Historic Timber Staircases
Management, Conservation and Repair
The Walnut staircase at Dyrham Park, Gloucestershire, which was constructed in the early 18th century (Photo: Jonathan Taylor, by courtesy of the National Trust)
As well as its obvious functionality, a staircase can be an important part of what makes a historic building special. What should be done when a historic staircase starts to deteriorate or poses an unacceptable level of risk to those who use it? How can the staircase be kept in use without causing harm to those aspects of it which merit conservation?
While it might not be possible to provide a definitive guide to the conservation of any component of architectural significance in the space of a short article, the subject of timber staircases provides a useful vehicle for exploring why one element of a building might be significant in heritage terms. It also affords an opportunity to explore some of the problems that arise through the continual use of a building over a long period of time and the basic approach to identifying the most appropriate conservation measures.
In deciding the best course of action for the management, repair or alteration of any form of historic fabric, it is vital that those involved in the decision-making process understand its heritage significance so that its integrity can be maintained.
The latest approach to assessing heritage significance, as set out in both English Heritage’s and Cadw’s conservation principles requires that we consider four main areas of heritage value: evidential, historical, aesthetic and communal. Not all of these values will necessarily be applicable to the component in question, yet they serve as a useful framework for considering what might make something worthy of conservation.
While assessment of significance has to be considered on a case-by-case basis, it is possible to highlight some key areas in which significance might frequently be identified when thinking about staircases.
Given its function, a staircase often forms an integral element in the plan form of a structure, and as building plan forms have developed over time, the positioning and design of staircases has evolved accordingly. As such, the location and form of a staircase can provide key evidence in dating a building and can help us to disentangle the sequence of development of a complicated structure. It can illustrate an aspect of a typical or unusual historic plan form, and since its position will have shaped circulation patterns, can contribute to understanding how people lived or worked in a particular building. In the same way, variations of style between individual staircases in a building may denote differences in status between different areas and help to identify the ways in which a building was occupied and used. The means by which a staircase is constructed may also demonstrate historic methods of joinery and craftsmanship.
|This simple but elegant late 18th-century balustrade provides a pleasing visual effect. (All photos: Archaeology South-East)|
The fabric of the staircase not only provides the tangible evidence upon which an understanding of it is based but may also yield further information through more in-depth investigation. It is sometimes possible to date a staircase by dendrochronological means but more frequently the potential to learn more lies in concealed historic fabric which may be exposed through repair or alteration work.
Significance might also be derived through association, for example if the staircase is known to have been designed by a particular architect or commissioned by a well-known person or family. It may also derive significance by virtue of its belonging to a particular building.
Where a staircase is not bounded on both sides by a wall, there is an obvious need to provide a safety barrier. The incorporation of a balustrade not only satisfies this basic function but, frequently being located in the main entrance or thoroughfare of a building, also provides the perfect opportunity to use design to impress. As such, there is often substantial scope to ascribe significance on account of a staircase’s aesthetic value.
COMMON DEFECTS, MANAGEMENT AND MAINTENANCE
Most defects are likely to arise through general wear and tear, accidental damage, inadequate control of damp, repeated exposure to fluctuations in temperature and relative humidity, or inappropriate repairs. Many of these risks can be minimised and their consequences delayed through appropriate management and maintenance, which will prolong the structural safety of a staircase and safeguard sensitive historic fabric for as long as possible.
A degree of wear and tear is usually inevitable but the volume of traffic can be reduced in some buildings, particularly those with more than one staircase or where there is the potential to add another one in a less historically sensitive part of the building. If traffic cannot be reduced, other protective measures might prove viable, such as the use of a carpet to form a protective layer. However, care must be taken when choosing and fitting a carpet to avoid causing harm to the underlying structure. An appropriate cleaning regime will also serve to prevent the build-up of harmful agents of decay.
Excessive moisture and poor ventilation can facilitate fungal decay (wet or dry rot) or provide ideal conditions for wood-boring beetles. Particularly susceptible areas include those where a staircase borders an outer wall or a void over a cellar. Good general building maintenance will minimise the risks but some issues, such as moisture in cellars, remain notoriously problematic.
|A decayed stair tread caused by wood-boring beetle infestation||The secondary supports introduced beneath this existing staircase structure have not resulted in any loss of historic material.|
Frequent fluctuations in temperature and relative humidity can exacerbate problems with damp but also lead to problems associated with the drying-out of timber, including loosening of components, splitting and cracking. This is most likely to be a problem where a staircase is close to a main entrance, where the repeated opening and closing of doors to the exterior, coupled with modern central heating is likely to cause frequent fluctuations. The general aim here is to maintain a temperature and relative humidity within a more stable range, which might be achieved by lowering heating controls, or perhaps employing humidifiers or dehumidifiers.
Prior to the late 16th century, most staircases were composed of solid timber or stone treads. Medieval timber staircases characteristically had triangular-section treads but these are now rare and the vast majority of surviving timber staircases are of composite form, with treads and risers formed of individual pieces of timber. These are generally secured by a series of timber wedges which serve to tighten up the individual components. Sometimes these become loose through general wear and tear, or through fluctuations in atmospheric conditions. However, if the underside of the stair is readily accessible it is relatively easy to tighten-up the joints by tapping the wedges back into place.
REINFORCEMENT, REPAIR AND RENEWAL
Even with appropriate cleaning and maintenance, a staircase which is in regular use will eventually need some strengthening or repair work. This is particularly important where the safety of the stair is compromised, for example where treads or nosings are unstable or excessively worn, or where balusters or handrails are damaged.
