible polybutylene pipe into the panel grooves from a large roll.

The 12mm pipe adapts easily to the tight bends often required in UFCH design and once installed, thanks to the advances in plastics technology, there it will remain maintenance-free over a long lifetime.

Laminate or tile flooring can be laid directly on to the Overlay panels. If a vinyl or carpet finish is required then an intermediate plywood layer is recommended. It is all very simple but very effective! A compact Zonal Regulation Unit (ZRU), converting the temperature and flow rate of an existing water heating system to those suitable for Underlay, allows the system to run happily in parallel with radiator heating in other parts of the home - particularly useful in the case of extension work, loft conversions or conservatories.

Two recent case studies of homes choosing to use Overlay may help to underline the advantages of this versatile system. The first is the Grade 2 Listed Blyton Mill in Lincoln, built as a windmill in 1825, later converted to steam power and then to an electrical drive system that ran until the 1960s.

Although the sails are gone, the building retains great charm and many of the original features. The present owner, Gareth Hewitson-May, decided to turn the mill into part of his home with the ground floor (circular with a diameter of seven metres), a living room and the first floor (six metres diameter) an airy studio.

Clearly, lack of flat wall space made radiator heating impractical, expensive and in any case out of character with the room.

Gareth equally feared that a ufch installation in such an old and oddly-shaped dwelling would be a long and disruptive process but in consultation with Pennine Underfloor Heating, he discovered a quick and practical solution in Overlay.

The ground floor installation was over a concrete floor and plumbed into the existing oil-fired heating system while the panels for the studio were laid on a timber floor and fired by a small electric boiler. Installation was completed in a remarkably short time and with excellent results. The other example is the major refurbishment of a detached house in Crosspool on the outskirts of Sheffield, undertaken by the owner David Wilson Wolfe.

Central heating was required in the concrete-floored kitchen and in the new 'wet room' extension outside it but with the kitchen fully fitted and the wet room containing a corner shower unit and patio doors, there was no wall space left for radiators. David was on a tight schedule and, with brand new units already in his kitchen, he was appalled at the thought of the time and mayhem that would result if he had to lay a screeded floor for conventional ufch. Once again Overlay proved ideal for the situation. Installation was completed in half a day and David was able to lay a tiled floor over the panels the same evening. Both rooms were controlled by a single ZRU and the system was simply plumbed into the boiler powering the radiator system for the rest of the house. Since David's home is due to be featured in an ITV series 'Don't Move, Improve' Overlay may well get star billing.

Obviously I am biased on the subject of this simple, speedy and efficient ufch system but I am convinced it provides an easy solution, sometimes the only solution, to many heating problems. I trust that the examples quoted here will help to prove the point.