Stone Restoration






New lead capping designed to waterproof the previously incorrectly designed precast stone capping

Contact us if you would like further information on this project info@london-stone.co.uk
DANGEROUS STONEWORK

Defective Stone is falling from buildings regularly. Most failures do not result in personal injury - ‘some do’. The example here in fig 1, illustrates where a section of stone to an upper balcony nosing, weighing approximately 5 kg and having initially fractured due to movement within the iron railing lug, fell onto the opened canvas canopy of a cafe below.

Instructions were issued  to urgently carryout an inspection of all balconies and a subsequent report and quotation was promptly provided. Further failures were identified during this inspection see fig 2 & 3.

The fractured nosing fig 3, fell away with little prompting. The cause of the defect was determined to be caused not only by the corrosion of the iron lug but also due to its location within the weaker front edge of the nosing. Movement caused by thermal expansion of the iron possibly contributed to the failure.

Acting as a Main Contractor we erected a scaffolding and carried out the repairs in accordance with our specification.

Owing to the configuration of the railings and support brackets, it was not possible to successfully indent new stone. We carried out specialist mortar repairs to the failed areas, which when cured, provided an exact colour match to the existing. Note that in order for thermal movement of the railing not to exert any future stress on the repair,
a void was created around the lug which was subsequently sealed with a relatively rigid two part sealant.



PRECAST STONE OF RECENT WORKS

A substantial and alarmingly increasing number of our projects relate to rectification of works previously carried out by others.

This particular railway station actually won a restoration building award in the 1980’s. All the original chimney stacks and decayed natural stone copings were replaced. The latter being substituted with precast stone.
Unfortunately the precast stone had not been properly compacted in the factory and had begun to delaminate some 20 years later. See fig 1. Also the poor detailing of the precast stone chimney capping fig 2, encouraged water to penetrate the structure. London Stone Restoration having carried out a survey, was awarded the contract to replace all copings and springing stone. In order to avoid demolishing the chimneys in order to remove the capping stone, the stone was left in place here and new lead cappings were laid to make them water tight. London Restoration acted as Main Contractor on this project.
The failed stone probably resulted from an inherent defect in the balconies original design

Contact us for information regarding our Specialist Survey Reports
John Dodwell MRICS 07771927444
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All overhanging repairs should be reinforced. This will support the repair during the curing process and beyond.




The solid Kent rag stone walls necessitate extreme care when dismantling the copings.


The design supply and fixing of precast stone wall caps and copings.
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