Background:

Paisley is the largest town in Scotland, situated seven miles west of Glasgow. Its growth was primarily through textiles, with the town’s name now synonymous with the distinctive textile tear drop Paisley design, a legacy of this growth period. Crowned as Scotland’s Town of the year in October 2025, there has been a resurgence in the town amid recent unprecedented investment for its future.

 The Paisley Museum Reimagined project is one of the largest recent initiatives driven by Renfrewshire Council, to revitalise the historic Paisley Museum into a world-class visitor destination. This project, due for final completion in the second half of 2026, has included the redevelopment of four buildings that make up the site, including two Grade A listed buildings, one of which is Scotland’s first public Observatory. The adjacent building, a former library, has been converted into a new space to house objects from Paisley’s internationally significant collections, and will also include a new red-glazed entrance hall, café, shop, and learning space.

AccuRoof, part of SIG Roofing, became involved in the project at its conception in early 2020, during the Covid pandemic, working closely with the building surveyors to assist in the specification of the roofing product. They collaborated extensively with the Tier 1 contractor Kier to develop the specification and a detailed sequencing plan, ensuring a structured approach to the roofing process.

John Fulton Plumbing and Roofing’s were appointed to work on the Oakshaw buildings and Main Paisley Museum buildings and work commenced in 2021 completing in 2025. The re-roofing of the museum has been a crucial part of the restoration effort to ensure the preservation and enhancement of this historic structure.

Roofing product choice:

Paisley Museum is a Grade A listed building. Any materials chosen for the project therefore, had to not only go through planning approval, but also Scottish Heritage Trust and National Trust Scotland. On this project, there were 64 roof areas in total, and approximately 46 were completed in slate.

The primary products used in the reroofing included:

• Salvaged existing slates
• SIGA120 slate sourced from the Cwt-y-Bugail quarry in Wales, which comes in 5 lengths & 3 widths to attain the random diminishing install on the roof. This slate is an ideal alternative to the indigenous Scottish Ballachulish slate, which hasn’t been quarried since 1955. The whole roof slates used on the project had to look similar in colour
• Welsh slate Cwt-y-Bugail 500mm x 250mm county blue/grey. Pre-holed 150mm due to low pitch
• Novo Black Breathable Membrane, 30mm Isolair wood fibre insulation and Nickleson LB30 and LB40 Airtrack Vents were essential for modernising the roof’s functionality, improving airflow and U-values in the building.

All products supplied by SIG Roofing for this project qualified for coverage on the SIG Roofing One Warranty scheme, a comprehensive, third-party 15-year warranty covering the performance of all the specified roofing products installed, with one simple registration process.

Challenges:

The big challenges were the material selection, accessing the difficult roof elevations and the restrictions for SIG Roofing on the delivery of materials to site, especially with fixed delivery access times and the stock management of two different slates on such a tight town centre site.

Once the roofing contractor had stripped the roof, there were only enough salvaged slates to complete two of the roof sections. This meant that the rest of the roof spaces had to be completed in new slate. However, due to the pitch of the different roof areas, this required a mix of new slate materials. Three of the roof elevations were completed in Welsh Slate Cwt-y-Bugail 500mm x 250mm County Blue/Grey Pre-holed 150mm due to low pitch. The slates are a suitable replacement for the Ballachulish, but the larger slate size was critical for performance due to the headlap on the roof pitches.

The remaining roof elevations, which would be visible to the public, had to make use of a product which closely resembled the indigenous Scottish Ballachulish slate. For these areas, Accuroof specified SIGA 120 Random 14-10 inch long slates. These slates are blue-grey in colour and match the appearance of historic Scottish slates, ensuring visual continuity. The use of random widths added to the authentic look, ensuring that the roof remained true to its historical appearance.

Installing the slates required meticulous planning and execution due to the building’s historic nature, architectural intricacies and the scale of other work being undertaken on the site. The project involved 64 different roofing elevations with various interfacing elements, such as mansard panels, top panels, asphalt gutters, zinc overflashings, gutters and ridges.

Whilst accessing the main roof of the building was relatively straightforward, of the 64 roof areas, only 15 could be easily scaffolded. The remaining elevations were landlocked by a neighbouring building or gables, which required intricate sequencing.

Workmanship

The roofing contractors initially had to completely strip all the roof spaces right back to the timber rafters before installing the insulation and airtrack vent wings. Due to salvaging original materials, a significant element of the preparatory work involved examining the material before determining what was viable for re-use. This included the original sarking which the roofing contractor took off, cut back and then put back in again where possible.

With the existing Ballachulish slate material, the roofing contractor stripped off the slate, redressed, hammered, carefully checked the slate before storing it safely. Historic Environment Scotland (HES) determined which elevations on-site were to be re-slated with the salvaged slates. Due to its aspect facing the high street, they decided that the salvaged slates were to be used on the front of the main Paisley Museum building and the Oakshaw Buildings. The roofing contractors could then grade the slates and sort into different thicknesses (thick, medium and thin) and then re-holed before putting back on with thicker slates at the eaves and thinner slates at the ridge.

The new SIGA 120 and Cwt-y-Bugail blue-grey slates were used on the remaining roof pitches.

Summary

The success of the roofing project can be attributed to the expertise of the contractor, John Fulton (Plumbers) Ltd, and the support from AccuRoof providing specialist specification advice from conception of the project design. SIG Roofing played a crucial role in procuring and storing the slate, ensuring just in time delivery to suit the project delays encountered on the landlocked town centre site. The continuous collaboration between all parties (Main Contractor, Sub-Contractor & Supplier) to analyse and provide quick responses to any challenges that arose.