Water Underfloor Heating Kits | Complete UFH Kits

Screed vs Joist vs Overlay- Which to Choose?

Choosing the right water underfloor heating system depends on your floor construction, available build-up height, and whether the project is a new build or renovation. The three main system types are in-screed, joist, and overlay, each suited to different applications.

In-Screed Systems

In-screed underfloor heating is installed within a new floor build-up, where the pipe is embedded into a sand and cement or liquid screed layer. This is the most common option for new builds and extensions.

Best suited to new floors or full floor replacements
Pipe fully embedded in screed for even heat distribution
High thermal mass provides stable, consistent heating
Requires sufficient floor build-up height

This system is typically chosen where maximum performance and long-term efficiency are the priority, and floor height is not restricted.

Joist Systems

Joist underfloor heating is designed for suspended timber floors, where pipe is installed between joists using aluminium spreader plates. It is commonly used in upper floors or timber ground floors.

Designed for timber joisted floor constructions
No need to raise floor height significantly
Aluminium plates help distribute heat across the floor
Suitable for retrofit or renovation projects

This system is typically selected when working with existing timber floors where installing a screed is not practical.

Overlay Systems

Overlay underfloor heating systems are installed on top of existing floors using pre-routed insulation boards. These systems are designed for projects where minimal disruption and low floor build-up are required.

Installed directly over existing concrete or timber subfloors
Low profile solution with minimal height increase
Pre-routed boards ensure consistent pipe spacing
Faster installation compared to screed systems

This system is commonly used in retrofit projects where removing the existing floor is not feasible.

Which System Should You Choose?

If you are installing a new floor and can accommodate screed depth choose in-screed
If you have a suspended timber floor with 400 centre joists, choose joist kits
If you need a low build-up system over an existing floor, choose overlay

All three systems provide even heat distribution and can be designed for either single room or multi-room installations. The correct choice depends on the structure of the property, available floor height, and the type of project being carried out.

Find the Right Underfloor Heating Kit

Use this guide to choose the correct underfloor heating kit based on your floor construction, heat requirement, and whether you are heating one room or multiple rooms.

Step 1: What type of floor do you have?

In-Screed Kits

Choose this option if you are installing a new floor build-up and the pipe will be embedded within screed.

View In-Screed Kits

Joist Kits

Choose this option if you have a suspended timber floor and the UFH pipe will be installed between the joists.

View Joist Kits

Overlay Kits

Choose this option if you need a low build-up system installed over an existing concrete or timber subfloor.

View Overlay Kits

Step 2: Do you need high output or standard output?

High Output Kits

150mm pipe centres
Best for rooms with higher heat demand, lower water temperature systems, and air source heat pump (ASHP) installations.

Standard Output Kits

200mm pipe centres
Best for well-insulated properties with lower heat demand, commonly used with modern boiler systems.

Step 3: Are you heating one room or multiple rooms?

Single Room Kits

Designed for one room or one heating zone. Controlled by a single thermostat.

Multi Room Kits

Designed for multiple rooms or zones. These kits include a wiring centre and thermal actuators, allowing each room to be controlled separately with the addition of a thermostat in each room.

Quick Selector

Choose In-Screed if you are creating a new floor and can install the pipe within screed.
Choose Joist if you have a suspended timber floor and need to install between joists.
Choose Overlay if you are renovating and need a low build-up system over an existing floor.
Choose High Output if you need greater heat output or are using a heat pump.
Choose Standard Output if the area is well insulated and heat demand is lower.
Choose Single Room for one area controlled by one thermostat.
Choose Multi Room if you want separate room-by-room control.

Shop by Kit Type

Screed Kits

Single Room Screed Kits

Multi Room Screed Kits

Joist Kits

Single Room Joist Kits

Multi Room Joist Kits

Overlay Kits

Single Room Overlay Kits

Multi Room Overlay Kits