Underfloor Heating Screeding
In trying to find an even and comfortable heat for their homes and buildings, many people are now opting for underfloor heating. Having a source of heat at floor level ensures an even surface temperature throughout the entire room and avoids any wasted heat at a high level. They can also be beneficial in minimising the drafts that would normally occur at floor level and that could affect the temperature of the entire room.
We would recommend the services of Fast Track Screeding. This Berkshire based construction firm has over twenty years’ worth of experience in a variety of screeds and their applications and is at the forefront of this modern and effective method of heating.
Underfloor heating is a reliable and efficient method of heating an entire room from the floor upwards. It is essential that it is fitted properly, and part of a successful installation process involves embedding the pipes into the layer of floor screed.
Underfloor heating can be powered by a variety of common heating sources including gas, oil, solid fuel, or water condensing combi-boilers, although the current crop of combi-boilers ensure the most efficient source and method of heating.
Underfloor heating can be provided by either water or electrical systems. The two look very similar in appearance but the difference is that in a water system, pipes carry hot water as the source of heat, whereas in the electrical systems, the electric cable is the source of heat.
Underfloor Heating Systems
A huge benefit of either form is that both are energy efficient. Water-based underfloor heating uses water that is heated to a lower temperature than that of traditional radiator heat (50 degrees as opposed to 60 degrees), and these lower temperatures mean that under floor heating is much more suitable for use with ‘green’ energy measures such as solar panelling.
In order to get the safest and most efficient method of heating, it is always recommended that underfloor heating is fitted by a qualified and skilled professional and that this professional takes into account the surrounding materials. Alternatively, underfloor heating screed may only be appropriate for certain types of floor and building, although it is nearly always used in new buildings and modernisations.


Underfloor Heating FAQ's
Yes, Ardex screeds are completely compatible with underfloor heating and are recommended in these types of installation, as this is where the quality of Ardex products shines through!
IMPORTANT: Underfloor heating must NOT be turned on until the screed has been allowed to dry completely, so this is where fast-drying Ardex products are a god-send, particularly in cold weather! When using Ardex products, underfloor heating can be commissioned after as little as six days.
Top Rated – Ardex A23
Drying time: 6 days
- Fix Ceramic Tiles after 48 hours
- Fix Natural Stone Tiles after 3 days
- Fit Carpet, Vinyls or Wood Floor Coverings after 6 days
- Pumpable for fast application and tight access areas
- Commission your Underfloor Heating after 6 days
- Save Two Months on your over all Build
- Coverage: 1:7 mix = 0.27kg/m²/mm
Top Rated – Ardex A35
Drying time: 24 Hours
- Ready to walk on after only 3 hours.
- A35 is ready for ceramic and natural stone tiles to be laid after only 24 hours.
- With A35 you can install carpet or vinyl floor coverings after as little as 4 hours, when smoothed with Ardex A55
- Pumpable screed for a quick application. Reducing the overall time of your project
- Commission your underfloor heating after only 3 days
Top Rated – Ardex A38
Drying time: 48 Hours
- Ready to walk on after 3 hours
- Lay ceramic and natural stone tiles directly after only 4 hours
- Install wood, carpet and vinyl floor coverings after 48 hours
- For internal and external use, including wet and submerged areas
- Pumpable for fast application and tight access areas
- Commission your underfloor heating after only 3 days

The client or main contractor, should be aware the underfloor heating must not be turned on to dry the screed until the screed has been allowed to dry and cure in accordance to the product data sheet provided by your chosen screeding contractor.

So people often find they have a 100mm of screed to lay and realise that they have well in excess of 100 days of drying time to wait before they can lay any floor coverings and turn on there new underfloor heating system.

The British Standards (BS 8204) states with Traditional Screeds, you can apply light foot traffic after 48 hours, then cure with polythene for a further 28 days.
The problem with using the polythene curing system is that normally on going trades remove it in some areas which contaminates the screed and starts causing it to break down.

Often Clients have a Standard Traditional or Liquid Screed installed, then realise the Screeding Contractor they have used, has not informed them about that the Screed needs to be dry before any Floor Coverings can be fitted.
Many projects require fast turnarounds that minimise downtime and disruption.

The main reason many people now use Ardex products is peace of mind. Let’s face it – building and renovation projects can often be highly stressful, so the knowledge that you’re using a high-quality screeding product that will dry within hours of laying it can provide a welcomed relief of tension.
FastTrack Screeding can achieve a high-quality, smooth, level floor by using Ardex screeding products, and it’s ideal for minimising downtime and disruptions in your project.

UFHS installers are basically plumbers; they don’t typically know a great deal about floor screed. Most tend to suggest this because they believe liquid screeds wrap around the underside of the heating pipe, giving better heat transfer. But let’s face it, where is the heat going to go anyway? With a good amount of insulation, that should be under the heating pipes. It won’t be going through the insulation. Therefore, this is a misleading sales pitch used by UFHS companies which aren’t major suppliers and installers of floor screed. Take into account that thinner screeds, such as flowing screeds, can cause undesired hot/cool spots between heating pipes, so a lower thermal transfer would be an advantage.
Ardex only manufacture cementitious screed products, as they can then control the recipe, the raw materials and the polymers going into it, to ensure utmost quality.
Liquid products, on the other hand, totally rely on operatives on site to have the knowledge and facilities required to conduct the mixing process according to strict standards.
Ardex E100
Improves the elasticity and the compressive and tensile strengths of the modified mortar
Improves the workability and plastic properties of the mortar, but doesn’t increase the water content
Will reduce any early age crack formation and surface dusting of screeds, but will still increase their abrasion resistance
You can use with Ardex A38 ultra rapid drying cement for internal & external floor screeds, as a bonding slurry/grout