Renovation projects using Slimline UFH solutions

Problematic substrates are ubiquitous on refurbishment projects, leading to problematic ceramic floor tile installation.

Unfortunately, in the case of renovation work, these critical substrates may only come to light when the walls or floors are uncovered, complicating and delaying the design process.

Critical problematic substrates are not confined to renovations, of course, with similar problems arising on many new-build projects. Such problems are particularly likely to occur where substrates have been damaged during site operations, incorrectly installed or due to contractual time pressure, exhibit high levels of residual moisture.

The flooring experts at SMET have an unprecedented wealth of technical expertise in troubleshooting and delivering solution focused repair and retrofit of any problematic renovations.

Retrofitting Slimline Under Floor Heating Solutions

Underfloor heating (UFH) systems have been an established solution on residential and commercial projects for many years now. They are described in British Standards in BS 8204 parts 1 and 7 and in German standard DIN 18 560 Part 2 – ‘Floor screeds and heated floor screeds on insulation layers’.

The constructions described in the BS and DIN standard are often difficult to implement due to the required layer thicknesses, which particularly on refurbishment schemes, may not be available.

SMET has the perfect solution to the demand for the retrofitting of UFH in renovations.

With a total construction height of approximately 17 – 20 mm, new slimline heating assemblies can be installed as total system solutions on existing floors using standard Sopro tile-fixing products such as separating layers, floor levelling compounds and thin bed adhesives, in combination with slimline UFH solutions such as Kermi.


The most straightforward solution can be adopted where the system is to be installed on a strong existing covering (tile, natural stone), an existing screed or concrete floor.

The Kermi heating system is directly bonded to the substrate after this has been cleaned and pretreated with Sopro GD 749 primer or Sopro HPS 673 bonding primer. The honeycomb structure with heating pipes is levelled with Sopro FS 15 550 floor-levelling compound or Sopro FAS 551 fibre reinforced self-levelling compound, with minimum cover for the system of 3mm, or Sopro SLC 578 with a minimum cover of 8mm.


Slimline hot water floor heating systems are also suitable for installation on timber and other critical substrates (composite substrates, surfaces with hairline cracking etc) that may be encountered on refurbishment projects.

Such substrates are stabilised and separated from the heating assembly through the incorporation of (a minimum of 4mm) Sopro FDP 558 tile insulation board. The timber substrate must first be secured as directed and pre-treated with Sopro HPS 673 bonding primer, levelled where necessary with Sopro FAS 551 fibre-reinforced self-levelling compound and covered with adhesive fixed (min. 4 mm) Sopro FDP 558 tile insulation board.

The insulation board is bonded using a rapid-set tile adhesive (Sopro’s No.1 rapid-set, Sopro FKM 600 etc). The subsequent procedure is the same as described under ‘Installation on solid substrate’.

As total construction height of the heated layer runs to only around 17mm, it’s an ideal total solution for refurbishment applications.

Smet Building Products Ltd stocks a comprehensive range of superior, German-made materials and with a superior technical know-how, the team will help you renovate any critical surface. Get in touch with the experts at SMET to discuss your renovation project.

SMET wins Best Small Business Award 2017_presented by Translink

SMET wins Best Small Business Award 2017_presented by Translink

Smet Building Products Ltd (SMET) is dedicated to delivering innovative Self Levelling Floor ScreedsRendersPlastersProfessional Tiling Systems, AdhesivesLime products,  and Streetscape® BS 7533 Compliant Mortars.

As a family run business, our strength is in delivering innovative high-quality products supported by exceptional technical and conscientious customer service. We will take the time to advise and support you, offering onsite logistics and sound expertise. With our products and our support, you’ll soon find improved site management, time-saving, quality improvements and waste reduction.  Our quick growing success can be attributed to our unmatched wealth of expert knowledge and experience in providing technical advice, problem-solving back up, responsive support and solution focused service.SMET will meet the complex demands of architects, specifiers, designers and end-users – for all phases of construction.