UNDERFLOOR HEATING SCREEDS OVERVIEW

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.

FREQUENTLY ASKED QUESTIONS ABOUT UNDERFLOOR HEATING SCREEDING

Are Ardex screeds are completely compatible with underfloor heating

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.

For advice on the best choice of screed for your floor, to enable your underfloor heating to be turned on at the soonest possible, get in touch with Fast Track Screeding.

What type of floor screeding should I have in my new house/extension

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

Ardex A23 produces quick drying floor screeds. The product is so quick to dry that you will be able to walk on it and continue work only 5 hours after it is laid it’s an impressive product when traditional screeds taking a number of months to dry.

What type of floor screed drys in 24 hours?
Ardex A35

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

Ardex A35 is an ultra-rapid drying floor screed which can be walked on 3 hours after laying it down, regardless of thickness. Your choice of floor covering can then be installed and your floor will be ready within just hours of starting work. Now if that’s not efficient, then I don’t know what is!

What type of floor screed is suitable for wet rooms and external areas?

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

While traditional screeds can take months to dry, Ardex A38 is a polymer-modified cement screed that can receive tiles after only 4 hours. It’s ideal for swimming pools and shower rooms and can be ready to receive vinyl and wood floor coverings after just 48 hours.

When can I turn on the Underfloor Heating?

Clients often find after having there Underfloor Heating System fitted, they can’t turn it on until the screed is fully dry.

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.

When using the ARDEX Screed System, you can turn on your Underfloor Heating in as little as 3 days.

How long does Screed take to dry?

With regard to drying times, the British standards (BS 8204) state that a Standard Traditional Screed will take 1mm per day, up to 50mm, and considerably more over that thickness to dry out, and that would be in ideal summer conditions of 18c to 20c.

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.

If you have any questions about Fast Drying Screeds or any of the Ardex screeds we have available, please don’t hesitate to get in touch.

When can I walk on the Screed?

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.

When using the ARDEX Screed Systems, you can walk on the screed in as little as 3 hours and no curing polythene is required.

How soon can I lay my floor Coverings?

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.

With using the Advanced and Ultimate Screed systems, you can lay floor coverings in as little 4 hours regardless of the thickness of the Screed.

Why should I use Ardex products?

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.

Your screed could be walked on within hours, so there is no time wasted and you can soon begin laying your choice of flooring.

My under-floor heating system installer has told me that self-levelling ‘flowing’ screed is the best for UFHS, why is this?

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.

By providing cementitious Ardex Screed products we eliminate this risk of error, ensure quality control and facilitate a high-quality finished result.

How can you reduce any early age crack formation and surface dusting of screeds?

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

Whether you’re using screed and rendering mortars for internal or external locations, use Ardex E100 to improve tensile and compressive strengths along with increasing elasticity and bond strength of the modified mortar. Ardex E100 is an acrylic-based additive and available to order directly from our online store.

UNDERFLOOR HEATING SYSTEMS

 

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.

BENEFITS OF UNDERFLOOR HEATING SCREEDS

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.

If you have any questions about our Installation Service or any of the Ardex screeds we have available, please don't hesitate to get in touch.