Underfloor Heating & Anhydrite Screed Installation In Ilkeston

Location: Ilkeston, Derbyshire

Swipe

A property owner in Ilkeston required a complete underfloor heating and floor screeding solution for their 157m² property. Mitchell Plastering & Dry Lining Ltd was tasked with installing a full wet underfloor heating system with liquid anhydrite screed, providing an energy-efficient heating solution with a smooth, level floor finish. 

The project required careful coordination and expert installation to complete all work within a single visit, allowing the customer to return to the property the following day.

The Underfloor Heating Installation Process…

Polythene DPM Installation

The first stage involved laying a polythene damp proof membrane (DPM) across the entire floor area. This membrane provides essential protection against moisture rising through the floor structure, preventing damp problems that could damage the screed and compromise the underfloor heating system.

Polythene DPM comes in sheets that must be laid with overlaps at the joints. Our team positioned the membrane carefully, creating proper overlaps to provide continuous damp protection across the full floor area.

Tape Sealing The DPM

Once the polythene DPM was positioned, we fully tape sealed all joints and overlaps. This critical step creates a completely sealed moisture barrier, preventing any gaps where damp could penetrate through to the floor above.

Specialist DPM tape was applied along every joint, pressed firmly to create an airtight seal. The tape sealing extended to the perimeter edges where the DPM turned up the walls, providing complete moisture protection for the installation.

This meticulous sealing process takes time but provides long term protection. 

Installing 150mm PIR Insulation

With the DPM sealed, we installed 150mm PIR (Polyisocyanurate) insulation boards across the entire floor area. PIR insulation provides excellent thermal performance, preventing heat loss downwards through the floor structure.

The 150mm thickness specified for this project provides substantial insulation value, making sure the underfloor heating system operates efficiently. Without adequate insulation, much of the heat generated would be lost downwards rather than warming the room above.

PIR boards were laid tightly together across the floor, with joints staggered to prevent continuous lines of weakness. The boards were cut accurately around the room perimeter and any obstacles such as pipes or columns.

Wet Underfloor Heating Installation

With the insulation in place, our team began installing the wet underfloor heating system. This system uses pipes carrying heated water to warm the floor surface, providing comfortable, even heat distribution throughout the property.

The installation required careful planning to achieve optimal heat coverage across all 157m² of floor space. Our experienced installers positioned the pipes in continuous loops, spacing them according to the heat output requirements for each area.

10 Port Manifold System

The underfloor heating system was configured with a 10 port manifold. This manifold acts as the distribution centre for the heating system, with individual pipe loops connected to separate ports. This configuration allows different areas or zones to be controlled independently.

Pipe Installation & Layout

Underfloor heating pipes were laid across the insulation in carefully planned patterns. The pipes were secured using clips or rails that hold them at the correct spacing and prevent movement during screed installation.

System Pressurisation & Testing

Once all pipes were installed and connected to the manifold, the system was filled with water and pressurised. This crucial testing phase verifies that all connections are secure and the system is leak free before the screed is laid.

The system was pressurised to test pressure and monitored for any pressure drop that would indicate a leak. 

Our team carefully inspected all connections, pipe runs, and the manifold to verify integrity throughout the system.

This testing must be completed successfully before screeding can proceed. Any leaks discovered at this stage can be rectified easily, whereas a leak discovered after screeding would require excavation to repair.

For this Ilkeston project, the underfloor heating system passed pressure testing without issues, confirming the installation quality and allowing us to proceed with confidence to the screeding stage.

Liquid Anhydrite Screed Application

The final stage involved laying liquid anhydrite screed over the underfloor heating system. Anhydrite screed is a calcium sulphate-based material that flows smoothly to create a perfectly level surface whilst encasing the heating pipes.

Liquid screed offers significant advantages for underfloor heating installations. Its fluid consistency allows it to flow around the heating pipes, creating excellent thermal contact and heat transfer. The self-levelling properties provide a flat surface with minimal manual work.

50-60mm Screed Depth

We applied the liquid anhydrite screed to a depth of 50-60mm across the entire 157m² floor area. This depth provides adequate coverage over the heating pipes whilst creating a durable floor surface that can withstand normal foot traffic and furniture loads.

The liquid screed was pumped into the property and poured systematically across the floor. Its flowing nature allowed it to spread evenly, finding its own level and filling around the heating pipes completely.

Our team used specialist tools to guide the screed and achieve consistent depth across the floor. The self-levelling properties reduced the manual finishing work required compared to traditional sand and cement screeds.

Single Visit Completion

The entire installation, covering 157m² and including DPM, insulation, underfloor heating, and liquid anhydrite screed, was completed within a single site visit. This efficient project management and execution minimised disruption for the customer.

Our experienced teams worked systematically through each stage, with materials and equipment organised to maintain steady progress throughout the day. The careful planning ensured no delays or complications interrupted the workflow.

By completing all work in one visit, the customer could return to their property the following day once the screed had set sufficiently. This rapid turnaround demonstrates our commitment to efficient service delivery whilst maintaining quality standards.