In accordance with English Heritage guidance, any repair should involve minimum intervention. This will ensure maximum retention of historic fabric but should also reduce the potential for any conflict with building regulations, and in the case of listed buildings may avoid the need to obtain listed building consent.
In some cases the existing structure can be reinforced with no loss of historic fabric. For example, unstable treads can be reinforced through the addition of secondary support. Where possible, any reinforcement should be carried out from the underside of the stair: this might easily be achieved where the structure is exposed, for example in an understairs cupboard, or over a cellar access, but in some cases might require removal of discrete areas of a historic lath and plaster finish. In such cases, the area of plaster removed should be kept to a minimum and should be reinstated in a like-for-like manner. If the underside of a stair is intended to be seen, the sweep of the treads forms an essential element of its design aesthetic so secondary support to the underside is unlikely to be appropriate.
|The replacement of individual components has been achieved here with little or no disruption to the surrounding fabric (note the re-fixed triangular wedges).|
|A typical 18th-century attic staircase, tucked into the
space afforded by the narrowing of a chimney stack: it is
steeply pitched with winding treads and has no handrail
|The aesthetic of this staircase (c1900) has been diminished by the introduction of modern safety measures, including the fire-walls and contrasting nosings.|
Some repairs can be undertaken in situ, for example the gluing of a split baluster or damaged nosing, while other repairs might require the fabrication of new pieces, such as a new baluster or section of handrail, or the insertion of replacement treads and risers. The composite nature of the construction of most staircases means that it should be possible to replace individual treads and risers without undue disturbance of surrounding fabric. It should also be possible to re-fix the triangular blocks that help to hold the treads and risers in place. Where new timber is to be introduced, fully seasoned timber should always be used, as this will minimise the potential for shrinkage and warping which might compromise the effectiveness and longevity of any repairs.
Where components important to the aesthetic of a staircase need to be replaced, it is important that these conform to the existing ones so as not to compromise the overall effect, for example by interrupting the pleasing repetition of a well-designed balustrade. If any required repair or renewal works are likely to involve substantial loss of material, or are likely to radically alter the appearance of the staircase, the conservation officer may require that a written, photographic and possibly drawn record be made of it prior to work commencing. If works have the potential to reveal previously unseen historic fabric, then it might be appropriate to use the opportunity to carry out further analysis and/or recording work.
Issues concerning building regulations typically arise when there are proposals under way to make changes to a building, particularly when these involve a change in use. Compliance with building regulations is often a thorny subject when dealing with historic buildings. Because most historic buildings were constructed by local craftspeople before the introduction of standardised regulations, changes that might be desirable in terms of modern safety standards are often difficult to achieve without compromising those parts of a historic building or component that make it significant in heritage terms.
Building regulations dictate minimum standards for new work, which includes alterations to existing fabric. In England and Wales Approved Document K: Protection from falling, collision and impact outlines the requirements for stairs, including pitch, step construction, headroom, width and length of flights, and requirements for the guarding of stairs, including the form and height of any guarding. The equivalent Scottish building standards are set out in Technical Handbook – Domestic, Section 4 Safety (2013).
Simple vernacular staircases are among the most vulnerable. They often lack a handrail, tend to rise very steeply either as a straight flight, or incorporating half or three-quarter turns, and often have restricted headroom. Because of these traits owners of historic buildings sometimes seek to alter this type of staircase – a proposal that would probably be encouraged by the building control officer but would cause dismay among many conservation professionals.
There is some scope for the relaxation of the requirements of building regulations for historic buildings where doing so can be shown to be necessary in order to preserve the architectural and historical integrity of the building. However, the extent to which the requirements will be relaxed depends on how the staircase is used. For example, if it is in a workplace or publicly accessible building, the potential risks might be deemed greater than in a domestic dwelling. In cases where there are likely to be conflicting issues, early discussions involving both the building control officer and conservation officer can be particularly helpful.
Unfortunately, the many historic staircases in undesignated buildings do not generally enjoy the same level of protection as their listed counterparts so alteration works will usually be subject to the full force of the regulations. In addition, health and safety legislation applies to all buildings, including listed ones, placing on the occupiers of a property ‘a duty to take such care as is reasonable in all the circumstances to see that visitors will be reasonably safe for the purposes for which they are invited or permitted to be there’. In cases where alterations cannot be avoided, modern safety measures such as additional handrails, contrasting nosings and firebreaks have the potential to severely compromise the aesthetic of a stair or result in the unregulated loss of historic fabric which, in the worst cases, might extend to total loss.
NEGOTIATING THE ISSUES
Anyone involved in the conservation of historic buildings will recognise that it is not always easy to find a path through the minefield of competing issues that commonly arise. However, being in possession of good information at an early stage will help to guide the process and allow the impact of any proposals to be evaluated so that the building or component will hopefully remain in use and retain those qualities that make it special.
- C Brereton, The Repair of Historic Buildings: Advice on Principles and Methods, English Heritage, Swindon, 2012
- Cadw, Conservation Principles for the Sustainable Management of the Historic Environment in Wales, Cadw, Cardiff, 2011
- JWP Campbell and M Tutton (eds), Staircases: History, Repair and Conservation, Routledge, London, (forthcoming)
- English Heritage, Conservation Principles: Policies and Guidance for the Sustainable Management of the Historic Environment, EH, London, 2008
- A Jackson and D Day, Period House, Harper Collins/English Heritage, London, 2005
- M Jenkins, Timber Staircases, Historic Scotland Inform Guide, Edinburgh, 2010
- D Urquhart, Conversion of Traditional Buildings: Application of the Building Standards, (Guide for Practitioners 6), Historic Scotland, Edinburgh, 2007