Fire Safety Reclad, High-Rise, Leeds Dock
Project Overview
Background
In 2021, Permarock was asked to develop designs for the re-insulation of Magellan House in Leeds – a 12-storey residential block set close to Clarence Dock. The scheme would entail the replacement of an existing cladding system with a view to improving the property’s fire safety, energy efficiency and overall appearance.
Brief
The specification, developed by Axiom Architects, called for a non-combustible external wall insulation system to be installed over a lightweight steel frame and cementitious sheathing boards. Once the original cladding system had been stripped away, the installer – Clear Line Maintenance – would install a mineral fibre system that complied with the latest fire safety regulations.
As part of its planning and design process, Permarock assigned technical staff to carry out site visits to inspect the building and to determine the condition of the substrate. This included pull-out tests to verify that the proposed system could be securely affixed to the boards. The technical team also provided detail drawings, and project-specific installer training.
Design and Specification:
The chosen EWI system comprised:
- Permarock Mineral Fibre External Wall Insulation System with insulation boards adhesively bonded and mechanically fixed to the substrate;
- Permarock SiliconeUltra K Finish (textured render).
Permarock Mineral Fibre insulation is non-combustible. As a combined system, Permarock Mineral Fibre and Permarock SiliconeUltra K achieve an A2-s1,d0 reaction to fire classification (EN 13501-1). Consequently, the system be used on buildings of any height, including those with floors of 11 or more metres above ground level.
The Permarock Mineral Fibre Dual Density Insulation was supplied in boards measuring 1200 mm x 600 mm. The insulation was generally installed to a thickness of 80 mm, although thicker boards were used to complete specific details as necessary.
Performance and Sustainability
Permarock Mineral Fibre External Wall Insulation systems are BIM Level 2 compliant and they feature a thermal conductivity of 0.036 W/mK. They have an Ecopoints score of 0.10 (m2) – which is an ‘excellent’ rating.
The use of both cementitious adhesive and mechanical fixings is a standard requirement for Permarock EWI systems but it is especially important on high-rise schemes. First, it gives enhanced resistance to wind loading and ensures that the system can be specified for use in locations where the wind-driven rain exposure classification is ‘very severe’. Second, it affords additional structural stability in the event of fire.
Result:
The Magellan House scheme met all of the client’s original objectives. With on-site support from Permarock technicians, the EWI system was installed on schedule and helped to improve the building’s appearance. It also produced a weather-resistant façade with excellent airtightness. This, together with the additional insulation, helped to retain heat effectively and to minimise residents’ energy bills.
In 2024, building on the strength of the project’s success, the client asked Permarock to provide designs and support for two further high-rise schemes in the same area: the nine-storey La Salle, and the ten-storey Mackenzie House.
The properties were of a similar construction – fibre cement board over lightweight steel frames – and as with Magellan House project, the premises would remain occupied throughout the duration of the works. For both of the new projects, the specifier would be DLA Architecture. The EWI system specifications would be very similar to the one for Magellan House – i.e. based on a nominal 70 mm thickness of Permarock Mineral Fibre Dual Density Insulation and Permarock SiliconeUltra K finish.
The two schemes were completed on schedule and, again, all targets were met. The system ensured that the properties met the highest fire safety standards, while also improving their appearance and enabling residents to enjoy lower energy bills.
Project
Fire Safey Reclad / Residential
Client
Inspired Property Management
Specifier
Axiom Architects / DLA Architecture
Substrate
Cement Particle Sheathing Board on Steel Frame
System
Permarock Mineral Fibre External Wall Insulation Systems
Finish
Permarock SiliconeUltra K Finish
