The Building Conservation Directory 2021

90 T H E B U I L D I N G CO N S E R VAT I O N D I R E C TO R Y 2 0 2 1 C AT H E D R A L COMMU N I C AT I ON S down to the base of the walls, and can require access equipment such as cherry pickers, ladders as well as contractual help in order that the checks and any work required can be done safely. Working alone on a maintenance check where heights and confined spaces are involved has potential hazards and should be avoided. In all cases it is important to inform others that a maintenance check is under way. Priority should be to external factors that are affecting the brickwork before focussing on the brickwork itself, as there is no point carrying out pointing repairs for example, if gutters, broken down pipes, blocked drains and gullies are still directing water on to the walls. Other factors to take note of are the condition of brickwork where there are hard concrete or paved adjacent surfaces where persistent rain splashing can cause accelerated decay or where external flower beds are raised too high against the brickwork. Chimneys are often out of sight and out of mind, yet these are a potential artery of damp into the heart of the building. Problems here can be as simple as having no cowls on pots, but are often related to cracking of the flaunching on top and decades of erosion of the chimney stack brickwork due to the use of cementitious mortars, and from damaged lead flashings. Coal fires are another source of sulphates, and as salts accumulate on the side where evaporation occurs the most, brickwork may expand on this side causing the chimney itself to curve. It is worth noting that any work required on a chimney cannot be accurately evaluated without close inspection and while a drone can be a useful tool, it is by no means fool-proof. Recording the findings of a maintenance check with a comprehensive set of photographs and site notes is important because it is easy to miss areas of concern, particularly on larger and more complex buildings. Careful planning will ensure you make full use of any equipment and help that has been hired, and it is a good idea to use pre-prepared brickwork maintenance sheets which break down the building into elevations, each with their features detailed. GOOD PRACTICE IN MAINTENANCE REPAIR Works resulting from a maintenance check should be approached like any brickwork conservation project, doing only work that is necessary, retaining original materials wherever possible, and with all aspects considered carefully, including brick and mortar matching, no matter how minor the work may be. Once a list of maintenance issues has been drawn up, the work required should be prioritised and categorised according to skill requirements (to identify those elements requiring non-brickwork skills such as fixing gutters, and those that require brickwork conservation skills, for example). The work can then be planned. Maintenance repairs should be prioritised so that architectural features which are intended to protect brickwork are repaired first. Mortars should always be softer than the bricks to be pointed and building limes selected should reflect not only the era of the brickwork but potentially the degree of exposure it is subjected to. It is a good idea to keep a supply of traditionally made bricks to match the existing ones in size, texture and colour. Brickmakers can and do run out of stock of certain bricks for which there is high demand within conservation circles, so it is worth planning for sporadic repair requirements in advance. Inserting hard bricks randomly selected from a reclamation yard is not a suitable alternative because they can accelerate decay on adjacent brickwork by acting like a water shed or causing water to flow around them on to the softer surrounding brickwork, rather like inserting a piece of granite into a soft sandstone wall. Equally, avoid using bricks whose provenance is not known. Bricks infused with soot deposits or salts for example can affect adjacent brickwork, or if they were intended for internal work, they simply might not be up to the job. Mortars can be prepared at least 24 hours in advance, in fact the longer the better when putty mortars are concerned. When carrying out minor pointing works, jointing would usually be blended in with the surrounding finish by a skilled bricklayer, but where the existing is deemed inappropriate and there is no trace of the original profile, a modern conservation finish may be used with the joint dressed slightly back from the edges of the bricks. Protecting even the smallest repair is important so that the repair is durable and that it does not have to be redone. Bleaching and rapid drying of joints are common problems and lime bloom on brickwork another. Wet pads of hessian or similar can be fastened over even the smallest areas of pointing to help the lime mortar joints cure slowly in this formative stage. When maintenance work has been completed, it is useful to keep a record of what has been done. This can be either in the form of contractor invoices, materials or simply a handwritten check sheet noting the elevation and what has been carried out. In this way, if something does go wrong you can learn from any mistakes. As is obvious from the thousands of Georgian brick buildings found across the country, well maintained brickwork is quite capable of surviving 250 years, despite the idiosyncrasies of the materials and manufacturing processes. If well repaired and maintained they will, no doubt, be here in another 250. TERRENCE LEE is a traditional bricklayer based in Shropshire who studied Historic Environment Conservation at University of Birmingham. He undertakes practical conservation and restoration work (see page 91) and runs short courses in traditional brickwork (see page 173): www.terrenceleeconservation.co.uk . Brickwork repairs to this Georgian farmhouse include localised replacements, pointing with a mortar to match the existing lime-rich mortar, and the replacement of the gauged brick arch seen here on the right, which has been rubbed up ready for the joints to be picked out. Here the author prepares to replace a damaged and defective brick with a new handmade brick of a similar colour, texture and density.