water underfloor heating system

Water-based underfloor heating systems are an excellent solution for those looking to provide comfort in either new buildings or older ones. This type of heating system uses warm water that flows through a network of pipes embedded in the floor, evenly heating the room from the bottom up. The heat distribution in water-based underfloor heating systems is consistently the same across the entire floor surface

Water-Based Underfloor Heating Systems for New Buildings

Nowadays, many people with new buildings prefer heat pumps as their energy source. Heat pumps are highly efficient when we use water-based underfloor heating systems. The ideal low temperature for a heat pump to operate is between 30–45°C, which is also perfect for underfloor heating. Although it heats up more slowly, the water-based underfloor heating system retains heat longer.

The following is an overview of the steps for starting installation in a new building:

Installation Preparation

This wet system underfloor heating is an ideal choice for new buildings. In new builds, wet UFH integrates easily with the screed stage, whereas electric mats can be simpler for small retrofits. Installers only need to embed the pipes for the warm water lines into the screed after laying insulation and pressure-testing the circuits before the floor is finished. The thermostat is then set in each room, providing both comfort and improved energy efficiency.
Meanwhile, the choice of flooring types, such as tiles and engineered wood, can enhance heat transfer.

Insulation

This wet system follows the principle of neat installation, with screed usage in tile areas where pipe installations are underneath. Typically, this is good in the kitchen, living room, and bathroom. For wooden floors in the bedroom and living room, it’s important to ensure proper insulation. The wood must also be suitable, such as engineered oak typically ≤18 mm is recommended (check supplier data). Then, insulation is crucial for reducing heat loss downwards. Installers usually use high-quality floor insulation boards beneath the pipes and provide insulation for all residential areas, including both the ground floor and upper floors.

Control System

Water-based underfloor heating systems use a smart zoning method, with thermostats installation in each room or zone. This allows users to control the temperature in different rooms independently. Additionally, this control system can integrate with home automation systems for greater convenience.

Estimated Cost

Water-based underfloor heating systems for renovations usually cost between £45–£75 per m². Installation is relatively quick and straightforward, with labor costs ranging from £30–£50 per m². Additionally, it’s recommended to pair with a room thermostat for better control and efficiency. A smart thermostat for the whole house typically costs between £300–£600. Based on our observations, these figures reflect common UK market ranges; however, actual prices can vary depending on region, installer, and project specifications.

Water-Based Underfloor Heating Systems for Building Renovations

Implementing water-based underfloor heating systems in renovation projects requires careful planning. It’s important to consider the condition of the existing floor and the available room height.

Here are some key considerations when preparing water-based underfloor heating systems for building renovations:

Floor Surface

Traditional wet heating systems typically require screed and insulation, which means often 50–100 mm total build-up (insulation plus screed) may be required. Unfortunately, this added height can interfere with doors and skirting boards. As an alternative, you can consider a thinner surface build-up of 15–22 mm. In this case, there’s no need for a full screed. Instead, you can use grooved or foil-faced boards design for underfloor heating. These boards can be lay directly over the existing floor. The final floor surface can be engineered wood, tiles, or vinyl. Then, simply connect the system to the existing heat pump or boiler. This setup is ideal for kitchens, bathrooms, and extensions undergoing renovation.

Board Selection

In some cases, accessing upper floors or finished areas for reinstallation can be challenging. Additionally, screed drying times can delay the project by several weeks—even when fast-drying screeds are in use. A practical solution for renovation projects is to use high-performance EPS boards with pre-formed pipe channels. These systems typically have a build-up of around 16–18 mm. Installation is quick, and these systems warm up faster than traditional screed UFH. Once installation, you can lay tiles or position wood/vinyl flooring directly over the boards.

Estimated Cost

Water-based underfloor heating systems for renovations usually cost between £45–£75 per m². Installation is relatively quick and straightforward, with labor costs ranging from £30–£50 per m². Additionally, it’s recommended to pair with a room thermostat for better control and efficiency. A smart thermostat for the whole house typically costs between £300–£600. Based on our observations, these figures reflect common UK market ranges; however, actual prices can vary depending on region, installer, and project specifications.

Main and Additional Components

When installing water-based underfloor heating systems, it’s important to consider both the main and additional components.

The main components include:

Plastic Pipes

These durable pipes are essential for carrying warm water throughout the system.

Manifold

The manifold distributes water evenly to each circuit and controls the temperature in each zone.

Insulation

Place it beneath the pipes, insulation helps prevent heat loss downwards, ensuring the system operates efficiently.

Floor Screed or Concrete Layer

This layer encases the pipes, helping to distribute heat evenly throughout the floor.

Additional components may include:

Thermostats and Control Panels

Room or zone thermostats, wiring centres, or smart control panels that let you set and monitor temperatures independently.

Edge Insulation Strips

Placed around the perimeter of rooms to prevent heat loss into walls and allow screed expansion.

Manifold Pump & Mixing Unit

If the heat source runs hotter than UFH requires, a pump and blending valve may be fitted at the underfloor heating manifold to lower the flow temperature.

Expansion Joints & Fixings

Clips, rails, or staples for securing pipes and any necessary joints to accommodate screed movement.

Final Note

These components work in conjunction with heat sources such as biomass boilers or renewable energy sources like air-source heat pumps, to provide an efficient and sustainable heating solution.