Research from RICS shows growing demand for energy efficient commercial building spaces across Europe. Ensuring a good level of fabric performance across the envelope should be a key consideration for property developers looking to meet this demand – this includes ensuring the large commercial floor spaces are well insulated. By addressing these areas properly during the initial build, it should help to make the spaces attractive for tenants now and future-proof them against potential future requirements for them to be net zero operational carbon.
In this article, we’ll look at some of the key considerations when insulating a commercial floor including:
- What insulation material is best for commercial floors.
- What U-values you need to achieve.
- Best practice tips for achieving an accurate installation.
What insulation is best for commercial floors?
There are a number of different commercial floor insulation materials available. The right choice for your project will depend on a few factors including:
- target U-value;
- available budget; and the
- end-use for the space (whether it will need to handle heavy machinery)
Phenolic floor insulation
Phenolic insulation boards such as our Kooltherm K103 Floorboard can achieve some of the lowest thermal conductivities of commonly used insulation products. This makes them well suited to commercial applications where an ambitious U-value is targeted as it may be possible to achieve these with a slimmer overall thickness.
PIR floor insulation
PIR Insulation such as Thermafloor TF70 generally have a somewhat higher thermal conductivity than phenolic insulation. Both phenolic and PIR boards are suitable for standard foot traffic.
XPS floor insulation
In cases where the floor needs to handle heavy weights such as machinery or vehicles, a heavy duty floor insulation will be needed. Extruded Polystyrene (XPS), such as Kingspan GreenGuard, typically have a high compressive strength, making them suitable for these applications.
Our Kingspan GreenGuard range is available in grades up to 700 kPa covering all typical heavy-duty applications. At the same time, XPS boards have higher thermal conductivities that for phenolic or PIR boards. In the case of Kingspan GreenGuard, these start at 0.033 W/mK. This means that a greater thickness will typically need to be installed compared with phenolic or PIR boards.
What U-values do commercial floors need to achieve?
In all cases, commercial floors need to be insulated to the levels set out in Part L of the Building Regulations in England and Wales or Section 6 (Energy) of the Building Standards in Scotland.
In each case, these set clear limiting U-values. These are the worst possible U-values that can be achieved as an area weighted average for the total floor area. In most cases, to reach compliance, project teams will look to achieve floor U-values which improve on these values.
The U-values contained in the Notional Building Specification can act as a starting point. This specification is used in energy calculation software using a theoretical building of the same dimensions as the actual project. From this, the software generates the performance targets that the actual building is compared against. Whilst not compulsory, the Notional Building specification Uvalues often form a starting point for the actual specification.
Both the limiting and Notional Building U-values are shown in the table below
| Area weighted U-values (W/m2K) | |
Area | Notional Building | Limiting U-value |
Part L 2021 – England | 0.15 side-lit activities | 0.18 |
Part L 2022 - Wales | 0.22 | 0.22 |
Section 6 (Energy) 2022 - Scotland | 0.13 | 0.18 |
Learn more about the energy targets in the Building Regulations and Standards
Can I just insulate the floor perimeter?
The floor edges are usually responsible for the majority of heat losses. For commercial buildings with very large ground floor areas, this may mean it is unnecessary to insulate the entire floor area and that the desired U-value can be achieved by just insulating the perimeter of the floor. If adopting this approach, you will still need to ensure that the average area weighted U-value meets or improves on the limiting U-values outlined above.
Top tips for choosing and installing commercial floor insulation
When installing rigid insulation boards, there are a few best practice points that should be considered along with the standard manufacturer instructions.
Where the boards are laid, whether this is across the entire floor space or at the perimeter, they should be butted with no gaps. Where boards are overlayed, the joints should also be offset. A separation layer will also typically need to be fitted above the insulation to protect it from the concrete or screed.
To prevent thermal bridges around the perimeter of the floor, a strip of the insulation board (typically at least 25 mm thick) should be placed vertically around the perimeter of the floor slab to prevent cold bridging. The wall insulation should also reach at least 150 mm below the top surface of the floor insulation or upstand insulation when insulating the whole floor, or 225 mm below when insulating just the perimeter.
Specific best practice guidance on handling and installing our floor insulation boards is available in the Sitework section of the product literature.
On site training and support
Build your team’s knowledge with onsite training and support from one of our Product Technicians. The presentations cover the full range of Kingspan products and applications from flooring to roofing and everything in-between with both internal and external wall insulations.
