Advice Series. the maintenance and repair of historic buildings

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1 Advice Series the maintenance and repair of historic buildings Jacqui Donnelly - Architectural Conservation Advisor, Department of the Environment, Heritage & Local Government

2 Current publications in the Advice Series ( )

3 Maintenance - a guide to the care of older buildings How old buildings work Maintenance and repair programmes Carrying out a maintenance inspection Dealing with damp Checklists for maintenance inspections

4 Windows - a guide to the repair of historic windows A short history of Irish windows Maintenance and repair of timber windows Maintenance and repair of metal windows Upgrading historic windows Issues concerning replacement windows Checklist of common problems

5 Iron - the repair of wrought and cast ironwork A short history of ironwork in Ireland Maintenance of historic ironwork The deterioration and decay of ironwork Repairing ironwork and planning repairs Common repair techniques Iron and common substitute materials

6 Bricks - a guide to the repair of historic brickwork A short history of Irish brickwork Understanding historic brickwork Identifying problems in brickwork Repairing brickwork Cleaning historic brickwork

7 Ruins - the conservation & repair of masonry ruins Traditional masonry construction in Ireland Approaches to maintenance and repair Common defects found in ruined structures Planning for repair Repair techniques Archaeology and other important issues

8 Conservation principles Understand your building; respect all parts of it regardless of whether or not they are original Use expert, independent advice Don t look at problems in isolation, consider the building as a whole Minimal intervention: do as much as necessary, and as little as possible Avoid conjectural reconstruction unless there is reliable evidence of what it looked like before Repair damaged elements rather than replace them Use the right materials and techniques Changes should be reversible wherever possible Avoid incremental damage Record all repair works for the benefit of future owners

9 Roofs - a guide to the repair of historic roofs A history of Irish roofs Roof structures and materials Cladding materials and methods Identifying and assessing problems in roofs Repairing a historic roof New materials and technologies

10 Irish historic roofs The roof is the first line of defence between a building and the elements Roofs can be difficult and dangerous to access and so are often neglected but regular maintenance of a roof is essential to keep the whole building in good order Historic roofs not only provide a distinctive character and profile to an individual building but also define the character of streets and towns

11 Cladding materials and methods Slate: Irish slate Stone slab Clay tile Lead Copper Welsh slate English slate Scottish slate Corrugated iron Other, including timber shingles; glazing; tarred cloth; asphalt; concrete; asbestos

12 Roof inspection A comprehensive survey of the roof/roofs should be the first step when considering carrying out works: What is it made of? Is it structurally stable? Is it in good condition? Are there distortions and deflections? Do not confine the survey to the exterior of the roof, inside the roof space is equally important and where many defects can be detected

13 Identifying problems Problems with the roof structure: defects in original construction; overloading of structure; timber decay due to insect or fungal attack Problems from previous repairs Decay of the cladding materials Poor original design e.g. lead sheeting Poor ventilation

14 Repairing a historic roof Retain the roof s structural integrity and historic significance Minimise disturbance of the roof Use traditional materials, techniques and carpentry details Record the roof before starting and replicate original details except where they have failed

15 Slate repair techniques Localised slate repairs are preferable to wholesale stripping of roofs Full re-slating is only where there is widescale failure of the covering or the fixings Individual slates can be easily re-fixed and should be attended to immediately Size, colour, texture and thickness of replacement slates are important

16 Roof maintenance checklist Missing slates or tiles Slipped or damaged slates or tiles Slipped or damaged flashings Cracking of sheet materials Blocked valley gutters Moss or other plant growth Overhanging branches Leaks within roof spaces

17 Rainwater disposal maintenance checklist Check that gutters, hoppers, downpipes and gullies are running freely. Need to be cleared at least twice annually Check that gutters are falling the right way and don t sag between brackets Look for any leaking joints in gutters and downpipes Check soakaways are working properly

18 Energy Efficiency in Traditional Buildings What is a traditional building? Building conservation and sustainability Understanding the building Upgrading measures Case studies

19 Energy Efficiency in Traditional Buildings Assessing ways of improving the comfort and thermal efficiency of older buildings Balancing the need to improve energy efficiency while conserving the architectural heritage Avoiding the risks of promoting condensation and mould growth, thermal bridging and trapping moisture within the fabric

20 Traditional Buildings Traditionally built buildings include these features: solid masonry walls of brick and/or stone, often with a render finish single-glazed timber or metal windows a timber-framed roof; usually clad with slate but often with tiles, copper or lead

21 Understanding traditionally built buildings Early builders were aware of the need to conserve fuel and energy sites were chosen carefully; building in sheltered locations; shelter belts of trees and hedging were planted buildings were aligned to maximise solar gain and minimise exposure to prevailing winds the thermal mass of thick masonry walls was exploited to retain heat

22 How modern construction works

23 How traditional construction works

24 Steps to consider 1. Make sure the building is in good repair, well-maintained and dry. Damp building fabric transmits heat faster than dry 2. Take advantage of the existing features of the building for example use window shutters and curtains to retain heat at nighttime. 3. Control draughts for example, repair cracks or holes in the construction, draught-proof windows and doors 4. Include upgrading measures where it can be done unobtrusively for example add attic insulation between the rafters (making sure the roof ventilation is not interfered with); add secondary glazing inside single-glazed windows (where this would not interfere with details such as shutters) 5. Replace outdated services such as boilers with high efficiency units and updated controls

25 Steps to consider cont d 6. Consider the way the building is used. Sometimes it may be possible to re-arrange the location of activities within a building to increase comfort 7. Check if it is possible to incorporate micro-renewables such as solar or photovoltaic panels. Reduce carbon dioxide emissions by using carbon neutral energy supplies 8. The last step should be the assessment of intrusive options such as floor insulation or wall insulation. This will require expert knowledge to assess the potential risks both to the architectural heritage of the building and also to the long-term well-being of the building fabric

26 Attic insulation 25% of heat loss is estimated to be lost through a building s roof Insulating an attic or loft can often be the easiest, most cost-effective and least intrusive way of improving the thermal performance of a historic building Maintaining good ventilation of the roof timbers is essential to prevent insect and fungal (wet and dry rots) attack

27 Attic insulation

28 Upgrading windows Windows are often subject to most pressure for upgrading Yet only an estimated 10% of a building s heat is lost through windows The estimated payback time for installing double-glazed windows is 40 years (compared with only 1 year for draught-proofing existing windows) Image Changeworks Draught-proofing; installing secondary glazing; using existing shutters and curtains can significantly enhance the performance of a historic window

29 Future publications

30 Access - improving the accessibility of historic buildings & places Principles and legislation Preparing to improve access Improving access in the external environment Improving access in and around buildings Providing accessible information

31 Conservation of places of public worship Inspection and maintenance The external envelope of the building Structural considerations Conserving stained glass Interiors and church furnishings Building services Around the building New interventions

32 Thatch - a guide to the repair of thatched roofs Thatch in Ireland Materials and techniques Recording features of thatch Identifying problems Engaging a thatcher and sourcing materials Repair methods Living with thatch

33 Paving the conservation of historic street surfaces Irish paving types and characteristics Planning repairs to historic paving Repair and maintenance of pavements and setts Metal covers, gratings and street furniture Underground utilities Modern interventions

34 Architectural Heritage Protection Guidelines Statutory guidelines for planning authorities Also of use to owners and occupiers of historic buildings and their advisers Available from Government Publications Office ( 10) or to download from