Suspended Floor (Under Joist) Insulation Solutions

INSULATING A SUSPENDED FLOOR FROM THE UNDERSIDE
Insulating a suspended floor from the underside is a common method of insulation, particularly for retrofit, refurbishment, conversion, and new build projects.
This method of installing suspended floor insulation allows you to make use of any crawl space available below the floor. Removing the need to take up carpets and floorboards, reducing the impact to the room above. Using our highly reflective, thin profile insulation offers great benefits, whilst achieving U-Values which will ensure you comply with Building Regulations and have a space which is comfortable for its occupants.
The recommended insulation for this method of construction is shown below.
SuperQuilt under joists

Our under joist insulation solution is great for projects where there is access the space below the joists.
Installing a layer of SuperQuilt pulled taut or recessed under the joists increases the overall thermal efficiency of the floor and makes use of the space below the joists.
Increase the overall thermal performance of the floor by simply increasing the depth of the joist cavity above the SuperQuilt.
Single or multiple layers of SuperQuilt can be used to achieve your desired U-Value, for more information speak to our technical support team on 01909 726 025
For projects where a lower U-value is required, why not try our Foiltec range.
150mm x 50mm Joists at 400mm Centres, with 150mm Cavity above & 350mm floor void below.
Description | P/A Ratio | U-Value |
---|---|---|
SuperQuilt (taut) | 0.1 | 0.09 |
SuperQuilt (taut) | 0.2 | 0.11 |
SuperQuilt (taut) | 0.3 | 0.12 |
SuperQuilt (taut) | 0.4 | 0.13 |
SuperQuilt (taut) | 0.5 | 0.14 |
SuperQuilt (taut) | 0.6 | 0.14 |
SuperQuilt (taut) | 0.7 | 0.14 |
SuperQuilt (taut) | 0.8 | 0.15 |
SuperQuilt (taut) | 0.9 | 0.15 |
SuperQuilt (taut) | 1.0 | 0.15 |
In accordance with ETA (CE Mark) Certification | (W/m²K) |
150mm x 50mm Joists at 600mm Centres, with 150mm Cavity above & 350mm floor void below.
Description | P/A Ratio | U-Value |
---|---|---|
SuperQuilt (taut) | 0.1 | 0.09 |
SuperQuilt (taut) | 0.2 | 0.11 |
SuperQuilt (taut) | 0.3 | 0.12 |
SuperQuilt (taut) | 0.4 | 0.13 |
SuperQuilt (taut) | 0.5 | 0.14 |
SuperQuilt (taut) | 0.6 | 0.14 |
SuperQuilt (taut) | 0.7 | 0.14 |
SuperQuilt (taut) | 0.8 | 0.14 |
SuperQuilt (taut) | 0.9 | 0.15 |
SuperQuilt (taut) | 1.0 | 0.15 |
In accordance with ETA (CE Mark) Certification | (W/m²K) |
Product Guides
Certification
YBS Insulation products are manufactured to the highest quality and our SuperQuilt is certified to industry standards.

YBS Insulation Product Information
Product - SuperQuilt - See more

SuperQuilt is one of the UK’s leading multifoil insulations. This flexible, easy to install, multilayer insulation offers tremendous thermal benefits. The benefit of multifoil insulation is that it is suitable for a range of applications from roof insulation, floor insulation and wall insulation and due to the slim depth, you can save valuable space on your installation. The unique composition of the product effectively deals with all forms of energy transfer.


This product is suitable for roofs, walls, floors and offers the following major benefits –
- Cost saving Solution
- Effective 2 in 1 insulation and vapour control membrane
- Reduces Construction Depth
- Reduces Risk of Condensation
- Non degradable maintaining thermal performance and product integrity
SuperQuilt has been independently tested and certified to the latest Industry Standards, including BDA Kiwa certificate of Agrément, Building Control Compliance (LABC registered detail) and NHBC Acceptance.

Product - Foil-Tec- See more

Foil-Tec is an ultra-thin, flexible, easy to install, vapour control membrane which effectively controls condensation and air tightness in both walls and roofs, while offering great thermal benefits. Foil-Tec can also be used independently as an insulation membrane in floor applications.

Foil-Tec is an ultra-thin, flexible, easy to install, vapour control membrane which effectively controls condensation and air tightness in both walls and roofs, while offering great thermal benefits. Foil-Tec can also be used independently as an insulation membrane in floor applications.
This product offers the following major benefits:
- Effective 2 in 1 insulating vapour control membrane
- Removes Risk of Condensation
- Non degradable, maintaining thermal performance and product integrity