£2 million roof restoration is completed by contractor Beard and architects Purcell
Major works to repair leaks in the glass roof and refresh the interiors of the Oxford University Museum of Natural History have been successfully concluded by regional construction company Beard and architects Purcell.
The museum houses the University of Oxford’s scientific collections of zoological, entomological and geological specimens.
The Gothic Revival museum was designed by architects Thomas Newenham Deane and Benjamin Woodward. The building is characterised by its three dramatic glass and cast iron roofs, four storeys high, which span the main exhibition quad.
Over the past 36 months, the museum has undergone an extensive restoration project to clean and repair its vaulted glass roof and refresh its interiors. The works necessitated that each of the roof’s 8,500 diamond-shaped glass panels was painstakingly removed, cleaned and resealed.
The museum’s vaulted glass roof has leaked ever since it was completed 150 years ago, despite numerous attempts to fix it. The problem was the inconsistent thickness of the sand-cast glass tiles, which were cast to a nominal thickness of 10mm, but actually ranged from 8-12mm. These were nailed to the timber batons in an overlapping design, which created gaps that water could easily penetrate; the overlapping also meant condensation formed beneath each tile.
The problem was the inconsistent thickness of the original glass tiles which were nailed to the timber batons in an overlapping design, creating gaps that water could easily penetrate; the overlapping also meant condensation formed beneath each tile. An effective solution was devised using a mastic silicone adhesive to bond the glass together, leaving small gaps at the bottom to allow the building to breathe and allow any internal condensation to escape.
Over the years, broken tiles were replaced by an assortment of glass types including Georgian wired glass and stippolyte glazing. The unsightly glass infills, along with any irreparable tiles, have been replaced with new slumping kiln glass, or ‘textured glass’, to match their Victorian counterparts.
In addition, the lead has been replaced on the ridge and hips of the three glass roofs and the slate roof has also been re-laid around the roof’s perimeter, extending down to the adjoining Pitt Rivers Museum.
As well as the roof work, the museum interiors required extensive professional cleaning and conservation. Eura Conservation oversaw the cleaning of the glass, the decorated paintwork of the wrought iron and timber rafters, and the laser cleaning of the stone columns.
Discrete light fittings have been installed to the columns and feature lights have been suspended from the former gas lamps by lighting specialists Monard to a design by Zumtobel.
During the works, graffiti was discovered on the timber beams of the roof, thought to have been daubed by the Victorian roof painters. As a gesture to this, the present day project team was honoured with a plaque in the roof.
While the work was carried out, parts of the museum had to remain open and some of the larger exhibits which could not be removed, notably the casts and skeletons of dinosaurs, were protected and left in situ. Many of the specimens have been newly conserved and re-displayed, including the whale skeletons which are suspended from the roof.
Architect, Nick Bradley from Purcell commented: “It has been a real joy to work on this project and the finished results are stunning. For me the highlight was watching the museum be brought back to life when the newly conserved, suspended whale skeletons were raised into their new formation.
Now the glass has been expertly cleaned and repaired, daylight can stream right into the heart of the museum just as the building’s architects, Deane and Woodward, had intended back in 1860.”
“We’ve really enjoyed working with the Oxford University Estates Services, the Museum of Natural History team, Purcell and our subcontractors on this magnificent and unique restoration project,” says Stephen French, Beard Site Manager for the project. “Now with a new lease of life, we hope the Museum’s newly-restored glass-tiled roof will continue to be admired and enjoyed by many generations of visitors to come.”
Paul Smith, director of the Museum of Natural History, said: “This has been a long and involved project that was essential to protect the displays and specimens from leaking rainwater. The building and restoration work presented a unique challenge which Beard and Purcell met with an excellent plan and implementation, working with the University’s Estates Services and Museum staff. I am now delighted to be able to open the doors again to visitors from Saturday 15th February, on schedule and on budget.”
The museum officially reopens to the public on Saturday 15th February.
More information: www.purcelluk.com
