Conservation & Restoration
Project: The Lady Hungerford Almshouses, Corsham
The Lady Hungerford Almshouses in Corsham was originally built in 1668. The condition of the building was excellent and so only a handfull or repairs and replacements were necessary.
However, there was a high level of work required for the stack and copings as well as the neglected roof. The poor condition of the roof had caused the timbers to rot and thus the gables
had moved. There were several rotted sections within the timber wall plate which the gables were built upon. These rotting sections were replaced by dry packing with a grit sand and hydraulic
lime mortar. There were also decayed rafters supporting the sides of the gables. However, these were left in and were supported by a stainless steel boot. This shifted most of the pressure onto
the wall plate. The masonry forming the gable sides was then rebuilt on the steel work.
Due to the condition of the roof, many copings and apex stones had to be rebedded. We used Limpley Stoke Bath Stone for all necessary stone replacements and indents. The rubble work
at the wall top was loose due to water ingress through the decayed wall plate, which was refixed using hydraulic lime mortar. It was later pointed with the approved site lime mortar. A hydraulic
lime mortar was also used in the pointing of the chimney stacks. Because many of the joints were devoid of mortar, the lime mortar was also tamped into the fine ashler jointing.
The purpose of these refurbishments were to help supply housing for the local community. To maximise accommodation space, we also installed two new window surrounds, one for the Grade I Listed Almshouses and one for the Grade II Listed Parish Rooms. These surrounds were made from Limpley Stoke Top Bed Stone and also fixed with a lime mortar. For more on Restoration and Stone Conservation in Bath, Corsham and surrounding areas, please get in touch.
Osborne House, Corsham
Osborne House is a C18 house in Corsham, Wiltshire. It previously held the title of the dirtiest house in Corsham. The north facing side of
the building is directly joined to a busy narrow road with a junction at the front elevation. This sheltered side of the house is a haven for the
development of carbon, the main cause of the building’s ‘dirty’ look.
Carbon easily adheres to sides of buildings which are not exposed to rain and therefore do not receive a ‘natural clean’. A build up of carbon
inhibits the movement of moisture and minerals through the stone, as it forms a crust on the surface of the building. When the salts try to
escape through the surface of the stone, the pressure gradually builds up and causes decay and a bursting blister of powdery stone. For
these reasons, the removal of carbon from the building was completely necessary. The front elevation of the building was suffering from general
grime and algae growth, caused by the exposure to frost and continual wetting and drying process.
In 2006, Robert Fleming Masonry and Stone Conservation Ltd near Bath were asked to clean and conserve the stone facades of Osborne House. We were also asked to supply and fix Bath Stone copings to the rubble boundary walls. We worked alongside John Harrod of JKH Masonry Cleaning, who cleaned the facades with a Doff System. This system allows us to heat water to up to 150 degrees celsius, in order to instantly kill algal growth and remove grime and paints. After this, the Jos/Torc was used to remove carbon deposits. This system delivers a fine abrasive powder with a small amount of water as well as low air pressure in a rotational vortex, thus removing carbon and other heavy dirt. It also allows us to control the level of clean, as it is not desirable
to over clean a building, as you would expect from blast or water cleaning.
After the cleaning of the building was complete, we started a series of stone repairs. We carried out a number of indent repairs as well as
stone replacements and introduced non-ferrous wire armatures into several larger areas to build up the depth of repair. We used hydraulic
lime, stone dust and sand mix in order to finish these repairs. The cleaning of the building also revealed the use of lime putty jointing,
which we used to repoint various areas of the stonework. This proved to be a challenge, as we encountered many difficulties whilst trying to
produce a consistent white line when so many arises were suffering from decay. In some cases, we found it necessary to mortar repair
across the joints and then later recut a joint so that we could insert the lime putty pointing.
You can see, from the pictures to the right, the fantastic finish of the job at hand. Many thanks to JKH Masonry Cleaning, who we highly recommend for all masonry cleaning projects. You can find out more about them by visiting their website, www.jkhmasonrycleaning.co.uk. For more on stone conservation in Bath, Corsham, Wiltshire and surrounding areas, please get in touch.