A hot topic

A hot topic

Just as no two jobs are ever the same, there is no one-size-fits-all solution to underfloor heating. With such a wide range of products available, it can be hard to know where to begin when advising on and installing the perfect system. James Bell offers his advice on underfloor heating, from planning through to installation.
Underfloor heating has risen in popularity and as such, installers have seen an increase in demand from homeowners not only asking for systems to be fitted but also for the best advice on product selection.
Preparation and planning
Preparation and planning is key when installing underfloor heating, as small considerations can make a huge difference to how effective and efficient a system is in the long run.
Before offering advice or making any decisions, chat to the homeowner about what they are looking for from their system, including which room(s) they’d like underfloor heating in. Underfloor heating is not a one-size-fits-all solution. There is an option to suit any room, floor type and floor covering, meaning it’s possible – and important – to select a system that is tailored to each project.
Underfloor heating systems will work efficiently with any floor covering – from carpet and vinyl though to laminate and stone – as long as it is well insulated underneath. However, each covering has different thermal conduction properties – for example, harder surfaces offer better conductivity and therefore better heat output rates, so it’s worth considering all the options.
System selection
The following are the most commonly found systems in the UK market:
• Solid floor – Perfect for installing underfloor heating into solid or screeded floors. Suitable for all floor coverings, solid floor underfloor heating is most commonly used in block and beam construction and can be installed in new builds or renovation projects.
• Suspended floor – For use in timber suspended or battened floors, these systems suit new build projects best. Although, most commonly fitted from above, recent product developments mean that it can now be fitted from below, allowing the system to be used even if the floor above has already been installed. A layer of insulation below the panels ensures that almost all of the heat generated passes to the room above.
• Floating floor – designed for use in applications where a solid floor installation is not possible because of structural weight limitations, or where a ‘dry build’ floor option is necessary. Suitable for use in both newbuild and existing properties, floating floor panels can be installed directly above solid and timber floors.
Alongside the above, Polypipe has also introduced several unique systems to offer even greater choice to installers.
– Polypipe Modular Heating Panels – A new product concept enabling quick and simple installation of underfloor heating into suspended floors. The system consists of pre-configured panels that are connected together on site during installation, simplifying the process – especially when installed upstairs.
– Polypipe Overlay and Overlay Lite Systems – A unique low profile floor heating system, ideal for both renovation and new build projects. Installed over the existing floor and measuring just 18mm in depth, Overlay allows floor heating to be installed where traditional underfloor systems would either require expensive and extensive excavation or would need the floor to be raised to an unacceptable level. Overlay Lite is ideal for use with laminate, engineered wood and carpet because it is a high compressive strength, lightweight insulated panel
Top tips for installation
Installation methods vary among manufacturers, so check the details of the system before proceeding. Thankfully, there are a few common practices and tips that apply across-the-board that installers should be aware of.
• Installation preparation
Although this sounds obvious, it is absolutely imperative that the sub-floor is swept clean and is free from mortar residues before installation can begin. Failure to do this may leave the surface uneven and could lead to long-term system damage.
• Tricky layouts
For awkward shaped or split level rooms, layout difficulties can be overcome by using a water-based system incorporating polybutylene pipes – plastic pipes that can circumnavigate sharp angles or unusual wall shapes.
• Manifolds
A manifold should be used to control the flow of water through an underfloor heating system, and will be required for all systems above 30m² in size – regardless of the system selected. With particularly large installations, it may be that more than one manifold is required.
The location for the manifold should be agreed prior to the work being undertaken, taking into consideration the location (room) of the heating system and boiler, as well as aesthetics – ideally, the manifold should be out of sight.
• Temperature control
Depending on the application, a programmable thermostat can allow independent time and temperature control in each room or zone, maximising both comfort and efficiency for the homeowner.
Furthermore, because the surface area of a floor is large, underfloor heating does not have to operate at the same high temperature as a radiator-based system in order to emit suffi¬cient heat to make the room comfortable. Polypipe offers a range of water temperature control units, which can be used to reduce the water temperature for underfloor heating systems, when connected to the same boiler as used for radiators or stored hot water.
• Multiple room installations
Several circuits and careful planning are needed for multiple room installations, particularly in areas close to the manifold, in order to allow for all pipes to be accommodated. Admittedly, this sounds like a planning nightmare. To help with this, remember that pipes can simply go through – rather than around – walls to eliminate how many pipes require access to the manifold.
• Connecting to the heat source
It is vital that the manifold(s) for the underfloor heating is/are fed directly from the heat source via dedicated flow and return primaries. These primaries are what enable total independent hydraulic control of the underfloor heating system when it is in use.
Solid fuel or wood burning heat sources should never be used in direct conjunction with underfloor heating. Instead, use the burner to provide indirect heat via a thermal store or similar neutraliser. The low temperature feed from this store can then be pumped to the underfloor heating manifold. Heat pumps are an ideal heat source for use with most underfloor heating systems because of their lower operating temperatures.
As underfloor heating is new to many customers, proving your expertise and providing top quality customer service is an excellent way of gaining positive feedback and generating word-of-mouth recommendations – the best marketing possible.