How to achieve 0.15 U-value – Pitched Roofs
How to achieve 0.15 U-value – Pitched Roofs – We understand that achieving U-values for building control can be difficult. Especially when you are up against head-height restraints, alongside constant rising costs on materials.
What is a U-value?
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 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 and timber. All these factors can impact the U-value in either a positive or negative way.
The lower the U-value, the less heat will escape from that area. If you are renovating, or building a dwelling, it is essential to ensure the building is achieving the respected U-values. In addition, due to rising energy costs, lower U-values will result in lower energy bills.
Building Regulations for U-values in 2023
Approved Document Part L has been updated in relation to U-values, heat gain and heat loss. The new rules came into play in June 2022. More information on Part L can be found at the following link on the UK government website – See Data Source.
New for 2023 – U-value requirements for existing dwellings
Roof (Pitched & Flat Roof)
What does this mean for my project?
In a nutshell, the lower the U-value requirement, the more insulation is required for your project.
Multifoils Direct are the leading distributor of both SuperQuilt and BreatherQuilt. Both these product are multi-layered blankets consisting of reflective foils, PE foams and recycled waddings. These products are proven space-savers, due to their slim profiles alongside excellent R-value ratings. In the recommended systems below, you will find details including SuperQuilt and BreatherQuilt, also SuperQuilt with additional insulation materials.
SuperQuilt For Pitched Roofs
- SuperQuilt – Product Link – Click Here!
- 40mm multifoil with 19 layers
- Compressed to just 7mm
- BDA & BBA Agremont Certified
- Built-in Vapour Control Layer
- UK Manufactured
- Made of 83% Recycled Materials
BreatherQuilt For Pitched Roofs
- BreatherQuilt – Product Link – Click Here!
- 11 Layer Multifoil
- 40mm thickness, 7mm compressed
- BDA Agremont Certified
- 3-in-1, Waterproof, Breathable and Insulating
- UK Manufactured
- Made of 72% Recycled Materials
Systems to achieve 0.15
Multifoils Direct have a variety of methods and systems to achieve current U-value regulations, for pitched roof projects. The details below vary, depending on if you are insulating under the rafter, over the rafter, or a combination of both. You will also find the minimum rafter depth required for the project in the comments under each image.
Option A – 3 Layers SuperQuilt, Standard Plasterboard – Insulating Under Rafter
Option B – 2 Layers SuperQuilt, 52.5mm Insulated Plasterboard – Insulating Under Rafter
Option C – 1 Layer SuperQuilt, 110mm PIR Insulation, Standard Plasterboard – Insulating Under Rafter
Option D – 1 Layer SuperQuilt, 100mm Phenolic Insulation, Standard Plasterboard – Insulating Under Rafter
Option E – 2 Layers SuperQuilt, 100mm Non Itch, Standard Plasterboard – Insulating Under Rafter
Option F – 2 Layers SuperQuilt, 50mm PIR Insulation, Standard Plasterboard – Insulating Under Rafter
Option G – 1 Layer SuperQuilt, 70mm PIR Insulation, 1 Layer BreatherQuilt, Standard Plasterboard – Insulating Over & Under Rafter
Option H – 1 Layer SuperQuilt, 140mm Rockwool, 1 Layer BreatherQuilt, Standard Plasterboard – Insulating Over & Under Rafter
Option I – 1 Layer SuperQuilt, 75mm PIR Insulation, 1 Layer BreatherQuilt, Standard Plasterboard – Insulating Over Rafter Only
Require a certificate for building control?
If you’re going through building control, it is likely they will want to see a document displaying the achieved U-value. These can be downloaded from our Online U-Value Calculator. Once the form is filled, our system will email the bespoke calculation in PDF form. This can be sent over, or printed off for your building control officer.
Struggling to find the correct calculation? If so, please request a U-value on our Contact Form! Mention the above option (e.g. Option C, or Option D) alongside the m² coverage, we will email a bespoke U-value Calculation and quote.
If you require a solution slightly different, we can also assist – Please email email@example.com
Multifoil’s Direct offer SuperQuilt and BreatherQuilt 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;
All build-ups and suggestions are provided in good faith. Our recommend details should be double checked with building control before committing to a purchase. 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