West Bromwich Town Hall and Central Library roof repairs

Background

This large slate re-roofing project is part of a larger £7.5 million initiative led by the Sandwell Metropolitan Borough Council aimed at restoring and renovating the Grade II listed West Bromwich Town Hall and Central Library. The project received government approval in March 2022, with on-site work beginning in August 2023 and completion scheduled for December 2024. The objective of this project is to secure the future of these significant civic buildings and to increase public usage of the facilities.

The main contractor for the project was Morgan Sindall, which appointed NRA Roofing Limited as the specialist roofing contractor. NRA Roofing was responsible for removing and replacing the existing roof covering on this Grade II listed building. The primary suppliers involved in the project were AccuRoof, part of SIG Roofing, providing both SIGA Slate and SR Timber PREMIUM GOLD® Roofing Batten, and Midland Lead.

NRA Roofing is a preferred partner of AccuRoof, part of SIG Roofing, and they collaborated closely with them to create a comprehensive specification for the slate used in the pitched roofing areas of the project. The roofing work began in January 2024 and was completed in September, finishing six weeks ahead of schedule.

Roofing product choice:

The traditional pitched roof was over 150 years old, and the project involved removing the existing slate and installing new materials. SIG Roofing’s design team, AccuRoof, collaborated with NRA Roofing to develop a specification for replacing the heritage roof using like-for-like slate products from the SIGA range, which are supplied by SIG Roofing. The proposed product was the SIGA 112S Spanish slate, sourced from the León region in Spain.

Prior to placing the order, NRA visited the quarry and factory in Spain to ensure that the processes, quality, and availability met the demands of such a large and prestigious project. The slates measured 500 x 250mm and had a thickness of 7mm. This specification was approved, and a total of 44,000 slates, amounting to 2,340 meters squared, were supplied through the SIG Roofing Dudley branch, located close to the project site.

The SIGA 112S is a smooth, dark blue-grey slate that is suitable for a variety of roofing projects. Its resemblance to the slates produced in the Vale of Ffestiniog has earned the SIGA 112S approval from Snowdonia National Park, highlighting its versatility for heritage projects throughout the country. This slate meets the requirements of NHBC, conforms to BS EN 12326-1:2014 – T1/S1/W1, is the first natural roofing slate to pass the Code for Construction Product Information (CCPI) assessment, and is backed by a 75-year warranty. It is particularly advantageous for projects requiring large quantities of slate, especially in planning-sensitive areas or where the cost of Welsh slate is prohibitive.

SIG Roofing also supplied 19,800 linear meters of SR Timber PREMIUM GOLD® Roofing Battens for all the pitched roofing areas of the project. This product meets the specifications outlined in BS 8417:2011+A1:2014 (preservation of timber) and is graded according to BS 5534:2014+A2:2018. Additionally, it is one of the few battens that has passed assessment by the Code for Construction Product Information (CCPI).

More details on the SIGA slate products at https://www.sigaslate.co.uk/ and SR Timber batten at https://sr-timber.co.uk/

Installation challenges:

The contractor faced several installation challenges. Meticulous planning was necessary to ensure the preservation of historical features and aesthetics while also meeting associated standards and regulatory requirements.

Many original features of the roof had deteriorated over time, necessitating careful restoration or replacement with materials that matched historical accuracy while ensuring durability and compliance. Intricate leadwork elements, such as cupolas, finials, and dormers, required meticulous craftsmanship and expert handling to ensure their longevity.

Sourcing the right materials was crucial, like the SIGA 112S slate, which needed to be of high quality and available in ample quantities. The process of roofing was both time-intensive and costly due to the detailed labour, premium materials, and adherence to conservation standards. To preserve the original aesthetics, they used SIGA natural slate, clay-angled ridge tiles, clay two-hole crested ridge tiles, and traditional mortar-bedded ridge and verge. Additionally, they incorporated lead mop roll hips and lead mop roll ridge. All traditional details were installed in compliance with prevailing British Standards and LCA guidelines.

Ensuring waterproofing was seamlessly integrated whilst adhering to conservation guidelines to preserve the original design was also time-consuming and required specialist skills. Further complexity was added when replacing deteriorated rainwater goods with a traditionally styled aluminium system.

In total over 20 trades people worked on the project over the period, so the coordination of multiple trades, including scaffolders, bricklayers, stonemasons and roofing teams, was critical throughout in keeping the project to the agreed timescale. There was also limited space and loading constraints on site, making access and logistics challenging, so detailed planning to maintain safety and prevent disruption was also key.

NRA employed a foreman to oversee daily site activities and ensure tasks were being carried out to the highest standard. Daily meetings with the site team reviewed the tasks for the day. Hands-on leadership ensured that the workflow was aligned with project goals and deadlines. A contracts manager also visited the site weekly to review progress and ensure the project stayed within scope, budget and schedule. Effective project management throughout ensured that the work was completed safely, in compliance with building regulations, within client expectations and ahead of schedule.

Images: 1. SR Timber PREMIUM GOLD® Roofing Batten was used throughout the project