General Information
Batten floor underfloor heating systems, are designed to be incorporated into floor constructions that use timber battens laid onto an existing floor finish. There are various methods for installation but the overall result remains the same. The batten floor system does not use any kind of screed or concrete to conduct the heat but instead relies on heat transfer plates to disperse the heat. These systems are very commonly used in situations where real or engineered timber floors are to be laid as the finished floor. The addition of the batten, allows the finished timber floor to be fixed using a traditional secret nail method of installation.
Batten floors require the space between the battens to be filled with insulation once the underfloor heating has been installed. This prevents heat loss either into the void created between the battens and /or to the floor below.
A heat transfer clip is fixed on the top edge of the batten, to provide a cradle for the underfloor heating pipe work to fit into. At this stage, the clip is separate from the aluminium conducting plate which can be positioned freely to match your underfloor heating layout. The Robbens system allows the installation to be freely adapted into most batten spacing’s. The typical spacing is approximately 400mm, although if the spacing varies between battens, then the separate clip and plate combination allows you to adapt the installation easily as you fit it.
Once the pipe work has been installed, the insulation fitted, and you are ready for the floor deck to go down, lay the aluminium conducting plate across the top of the joists. This plate connects all of the heat transfer clips and draws the heat away from the pipe work and disperses it across the floor, to provide an even floor temperature. The final stage before the floor deck is fixed down, is to lay a lightweight polythene sheet across the top of the aluminium plate; this is refered to as the vapour barrier.
Before the pipe work is covered with the flooring and aluminium sheets, you have to fill the system with water and pressure test it. This test will determine that no damage has occurred to the pipe during its installation, and can be monitored during the finished floor laying stage to check for damage, should it occur.
Insulation
The insulation depth varies between projects. Building regulations will require a specific amount of insulation to be used. This will usually be more than the underfloor heating requires and therefore not be a problem. In most situations, a 50mm batten infilled with PIR insulation is normally used, but other less efficient insulations may require deeper battens to accommodate additional insulation.
Batten floors require the insulation to be a 'full fill' between the battens, and should be tight up against the underside of the floor deck and underfloor heating. As long as there are no voids either below the floor deck or underfloor heating, you can use different types of insulation to achieve this result, which ever suits your build best. You should always check with building regulations and insulation suppliers regarding specific requirements for your project.
Build Up Heights
Batten floors can increase the floor height, this usually being dependant on the amount of insulation used. If for example you use a 50mm PIR insulation to fill between the battens, the batten would therefore need to match the insulation thickness, in this case by 50mm. The height build up for batten floors is generally quite low compared to solid floors, and can often be the perfect compromise when considering underfloor heating in renovation projects. In a new build, the increase in floor height can be designed into the building at a very early stage.
Temperatures and outputs
Batten floors have a limited output compared to screed systems, although this output should be more than enough heat for modern well insulated buildings. Even though their outputs are lower the water temperature required to run them is higher, normally around 55 – 60c. This specification will allow the system to produce 70w/m2 with a maximum surface temperature of 27c.
In a modern building with high levels of insulation and modern high specification double glazing, the floor temperature is usually within a few degrees of the air temperature in the room, providing a warm and comfortable enviroment even during very cold weather.
If you have a poorly insulated building with little or no insulation, draughty single glazed windows, and open flues you will find that the system will have to work considerably hard to achieve a comfortable room temperature in cold weather. We recommend you always refer to the heat loss calculations that are prepared at the quotation stage, to ensure that these issues are highlighted as early on in the project as possible.
