Fitting Underfloor Heating in Old Homes

We love underfloor heating. It makes a big difference in creating a constant and comfortable inside temperature so we always recommend it when we do big refurbishment projects.

However, on smaller projects where the work we do is mostly superficial, it's not such an easy option. Retrofitting under floor heating takes much more thought and planning. You could connect just a single zone of UFH to your existing heating system, but this does not offer as much control over the temperature - the UFH can only be on when the rest of the central heating is on. UFH takes longer to heat up than radiators, so the area with UFH will remain cold whilst the rest of the house warms up.

For a retrofit, UFH should ideally operate on a separate zone system with direct boiler control. T do this, you could separate the flow on from your boiler primaries so that one set of flow and return goes to your radiators and the other to your UFH system. An alternative would be to choose a system such as OneZone from Nu-Heat, which can be controlled individually.

The type of floor also needs to be taken into consideration. In new builds, pipes are usually fitted into screed floors which are being laid at the time anyway. In older, homes, on the other hand, the best way to retro-fit UFH would probably be to add a floating floor over your existing structure to accommodate the UFH pipes.

The downside is that this will add to the floor height (therefore, reducing your overall room height). This is a big enough problems when fitting UFH on a new build or total renovation but it can create a whole new headache in retro fit situations. Existing skirting boards will have to be removed and it will affect your doors, which may need to be re-hung to open smoothly over the new floor, or to have some of their height taken off.

If you are working with a suspended timber floor, and do not want to add to your floor height, it will have to be removed and the pipes laid underneath, usually between joists and on top of insulation, in order to maximise efficiency, but this can be a bit more disruptive.

Luckily, there are a number of companies that offer systems specifically for retro fit designed to be fitted in the least disruptive way possible and to raise the existing floor height by as little as possible, usually around 30mm. Good companies to look at are Nu Heat systems, Ippec's Pexatherm Thin System, the Schulter-Bekotec-Therm, Polypipe's OverlayTM Lite and Robbens System's Single Room UFH Pack.

With so many new companies offering affordable and innovative solutions to the retro-fit UFH problem, getting rid of your radiators isn't such a far off concept as it used to be. Ardesia Design uses and recommends the Polypipe OverlayTM system.