Sika Liquid Plastics restores the past in York

The York Theatre Royal is set to re-open in spring 2016
The York Theatre Royal is set to re-open in spring 2016
The York Theatre Royal is set to re-open in spring 2016
The York Theatre Royal is set to re-open in spring 2016
Stages of the refurbishment: 1. The original continuous metal rooflights
Stages of the refurbishment: 1. The original continuous metal rooflights
2. The new Decolight Dome and Pyramid polycarbonate rooflights
2. The new Decolight Dome and Pyramid polycarbonate rooflights
3. The new rooflights and Decothane Delta 25 covering
3. The new rooflights and Decothane Delta 25 covering
4. The finished roof with coloured-changing LED lighting (right)
4. The finished roof with coloured-changing LED lighting (right)

Sika Liquid Plastics and BriggsAmasco Leeds have teamed up to deliver the roof refurbishment of the York Theatre Royal as part of a £4.1m re-development project, which required extremely complex detailing around 31 new rooflights.

The area that presented the biggest challenge for BriggsAmasco was the flat roof above the atrium of the theatre, a Grade II* Listed 1967 extension to the building designed by modernist architect, Patrick Gwynne. This roof was of particular concern as it had an original 50 year-old asphalt covering, which had clearly come to the end of its life.

Despite the roof being only 100m² in size, the area had an incredible 31 rooflights to replace and work around. With so many rooflights in a small space, the detailing lent itself to a liquid product, and Sika Liquid Plastics worked alongside BriggsAmasco and building surveyors, W R Dunn, to make sure the roofing solution would be in keeping with the building’s heritage, while offering a stunning new feature in the atrium roof. Sika Liquid Plastics sent a huge sample to the Trust, which included the full rooflight and surround, to make sure that the client was happy with the solution.

The complexity of this refurbishment became even more apparent with the results of the initial survey. It was revealed that an original GRP roof deck from 1967 was hidden under the asphalt – very experimental for its time. The original designs in the RIBA archive showed an intention for glass dome rooflights which would have let light flood into the atrium below. However, the GRP deck must have failed, as it was quickly covered over by a timber roof deck and asphalt, with continuous metal rooflights with Georgian-style wired glass. Sadly, these rooflights only acted as a dust trap, becoming discoloured and offering very little light into the atrium.

Work kicked off in September 2015 to completely strip the roof, taking away the very unusual double build up and existing rooflights and a warm built up roof was installed covered with Decothane Delta 25 – a thermal upgrade that tied in with client’s requirements for improved sustainability.

Thanks to the refurbishment, the original design intention could be realised, with Decolight Dome and Pyramid polycarbonate rooflights installed – making a huge difference to the light in the atrium below. Colour changing LED lighting around the inside of the rooflights also adds a unique feature within the building.

Working to refurbish a roof on a building in the heart of York posed plenty of challenges. Owing to site conditions and proximity to the public, all deliveries had to be made to Briggs Amasco’s premises in Leeds and were then brought onto site on a ‘just in time’ basis. There were also many challenging details and interfaces that had to be overcome. Insulation had to be cut between the rooflights to be installed and the complex detailing was tricky but the liquid applied product made the job much easier.

The teamwork between BriggsAmasco, Sika Liquid Plastics and WR Dunn ensured requirements for sustainability, heritage and aesthetics were met. The refurbishment meant that the original 1967 design intention for letting light flood into the top of the atrium could be realised.

Guy Bowyer, Architect at York Conservation Trust said: “Sika have been excellent, they have had a positive approach from the start assisting us from initial concept stage right through to completion.”

The theatre will feature a new roof, an extended and remodelled front-of-house area and a refurbished and redecorated main auditorium.

gbr.liquidplastics.sika.com