Solid Floor Systems

solid underfloor heating build up by Giacomini


Solid floor systems include all floor constructions that have underfloor heating pipework embedded in concrete or screed. These floors will be laid onto a sub-base, which can be a concrete base or a block and beam sub floor.

Benefits Solid

Solid Floor Systems diffuse the heat across the screed surface, providing an even temperature at floor level.




+ Economic solution

+ Simple to install

+ Versatile to construction requirements (depth, insulation, and screed)

+ For use with a wide range of floor coverings

+ Flexible design with multi-directional pipework

+ High heat output (maximum 100 W/m2*)

+ Once at temperature the structure's mass retains heat for longer

* Dependant on floor finishes & desired ambient temperatures

Click here to view project case studies

System Types

Tacker System

Giacomini’s most frequently installed system, the tacker solid underfloor system offers a cost effective solution with great versatility.  Fast and easy to install the tacker clips, with push fit barbs, offer a hassle free and secure fixing mechanism for pipe.

The floor construction typically consists of the sub-base, which is made up of two layers, the first being a compact or consolidated hard-core, which will have a sand blinding layer on top. Next a 1200 Gauge damp proof membrane (DPM) is laid, onto which the concrete slab oversite would be poured or a beam and block floor built. Certain locations may require a thicker 2000 Gauge polythene to provide a radon gas barrier. 

Edge insulation is installed to the perimeter of the building and a layer of rigid insulation is positioned. This is necessary to meet current building ‘U’ values and to comply with current building regulations, as well as to reduce downward heat loss. On top sits the vapour barrier, which is taped together at the seams. 

Giacomini pipework is then laid according to the system design and held in place with poly-propylene U-Clips, installed using a Tacker gun

Finally the screed is poured to the specifications agreed within the design criteria.

This style of solid system typically requires a minimum floor build-up of 75mm (depending on insulation requirements).


Clip Rail System

Clip rail systems provide a fast and exact method for fixing underfloor heating pipework. With self-adhesive and/or screw points the system can be installed over rigid insulation, or solid concrete and beam & block subfloors when the insulation is too thin for staples. The clip mechanism provides a secure hold for the pipe, whilst neatly supporting pipe bends to ensure even spacing.

The ready-made pipe spacing means clip rail systems are especially suitable for large square or rectangular spaces. 


Castellated Grid System (Low-Profile)

Giacomini’s low-profile ‘Spider’ grid systems have been designed for new build and renovation projects, where floor depth is limited due to room height restrictions. Made with recycled high-resistance PPR, the products’ patented geometry uses a three-dimensional open lattice castellated panel to hold the pipe firmly in place.

The interlocking panels can easily be installed over existing subfloors* to form a continuous layer in which the pipework is neatly laid according to the system design. The panels’ design ensures that the pipework is completely embedded in the screed for even temperature distribution with a low degree of thermal inertia. 

The Spider Slim system with 12 mm polybutylene pipework can achieve a total system height of as low as 20mm (including screed).

The Spider system with 16-18 mm polybutylene pipework can achieve a total system height of as low as 25mm (including screed).

Across the Spider ranges there are three panel configurations available: Self-adhesive, with insulation pins and with high-density insulation. Please note, system height varies depending on the option selected.

* Edge insulation and a sealed vapour barrier must be in place before commencing.

Gypsum-Fibre Overlay System (Low-Profile)

Low-profile overlay system ideal for retrofit applications. Using strong and durable gypsum-fibre panels the system can easily be installed over existing subfloors. 

Each panel is 18mm in thickness, which neatly houses the 12mm polybutylene pipework. Three panel designs are available including sections for delivery and return pipework and manifold connections. Each panel measures 1200 x 600 mm and weighs around 15kg (21kg/m2), making it suitable for one person lifts.

The dense gypsum-fibre construction contains no plastic supports, allowing a high heat output from 100% of its surface. 

The system’s panel assembly makes it quick to install, reducing disruption and time on site. It is compatible with a wide variety of floor coverings, including carpets, tiles, wooden and laminate flooring. For most floor coverings a thin 5mm separating layer of floor leveller (fluid screed) is required.


Structural Floor Systems

Typically incorporated into load-bearing floors or large area applications (e.g. schools, sports/leisure complexes, factories and warehouses) with sand cement screeds, structural floor systems are installed on top of a reinforcing wire mesh grid. This improves the screed’s flexural strength allowing it to accommodate expansion and contraction stresses. The structure also reduces the risk of shrinkage cracking around the pipework. 

The installation of structural floor systems is similar to traditional screed systems, with the concrete floor slab laid over the underfloor pipework. The main system difference is how the pipework is fixed prior to screeding, with cable ties used to secure the pipework to the wire mesh. It is important to be aware that this is a more time and labour intensive process.

Large area applications may require floor expansion or movement joints. Though not always avoidable, pipework crossing these joints should be kept to a minimum. Where crossing does occur protection using a pipe sleeve is required to accommodate for movement within the heated screed or concrete floors.


UFH Quotation

Submit your plans

Contact our underfloor heating design team for a detailed estimate.

Our in-house design team will carefully review your mechanical and/or architectural specifications to help you find the perfect heating solution for your application. 

Click here to submit your plans.

E-Learning Academy

E-Learning Academy​

Our E-Learning Academy provides online access to a variety of product seminars, free to complete from your own PC, in your own time. 

Alternatively, we’re happy to come to your offices for group CPD sessions, with lunch on us!

Click here to access our online presentations.



“We continually receive great service from Giacomini together with products and systems which often exceed customer specifications. Furthermore, we received fantastic support in relation to the bespoke tacker fit system installed at UK Hydrographic Office (UKHO), which recently won ‘Commercial Project’ at the RICS Awards, South West.”