Palliative or ‘make-safe’ surveys

Again, using small Teams, travelling and working to the latest Guidance and Site Operating Procedures, and with bespoke Safe Systems of Work, we have successfully completed palliative or ‘make-safe’ surveys over the last week or so.

A reasonable proportion of our Projects, whether as standalone work, as part of detailed diagnostic inspections, surveys and investigations, or as follow on services, involve the removal of loose material. Loose pieces of facades, considered to be at immanent risk of falling are brought safely to ground for appropriate disposal, or storage until they can be reinstated.

We have undertaken several Projects where significant quantities of loose material have been removed. These include:

• A large, approximately 1.8m x 250mm x 150mm pre-cast concrete mullion from a 3rd floor window, directly above a city centre street. The mullion had loosened due to a combination of corrosion of the reinforcement within the mullion and corrosion of the steel frame behind (‘Regent Street Disease’), which had essentially pushed the mullion off the elevation.
• The in-situ concrete slab soffit edges, behind a decorative pre-cast façade, where we removed approximately 70kg of loose concrete from over a normally very busy walkway.
• A large, approximately 350mm x 250mm x 150mm x 100mm thick section of tiled in-situ reinforced concrete, from a corner at 5th floor level, above both a city centre street and a glass atrium covering a restaurant. Apart from the risk to pedestrians and diners beneath, we were informed that the cost of replacing a glass panel in the atrium roof, including road closure and cranage would be circa £75k.
• Removal of loose sheet metal covers approximately measuring 1.5m x 1.2m x 2mm thick from the facades of an office block, above a car park. Had the panels come away completely and fallen to ground, with their weight, shape and wind assistance they may have travelled a considerable distance from the elevations, before coming to rest, and had the potential to cause significant injury or damage. The panels had been installed at under-window positions, fixed into place with an adhesive and 4 screws, presumably a belt and braces should the adhesive fail. At ground floor the panels were stuck like the proverbial, but at higher level the adhesive was limited and reliance on the screws greater. Unfortunately, the screws were mild steel and had corroded, with the panels initially vibrating and then rattling, pulling the screws out.

I’m guessing that the means of access used for installation of the panels may have been cradles, with a Clerk of Works uncomfortable at height and less likely to check workmanship too far above ground?

Access for these works was variously abseil, scaffold tower and MEWP, with appropriate permits, pavement closures and cordons to keep 3rd parties and property safe. Loose material was brought safely to ground and not allowed to fall.