JURA limestone will clad the £68m Museum of Liverpool, but only if planning officers are satisfied with durability test results, it was decided yesterday .
The facade of the new waterfront landmark was due to be covered in Travertine marble, but developers opted to change materials after it weathered badly in tests.
A sample of Travertine has laid at the Mann Island site since the museum was given the go-ahead in December 2005.
But a report seen by council planners yesterday said National Museums Liverpool (NML) was concerned about the material’s suitability after it showed extensive signs of weathering and discolouration.
The Travertine had attracted dirt, the surface had stained from water run off, and algae had formed in some of the fissures.
NML said that Jura limestone, by virtue of its dense structure and low porosity, is less susceptible to weathering and more resistant to graffiti.
The planning committee nodded the application to use Jura through only on the proviso council planning officers are satisfied with its performance in tests.
But concern has been voiced because Jura is not as widely-used as Travertine and has not faced as many real-life checks.
A eleventh-hour letter from English Heritage advising Liverpool’s planners expressed surprise at how Travertine faired in the tests.
In the letter, received at 5.15pm on Monday, they wrote: “We would question the validity of the method used to test the Travertine, a tried and tested material, and would advise that the performance of the samples does not itself justify omitting Travertine from the scheme.
“If, however, Travertine is considered inappropriate, Jura may provide a suitable replacement.
“However, Jura is relatively new as a cladding material in the UK and can be a variable material.”
English Heritage recommended more information is gathered about Jura’s suitability before it is used at the world heritage site.
John Cooper, from NML’s agents, Drivers Jonas, told the committee Jura was used on Copenhagen’s Opera House, the United Insurance Building in Munich and on One Cabot Square in Canary Wharf.
The stone has survived on the Munich building for 25 years.
