Derby, New-Build Educational Facility

Project Overview

Background

In 2018, Derby City Council and Derby County Council developed a plan to expand Derby Moor Academy by building a new seven-classroom teaching facility. Intended to meet the demands of a growing location population and to free up space for younger pupils within an existing school building, the £1.5 million scheme would also see the construction of a staff room and office, a reception area, toilets and a plant room.

The standalone premises would be built with a lightweight steel frame and cementitious panels. Upon completion in September 2019, in time for the new academic year, it would accommodate more than 220 students, mostly aged 16 and above.

Brief

The building’s design called for an external wall insulation system that would combine good thermal performance with an attractive finish that would also provide good weather protection. Although the building would be only a single storey in height, the project team specified that a non-combustible mineral wool insulation should be used. In some areas, a textured render would be applied, while in others, coloured brick slips would replicate the appearance of adjacent school buildings.

Design and Specification:

The chosen EWI system comprised:

When combined with Permarock SiliconeUltra K finish and/or with Permarock Brick Slips, Permarock Mineral Fibre EWI systems achieve an A2-s1,d0 reaction to fire classification (EN 13501-1:2018). Such systems may be installed on buildings without height restriction (i.e. including those with floor levels 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. Where the textured render was to be applied, they were installed in thicknesses of 120 mm, and where the brick effect render would be used, the thickness would be 200 mm. In all areas, the boards were securely affixed using both a cement-based adhesive and galvanised steel screws.

Permarock SiliconeUltra K is a lightweight textured render with a nominal 1.5 mm grain size. Offering a typical working life of well over 30 years, it is water repellent, vapour permeable and available in a wide range of shades from the Permarock Colour Chart. It features nano-quartz technology and special preservatives that inhibit organic growth, all of which helps it to maintain a bright, clean appearance without the need for frequent maintenance.

Permarock Brick Slips are supplied as facing bricks and brick corner pistols, each with an approximate thickness of 4 to 6 mm. Made from a flexible synthetic resin, they are lightweight, breathable and highly robust. They are available in 12 standard colours and three textures and can accurately mimic the appearance of many common brick types. In this case, the chosen colour was ‘burnt red.’

Performance and Sustainability

Permarock Mineral Fibre External Wall Insulation systems have low embodied energy and are BIM Level 2 compliant. They exhibit thermal conductivity of 0.036 W/mK, and have an Ecopoints score of 0.10 (m2). This is classified as an ‘excellent’ rating.

Permarock Mineral Fibre insulation is manufactured to EN 13162 and is CFC and HCFC free. It has zero Ozone Depletion Potential and zero Global Warming Potential.

Permarock Brick Slips display very good resistance to soiling and excellent colour fastness. The flat facing bricks measure 215 mm x 65 mm and are supplied in boxes containing 174 pieces. This is sufficient to cover approximately 3 m² of wall surface.

Result:

Assisted by Permarock technical staff, who provided design advice and site-specific training, the installer, Rendserve, completed its part of the wider project on time and on budget. Moreover, the new teaching block as a whole was completed on schedule in September 2019.

The use of both Permarock SiliconeUltra K render and Permarock Brick Slips gave the building an attractive appearance that was entirely in keeping with the others on the site, despite the fact that most of them had been built in 2013. Render was used on the majority of the new block but the brick slips were used to draw focus to the main entrance, and to provide visual continuity with the rest of the site.

The external wall insulation systems have since performed as expected, helping to minimise heat loss in the winter months and to reduce the risks of overheating in summer. The render has retained its clean, white appearance and both finishes have afforded reliable protection against water ingress.

Project
New Build / Education
Client
Derby City Council / Spencer Academies Trust
Substrate
Cement Fibre Sheathing Boards
System
Permarock Mineral Fibre External Wall Insulation Systems
Finish 1
Permarock SiliconeUltra K Finish
Finish 2
Permarock Brick Slips