Meeting Part L 2021 Requirements: How Insulfix Track Helps Achieve BREL Standards for Roof Insulation
The updated Part L 2021, which takes effect in June 2022, emphasises that "gaps in insulation can significantly impact heat loss and thermal bypass, increasing the risk of condensation and mould." To meet these standards, the BREL report requires roof insulation to be installed "tight to the structure, without air gaps," and to "extend to the wall insulation."
Both the energy assessor and building control will review the BREL report along with photographic evidence to confirm that insulation has been correctly installed in foundations, external walls, roofs, and around openings. If insulation has already been covered up and issues are found, it can be a costly and time-consuming process to strip back the build and correct these errors.
This article focuses specifically on roof insulation and explains how Insulfix Track can help meet BREL standards.
How to Achieve BREL Standards for Ceiling-Level Insulation
When installing ceiling-level insulation using mineral fibre, achieving BREL standards is relatively straightforward. Mineral fibre insulation is flexible, and as long as it’s cut accurately to fit between the joists, it can be snugly installed without gaps. Adding a second layer to reach the required thickness and U-value is easy, as well-placed edges will mesh together, minimising gaps.
At ceiling level, Part L also notes that the "long-term protection of the insulation layer should be considered: boarded areas should be provided above the insulation for maintenance access." Building control may require evidence showing that these boarded areas aren’t compressing the insulation, as this would reduce its thermal performance.
How to Achieve BREL Standards for Rafter-Level Insulation
Insulating at rafter level is more complex, especially when using rigid insulation boards. Rigid boards lack flexibility, so traditional friction-fitting requires careful measurements to accommodate any deviations in rafter spacing before cutting boards to size. Once in place, any gaps between insulation and rafters must be filled, either by re-fitting or with a suitable gap filler.
Insulfix Track provides a new solution for this challenge. Designed to help achieve tight, consistent insulation between rafters, Insulfix Track insulation fixings minimise gaps, improve air tightness, and lock in thermal performance. Unlike traditional friction fitting, Insulfix Track reduces the need for re-fitting and gap filling, making it an ideal choice for meeting BREL standards.
Managing Gaps in Insulation Between Rafters
According to Part L, unavoidable gaps between insulation boards should be filled with compressible tape or low-expansion foam, depending on the application. However, Part L doesn’t specify how to handle gaps between the insulation and the rafters. Excessive use of spray foam as a filler could be seen by building control as a sign of poor installation, potentially leading to additional inspections or even rework.
With Insulfix Track insulation fixings, these concerns are minimised. Insulfix Track has been specifically designed to support secure, gap-free insulation, ensuring "thermal continuity and quality of insulation" without relying on excessive spray foam or other fillers.
Why Insulfix Track is Ideal for BREL-Compliant Roof Insulation
Insulfix Track is a new, BBA-certified insulation fixing solution tested by the BECCI project at Wolverhampton University, which showed it provides superior air tightness and thermal performance compared to traditional methods. With Insulfix Track, you can:
- Minimise gaps in roof insulation
- Maximise air tightness
- Demonstrate thermal continuity and ensure long-term performance
The BREL report aims to close the performance gap in construction by ensuring that work meets energy efficiency requirements. We believe Insulfix Track is the most effective way to achieve BREL standards consistently.
Moreover, Insulfix Track reduces insulation board waste and has a quick payback period—just 3.7 years, according to the BECCI report. With rising energy costs, this payback period is likely to shorten even further.
For more information on Insulfix Track and how it can help your projects meet Part L and BREL requirements, please feel free to contact us.