STROITELI - magazine for building materials and technologiesyear XVII, issue 5, 2020

Layher scaffolding systems receive high praise at Winchester Cathedral

Layher scaffolding systems receive high praise at Winchester Cathedral

With scaffolding in place for up to four years, and visible to 1,000's of visitors over the period, the selection of equipment for works at Winchester Cathedral has had to meet very clear-cut objectives. Blencowe Scaffolding turned to Layher equipment to fulfil a range of access needs in this prestigious building and highlights tidy appearance as one of the key considerations behind the equipment specification.

This factor, together with the speed of erection, were two of the important elements, comments David Blencowe, Director. Scaffold erection in three key areas of the cathedral were addressed initially including a temporary birdcage scaffold constructed in the Presbytery to enable beams to be erected off the high-level clerestory walkways. The installation also features a suspended dust-proof deck, installed beneath the beam level with birdcage access scaffold erected above to provide working access for ceiling and window conservation works.

We also installed external scaffold to provide access for stonework restoration with an additional birdcage erected in the south transept for access to walls and windows for refurbishment and cleaning procedures, he adds. In the latter case, the project also made full use of the Layher Protect system which is proven to provide a highly effective screen against dust and debris of particular relevance in such an important location.

The most recent phase of the restoration work has now called for an innovative and, indeed, spectacular use of Layher's scaffolding and weather protection systems. With the need for protection for a year, the Layher Allround temporary roof structure that now sits over the Presbytery at Winchester Cathedral is impressive by any measure. The use of the Layher equipment, says Blencowe Scaffolding, directly answered many of the specific questions raised at the site. The temporary roof has been constructed to provide protection whilst the existing lead work some dating back 150 years is removed for remelting and replacement, continues David Blencowe.

The cathedral's own roof has an incline of 60 which is accommodated by our building the Layher structure in a series of stepped lifts. In turn, this supports runners for the translucent Keder roofing sheets which were pulled into position over the apex to create a comprehensive weather-proof cover. The lightweight design of the Layher system contributed significantly to the handling and positioning process while its wide-bay design meant that the need to keep ties to an absolute minimum was addressed as efficiently as possible. The roof is located on Layher support scaffolding with ties, where possible, only located after close consultation with the stonemasons, adds David Blencowe. Dating back to the ninth century, today, the layout of Winchester Cathedral exhibits few truly straight lines or square corners, says Ian Bartlett, Construction Manager at the cathedral. Blencowe Scaffolding's view that this would not present problems to the roofing design was fully realised by the use of the Layher system with the speed with which it was erected throughout the cathedral making a major contribution to the programme's scheduling. This has been of particular importance as we need to maintain full public access and use throughout the refurbishment period. Ian Bartlett also draws attention to the in-built rosette connector system which is at the heart of the Layher Allround design. This means there are no separate fittings and thus the risk of material accidently falling from height is significantly minimised. This is both a public safety and building fabric issue, he adds.

The Layher temporary roof framework was fully constructed in the graveyard alongside the cathedral and then craned into position in four lift operations. The precision of the ground level build was critical, says Sean Pike, UK Managing Director of Layher Ltd, as the structure had to match the irregularities of such an old building. The lifting event itself proved something of an attraction for the local population and regional news teams, who turned out in numbers to witness this rarely seen event.

This is clearly an internationally important and iconic structure and one which presents all the challenges that one would expect from a building dating back so far in history, adds Sean Pike. We believe it is a testimony to our temporary roofing system and also to the skills of the Blencowe Scaffolding installation teams that the quality of the resultant roof protection is so high matching, indeed, the excellent Layher access scaffolding that has been installed in other key parts of the cathedral.

Tight timescale requirements had to be addressed throughout the project, not least to accommodate ongoing activities within the cathedral itself. The speed of installation that can be achieved with our scaffolding systems played a major role for Blencowe Scaffolding in this context, continues Sean Pike. He says its versatility and wide bay design also contributed to the efficiency on site the absence of cross-bracing, for example, simplifying movement around the scaffold, particularly for the stone refurbishment works. Perhaps the only thing that is just as impressive, he concludes, is the skill of the workmen who originally built Winchester Cathedral all those years ago.