Westminster Hall

 by Elgan Jones

We were kindly invited to join Patrick Duerden, Aliza Ross and Henry Sanders (SPAB Scholar 2012) of Donald Insall Associates on their site inspection of Westminster Hall. It is such a rare opportunity to view and inspect the fantastic 14th century roof timbers up close, which at the time boasted the widest span of any timber truss in Europe. We were also joined by carpenter and timber framer Tom Massey (SPAB Fellow 2014), his father Peter Massey, and structural engineer Robert Bowles.

After a quick frisk through the airport-style security, we stepped into the main hall and gazed in awe at the vast, clear space. Not a single column obstructed our view.

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Donald Insall Associates were overseeing the cleaning, conservation and repairs of the interior masonry walls, which date from the 14th to the early 20th centuries, and roof timbers. Patrick explained some of the logistical constraints of working in the hall, such as the scaffold which, if required, could be taken down and removed in six hours. This partly explained why the works were phased and confined to a few bays at any one time.

Patrick also explained about some of the challenges they experienced in cleaning and conserving the Reigate stone, it is susceptible to decay on exposure to the atmosphere. Sir Christopher Wren once said: “that which is to be most lamented, is the unhappy Choice of Materials”. The performance and quality of Reigate stone can vary greatly depending upon its original bed depth and source. Cleaning methods which could introduce further moisture into the stone were avoided to prevent damaging the stone further. Instead, cleaning systems such a brushing and pyrex latex cleaning were used.

Wk14_Westminster Hall frieze_Elgan Jones

A combination of poulticing and Nano-lime technology was used for conserving the detailed figures within the frieze. Sections of the frieze were conserved using shelter coat and, in order to avoid the uniform flat colour which can often catch the eye, a two coat system was used. Interestingly, the colour of the base and top coat were slightly different so that the top coat could be slightly brushed back revealing the colour of the base coat.

In areas where the decayed friable stone posed a risk to visitors below, the approach was to replace it with Chicksgrove limestone, a more durable stone which aesthetically was a close best match to the Reigate. The profile of the new stone was cut to match the original form and not the current weathered face.

Aliza showing the Scholars sections of the tracery that was failing.

Aliza showing the Scholars sections of the tracery that was failing.

The masonry aspect of the project also includes conservation of the Norman triforium concealed behind the wall’s Victorian stone cladding.

The masonry aspect of the project also includes conservation of the Norman triforium concealed behind the wall’s Victorian stone cladding.

The project also included the cleaning and conservation of the 14th century roof timbers and installation of a new lighting scheme to improve the overall presentation of the Hall.

The great mystery of the Hall is the form of its original roof. Not until the 13th or 14th century could carpenters create roofs significantly wider than the length of the available timber, and so it was assumed that a single or double row of columns was needed to support the Hall’s roof. However, recent archaeological explorations suggest these theories have no foundation and that the roof may have been self-supporting from the beginning.

Sectional through the principal hammer beam showing the dimensions of the timbers. Herbert, C. and Gribble, E. R. (1922) Early English Furniture & Woodwork. London: Waverly Book Company.

Sectional through the principal hammer beam showing the dimensions of the timbers. Herbert, C. and Gribble, E. R. (1922) Early English Furniture & Woodwork. London: Waverly Book Company.

Initially the roof timbers will be vacuum cleaned to remove the build-up of dirt and dust before a closer inspection to examine and prepare a schedule of repair is undertaken. As the scaffold had not long been erected this work had not yet been undertaken however it did give us an opportunity to view the detail and construction techniques of the hammer beam trusses and how the later concealed reinforced steelwork introduced, by Frank Baines in 1914-23, integrated with the historic timbers.

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Hampton Court Palace

Next on the conservation trail was Hampton Court Palace, where the group enjoyed a tour of the impressive roof. The palace started its life as a grand barn with a stone camera (room) that was used in 1236 by the Knights Hospitallers of St John Jerusalem as somewhere to store produce and keep their accounts. Excavations show that the original palace lacked any real residential accommodation. The building, as it stands today, is a mixture of Medieval, Tudor and Baroque architecture. Henry VIII, the palace’s most infamous resident, actually seized the palace from Cardinal Thomas Wolsey. Wolsey had acquired the small manor house on the Hampton Court Palace site in 1514 and built a luxurious palace around it.

Hampton Court Palace roof conservation

Hampton Court Palace roof conservation

Our Scholars and Fellows were introduced to the building’s crumbling Reigate stone (half limestone/sandstone) and the on-site team taught them how to brush away the friable pieces or protect the stone with a lime shelter coat. It is not just modern surveyors who find Reigate stone problematic, in 1713 Sir Christopher Wren described it: ‘That which is to be most lamented, is the unhappy Choice of Materials, the Stone is decayed four inches deep, and falls of [sic] perpetually in great scales.’

The group also learned how to save the live lime ceilings with polyester resin and fibreglass tape. The beautiful diaper (criss-cross) pattern brickwork was dyed to increase the contrast. Andrew Harris, the architect on site, gave them magnets to test the Tijou railings to discern the newer materials from the old. The older railings were made of iron, whereas copper and brass have been used as replacements. Lead paint with linseed oil and turpentine was applied to protect the railings.

Learn more about the conservation work going on at Hampton Court Palace on their website.

Historic Royal Palaces, Hampton Court Palace. Andrew Harris of Martin Ashley Associates: architect, CWO: contractor, William Page: surveyor for Historic Royal Palaces; Clive Dawson: Engineer. Photo from Ross Perkin

Countrywide conservation tour begins

The Painted Hall, Old Royal Naval College

Painted Hall, Old Naval College

From 19-21 March, the Scholars and Fellows were in London for the first leg of their countrywide conservation tour. The group first visited The Painted Hall, Old Royal Naval College in Greenwich for an afternoon of conservation of surface finishes. Described as ‘the finest dining hall in Europe’, the Painted Hall is designed by Sir Christopher Wren and Nicholas Hawksmoor, and painted by Sir James Thornhill. Taking 19 years to complete, the finished Hall was deemed too grand for its original purpose – a dining area for naval veterans.

More than 50 years has passed since the Painted Hall was last restored, accumulated grime and areas of cracking need urgent attention. The Scholars were instructed how to use infrared to identify and reveal previous alterations. The dirty paintings were gently cleaned with de-ionised water and a soft sponge

 The Painted Hall, Old Royal Naval College. Martin Ashley: architect, Stephen Paine: main contractor. Photo from Ross Perkin, SPAB Scholar 2013

The Great Hall, Westminster Palace

The Great Hall, Westminster PalaceTimber, glazing and joinery repairs were the order of the day at The Great Hall, Westminster Palace. The Scholars and Fellows were lucky enough to learn from the expert team on site. Damaged Reigate stone was cleaned using the cleaning agent, arte mundit. The oak woodwork was stained with sulphate from fireplaces, this was gently dusted off. The magnesium limestone was crumbling, loose parts were removed with a soft brush. The cement mortar was removed and repointed with NHL 2, a naturally hydraulic lime. The Great Hall is the oldest building on the Parliamentary estate and has played a pivotal role in British history as all major institutions of the British state were founded around this Hall.

 The Great Hall, Westminster Palace. Adam Watrobski: architect of the Parliamentary Estate, Patrick Duerdan: project architect, Donald Insall Associates, David Carrington, Skillingtons: contractor, Brian Ridout: environmental expert. Photo from Ross Perkin, SPAB Scholar 2013