An important specialism in stone, especially this year as we mark the centenary of the start of World War I, is the restoration of war memorials – there are estimated to be more than 100,000 of them in the UK.

Most war memorials are treasured but, sadly, some have become neglected and vandalised, or left to suffer the effects of ageing and weathering until they have reached a state where the chiselled epitaph has become difficult to read.

The Alexandra Park war memorial at Crosby, Liverpool, had reached that state when Crosby Memorials, monumental sculptors based in Liverpool, were commissioned to clean and restore it.

The Alexandra Park memorial was unveiled by the 17th Earl of Derby in 1923. It was re-dedicated during this year’s World War I centenary commemoration by the current Lord Derby, the 17th Earl’s grandson and one of Her Majesty’s Deputy Lieutenants of Merseyside. By then it had been sucessfully retored by the masons.

The restoration survey confirmed that the cleaning and necessary redefining of the epitaph message would demand highly sensitive technology and expert masonry craftsmanship to achieve a like-new, high quality appearance.

Stonehealth’s ultra-sensitive DOFF superheated water and steam cleaning system was selected for the work. Doff is a proven system-solution for highest quality stone restoration work like this.

DOFF cleans stonework and masonry using water/steam at temperatures of up to 150°C at the nozzle-end, which removes biomaterial as well as dirt and sterilises the stone so it does not quickly return.

Crosby Memorials is an Approved Stonehealth Rosette Contractor, having taken stringent systems training courses and gained the certification that gains the operators their Operator Identity Cards.

The Rosette approval verifies that contractors are professionally trained to undertake critical and sensitive heritage restoration work to the highest standards of excellence.

The properly trained DOFF operator is able to vary and fine-control the temperature and pressure to carefully remove biological matter and other materials such as paint.

The steam / superheated water eliminates moss, algae, fungi and all other biological matter. And because it also kills off spores, there’s no need to use a chemical biocide during the removal process nor as a protection against further biological activity afterwards.

Because the temperature in the system is high, the pressure on the surface being cleaned is extremely gentle and the water volume low. The surface is therefore not saturated and will be dry within minutes after cleaning.

Crosby Memorials Ltd was founded more than 20 years ago. It has a Board Member on The National Association of Memorial Masons (NAMM), which maintains the standards of working practice in the trade, and is supported by the War Memorials Trust and The National Association of Master Letter Carvers (NAMLC).

Stonehealth Ltd was founded more than 25 years ago. It is a registered RIBA CPD Provider and recognised as an authoritative expert and leading specialist in the provision of holistic restoration solutions for stone and masonry by architects, specifiers and major national conservation and environmental organisations, including the National Trust and English Heritage.

Name this off-grid DOFF and win a bottle of bubbly

Stonehealth has produced a stand-alone version of its DOFF superheated water cleaning system. Its developmental name has been the Stonehealth Power Cell Off-Grid System – simply referred to by Stonehealth as the OGS. But Stonehealth is looking for a catchy name to market it under and is offering a bottle of Champagne for the best suggestion. If you can think of something fitting, email it to info@stonehealth.com.

Why is this machine needed? Stonehealth customers have said that sometimes they find it a problem on-site to obtain a suitable electrical power supply. Stonehealth was asked if it could produce a totally stand-alone machine that just needs water (which could be from a bowser).

This new machine (pictured above) has been specifically designed to provide up to 120Bar water pressure and up to 1.2kW in 240V or 110V. Any DOFF Hotbox that has ever been made by Stonehealth can be used with this machine.

The diesel powered, electric start unit has been designed to use the standard DOFF Jerry can, fuel can bund, and quick fit connections and is supplied as a free standing unit with a plug-in trolley for easy manoeuvrability around site.