The choice of underfloor heating system is only part of the specification process for underfloor heating. When installed with a screed floor, the equally important decision is the depth of screed applied as this directly impacts the thermal performance, energy efficiency and running costs of the UFH system.
Clockwork Underfloor Heating specialises in the installation of underfloor heating systems with screed floors. Working in collaboration with our sister company Clockwork Screed, we provide a seamless service with just one point of contact.
A central question we quickly address on each project is, how thick should the screed be over the underfloor heating pipes? Before we answer that here, let’s explore what screed underfloor heating is.
Screed underfloor heating
Screed underfloor heating is the installation of an underfloor heating system under a screed floor. The UFH system can be either dry (electric) or wet, which consists of pipework heated from a boiler or renewable heat source.
The cementitious liquid screed we supply is strong and durable with exceptional thermal conductivity. It is also self-levelling, and self-compacts so the liquid naturally covers all the pipework to prevent gaps from developing which would allow heat to escape down into the subfloor. All of these benefits optimise the performance of the UFH system, making liquid screed the ideal choice for underfloor heating systems.
Screed depth and underfloor heating
So, back to our original question. How thick should screed be over underfloor heating pipes?
For wet underfloor heating systems, the required depth is between 40mm and 75mm, depending on the type of screed used. This includes the diameter of the pipes. For all screed types, around 20 to 30mm of the screed needs to be above the pipes.
On dry underfloor heating systems, significantly less screed is required. The minimum depth is 10mm above the cables, although an additional 5 to 10mm improves the heat distribution and reduces the risk of damage during installation.
Screed thickness requirements by screed type
When using traditional sand and cement screed for wet UFH installations, the screed depth should be between 65 and 75mm, including the diameter of the pipes, to optimise the performance of the UFH system.
The enhanced thermal conductivity of liquid screeds, such as the cementitious liquid screed supplied by Clockwork Underfloor Heating, compared to traditional screeds, means they can be laid more thinly at a depth of between 40 to 50mm, with 20mm above the pipes.
Factors to consider when selecting screed thickness for UFH
When installed in commercial or industrial buildings, the depth of a screed floor with underfloor heating may need to be increased to accommodate higher loading requirements such as heavy machinery and higher footfall. This can require 100mm or more of screed above the pipes.
The thicknesses outlined above are based on a standard pipe diameter (16mm) and standard spacing (150 – 200mm). Larger diameter pipes (20mm) and narrower or wider spacing may require different screed depths to maintain consistency in heat distribution across the floor surface.
Speak to UFH experts to ensure the correct thickness of screed for underfloor heating
Clockwork Underfloor Heating will ensure your UFH screed is specified correctly. Contact us to discuss your project.
Plan, Insulate, Heat and Screed
Our 4 Step Process
1
Planning & design
2
Lay insulation
3
Install underfloor heating
4
Pour liquid floor screed
PROJECT FOCUS
High end Residential, Manchester
We planned and installed an underfloor heating system into a contemporary home in Manchester. Not only that, we finished the installation with a smooth, even and high quality liquid floor screed.
Our team worked with the end user’s architect, ensuring the home benefitted with a visually striking but also inherently comfortable and environmentally conscious heating solution.
The client now enjoys an enhanced living experience, reduced energy bills, and an aesthetically uncompromised living space that flows through the whole house.
See What Our
Customers Say
“From our initial consultations to the flawless installation, Clockwork’s team demonstrated not just technical prowess, but a nuanced understanding of architectural essentials.
Their underfloor heating system effortlessly merged into our designs, preserving every ounce of spatial aesthetics while embedding an unperceivable, yet palpably comforting warmth throughout the residence.
In Clockwork, I found more than a solution provider; I discovered collaborators who understand, respect, and enhance the architectural journey. Their integrative approach, precision, and unyielding commitment to quality have made them my go-to partners for all underfloor heating needs.”
D. Smith
Architect, Cheshire
Why work with us
For your Underfloor Heating Project?
Expertise in underfloor heating: Specialists in underfloor heating installation for residential and commercial needs.
Unique advantages: Providing distinct benefits over traditional heating methods to both homeowners and businesses.
One-stop solution: Offering a comprehensive four-step process (Plan, Insulate, Heat, & Screed) for a streamlined underfloor heating solution.
Collaborative approach: In partnership with our sister company, Clockwork Screed, ensuring a unified solution for insulation, underfloor heating, and screeding.
Simplified project management: Eliminating the complexity of dealing with multiple suppliers, facilitating a smoother and hassle-free project execution for architects, contractors, and homeowners.
