Wednesday, 14 May 2008

Focus on Cladding and Curtain Walling: Stone Cladding

(19 March 2008 00:00)

Szerelmey was the specialist masonry contractor for Paternoster Square, supplying and fitting over 1000m3 of Portland stone.

The outlook for the stone cladding market is at best uncertain. There are several conflicting reports, but while the implications of the global credit crunch are causing everyone distress, it is unlikely that its full effects will be felt in our sector of the building industry for the next two to three years.

Many developers have already committed to schemes that will get the industry through these uncertain times, so in the short-term we expect the majority of contractors' orderbooks will remain full.

Effectively, the situation remains under control, but beyond 2012 it is difficult to say whether this state of affairs can be maintained.

Legislation

Legislation affecting stone cladding has not changed significantly in the past year or so - however changes loom on the horizon. This is inevitable, given the increasing awareness of sustainability issues. BS 8298, the code of practice for design and installation of natural stone cladding and Lining, is currently being revised and one of the more progressive changes will advocate minimising the thickness of stone cladding panels by use of project-specific calculations. This will encourage ever-more innovative fixing methods and produce lighter weight stone cladding façades.

On top of that, it's being widely predicted that CE marking for natural stone will soon come into practice in the UK. The CE Mark is essentially a passport for stone traded within the EU. It indicates that the product complies with the requirements of the 89/106 EU directive on construction products, particularly in regard to health protection and the safety of users and consumers.

This will inevitably increase the price of the cheaper granites and sandstones imported from non-EU states such as China and India. In time, CE marking and its associated costs will level the playing field and benefit UK stone producers. We also expect UK quarries to benefit from the growing concerns regarding the carbon footprint of building materials shipped halfway around the world.

A rough guide

While the future (medium-term) of this market remains uncertain, we can take comfort in the fact that the market is not likely to change radically in the next couple of years.

Below is a general outline of rates for supplied and fixed 50mm thick, hand-set limestone cladding. The rates allow for plain ashlar walling up to approximately 800mm x 600mm with a rubbed or honed finish. Depending on the height from the ground and the fixing specification, the Chamesson and Portland stones may need to be up to 75mm thick. Allow around 26 weeks for stonework design and procurement between placing the order and starting work on site. Prestigious restoration projects may require more time for licensing procedures and consents.