How to achieve 0.18 U-value – Solid Floors

If you are currently insulating a concrete floor to building regulations standard, you may be requested to achieve a U-value of 0.18. Achieving a U-value of 0.18 for floors is very common for domestic and non-domestic floor applications.

A usual method of hitting this low U-value, would consist of a thick amount of Rigid PIR Insulaiton. Using a thick amount of PIR can be costly and could loose precious head-height.

Understanding U-values

A U-value is a measurement of heat loss, and can explain the energy efficiency of an area, e.g. Roof, Wall, Floor, Windows. The lower the U-value, the less heat will escape from that area. If you are renovating a concrete floor, or building an extension, it is essential to ensure the floor is achieving the respected U-values.

A U-value is calculated by a sum of all the thermal resistances layers that makes up the structure. For example, in a roof, you would generally find tiles, membranes, airgaps & timber, so all these factors can impact the U-value in either a positive or negative way.

SuperQuilt for Solid Floors

How to achieve 0.18 in Floors using SuperQuilt

U-value building regulations in 2024

Current target U-values were set in June 2022, these can be view in the table below. You can find our more information on Part L on the following link, from the UK government website – See Data Source.

U-value requirements for existing dwellings – 2022 onwards

Application Current U-value
Roof (Pitched & Flat Roof) 0.15
Wall 0.18
Floor 0.18

Recommended Product

Multifoils Direct’s recommend product for insulating solid and concrete floors is YBS SuperQuilt. SuperQuilt is a 40mm multifoil, compressing to 7mm at it’s thinnest point. Aswell as floors, SuperQuilt is certified for roofs and walls. It’s 19 layers consists of true aluminium foils, recycled waddings and PE foams.

How to achieve 0.18 U-value - Solid Floors

How to achieve 0.18 U-value – Solid Floors

Below are some of the key benefits of YBS SuperQuilt;

  • Equates to up to 100mm Rigid Insulation in Floors
  • Fully agremont certified by BDA
  • UK Manufactured
  • Itch and floating fibre free
  • Class E surface spread of flame
  • Made from 83% recycled materials

Installation method for 0.18 U-value

Below is our recommended build-up to achieve a 0.18 U-value;

  • Solid Concrete Floor
  • 1st Layer SuperQuilt laid flat on floor
  • 50mm Battens with narrow centres
  • 2nd Layer SuperQuilt stapled taut over battens
  • 22mm Chipboard Finish
  • U-value achieved = 0.18 or lower

This detail will take up a total depth of approx 86mm.

Require approval from Building Control?

If your project is going through building control, it is likely they will want to see documentation. We can help with this! If so, please use our Request a U-value form. Please mention your floor build-up, alongside m2 coverage. We will then email a bespoke calculation and quote within 24 hours. (Monday – Friday)

Delivery Schedule

Multifoils Direct offers YBS SuperQuilt with next-working day delivery!

You can purchase these as loose rolls, or save cost with our Trade Pallet Deals!

See below links to order both online with next-working day delivery;

SuperQuilt Loose Rolls – Click Here!
SuperQuilt Trade Pallet – Click Here!


All build-ups and suggestions are provided in good faith. We recommend having these details double checked by building control before proceeding. The U-value table is a guide, and your desired target U-value is to be advised from your building inspector. Please check the calculations for correct air-gaps and battens, battens may be required to be installed perpendicular to how they are supplied in the image. 2D images are not to scale, and for illustrational purposes only. Multifoils-Direct cannot be held responsible for any losses financially or physically from advice provided on this webpage