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Historic Environment Building Repair Grants Grants Scheme Advisory Standards of Repair (to be read in conjunction with the ARCH1 report) Revision C 2007 1 Introduction Historic Buildings Repair Grant is In order to attract grant assistance given to assist in the execution of a from Historic Scotland the applicant’s repair scheme on site. It is important Conservation Accredited professional that the repair scheme reflects the adviser should develop repair cautious, studied approach set out proposals to the highest standards in various international conservation of conservation practice using the charters. In particular, the cultural Historic Scotland project-specific significance of the building should not ARCH1 advisory report as the basis be compromised and the work should of the scheme. It is recommended retain as much historic and original that the following advisory standards fabric as possible by minimising of repair are adopted where indicated interventions. Approved repairs to in that report. (Note, however, that the existing fabric should adopt the some advisory standards are not traditional materials, craft skills and grant-eligible.) It is equally important construction techniques found in the that the subsequent works on site are original building. also administered to high standards. Applicants should note that Listed Management of the works to meet the Building Consent procedures and requirements of the Health and Safety repair grant procedures are entirely legislation is the responsibility of the separate systems. It should be applicant, his or her contractor(s) and understood that any proposals to professional advisor(s). alter any part of the building may Historic Scotland should be consulted require Listed Building Consent on detailed points where repair and that Listed Building Consent techniques or use of materials does not necessarily mean that the affects the appearance or integrity of proposals qualify for repair grant. the historic fabric. When preparing Changes to the fabric arising as a the scheme of works, any conflict direct consequence of a conversion between Historic Scotland guidance proposal or change of use is not and emerging site or documentary eligible for grant assistance. Where evidence should be drawn to Historic an historic building or structure is Scotland’s attention and the way conterminous with a Scheduled forward agreed in writing before Monument, Scheduled Monument proceeding. Consent may also be required. 2 Historic Environment Grants • Building Repair Grants Scheme 2 Documents A copy of the relevant tender Scotland as they become available. drawings showing the proposed Documentation submitted to Historic works, specification and bills of Scotland should be kept to the quantities is to be submitted to minimum commensurate with a full Historic Scotland for comment prior understanding of the historic fabric to tender documentation being repair work and other work in context. finalised. Copies of the priced Provide a note of contract period and documents will be required by Historic defects liability period. Historic Environment Grants • Building Repair Grants Scheme 3 3 Costs Tender costs should be summarised 1. Contract preliminaries according to the paragraphs in 2. Contingencies the project-specific report for the building and set out so that any 3. VAT on works future alteration to the costs (with 4. Professional fees explanation) can be compared 5. VAT on professional fees directly with the tendered amount. Figures should also be provided for In exceptional circumstances and the following costs expressed as a where agreed in advance, specialist percentage of the total grant eligible reports such as archaeological work costs for works identified in the or paint analysis may be eligible for project-specific report: grant assistance at Historic Scotland’s discretion. 4 Historic Environment Grants • Building Repair Grants Scheme 4 Scaffolding 4.1 Scaffolding Design 3. A strategy for the insertion 1. When bracing scaffolding, avoid and removal of fixings should the use of damaging masonry be devised before scaffolding is anchors. Consider the use of window erected. Expanded ferrous anchor openings, window jamb cramps, sockets left in masonry will cause raking support or fixing into mortar staining and cracking as they rust joints that are sufficiently wide to and must be removed at the end of prevent damage to adjacent stone the work. Consider rubber sleeved arisses. anchors which can be withdrawn on completion of the works 2. If anchors are required, they must not be fixed close to edges of carved decorative features. Historic Environment Grants • Building Repair Grants Scheme 5 5 Roof and Rainwater Disposal 5.1 Roof Structure 5.2 Slating 1. Ensure the roof structure is sound. 1. Understand the original roof build-up Where there are significant signs of and design the repair, including the use movement in the roof structure, advice of underfelt where appropriate, to suit from an engineer experienced in the the site circumstances. repair of historic structures may be 2. Where different types of slate have required. When designing remedial been used across building phases or structural repairs, adopt a minimum ranges as part of the natural evolution, intervention approach and discuss the these characteristics are to be proposed repair with Historic Scotland. respected. 2. Clear sarking of old nails and lift the 3. Re-slate using sound original slates lowest sarking boards to inspect the recovered from the site together with rafter ends and the wall plate. matching slates brought in as required 3. Inspect timbers for rot, insect to make up the required number. attack and structural weakness. Samples of slate to make up broken Repair damaged timbers using new or unsuitable slates should be agreed preservative treated timbers run to the before purchase. original profile and treat rot or insect 4. Slates to be laid to exactly match attack locally as required. Timbers the original laying pattern using slates of should be spliced in-line rather than the same shape as the originals. cheek bolted (see also 8.2 and 8.3 below). 5. Re-used slates should not be re-dressed as a matter of routine. 4. Where possible, separate timber repairs from damp stonework with a 6. Slates should be fixed with DPC and allow for free ventilation where non-ferrous nails. practicable. 7. Replacement lead flashings, secret 5. Check the provision of ventilation gutters, ridges and other weatherings to to roof voids. If additional ventilation is be lead as described below. required, locate discreetly and create 8. Mortar fillets at skews may be using traditional materials e.g. lead. reinforced with expanded non-ferrous metal reinforcing lath and formed on top of code 4 soakers. 6 Historic Environment Grants • Building Repair Grants Scheme 5.3 Leadwork 5.4 Fired Clay Roof Tiles 1. Weathering to lead flat roofs to be in 1. Understand the original roof new milled or cast lead as follows: construction and repair the timber n cupola astragal cover flashings substructure - including replacement to be a minimum of code 5; felt as appropriate. n flashings, secret gutters, dormer 2. Tiled roofs are normally laid on cheeks etc to be code 6; battens and counter battens (over roofing felt). n valleys to be minimum code 7; 3. Fired clay roof tiles have a limited life n short gutters or small areas of as the tile begins to delaminate, shatter flat roofs without foot traffic may and break down with exposure and be minimum code 7; age. Consequently, older roofs may n all other flat roofs or gutters on require a higher proportion of new tiles. geotextile underlay to be code 8; 4. Replace broken or unsound tiles n ridges to be code 8 and fixed with with new tiles of the same colour, clips of minimum code 8 lead, profile, size and glaze (if relevant). copper or terne-coated stainless steel. 5.5 Asphalt 2. Lead to be laid to follow the recommendations of the Lead Sheet 1. Where an asphalt roof covering is Association. Complex and details damaged and leaking this should be unique to the building should be drawn lifted and replaced with new asphalt at a large scale sufficient to illustrate laid in coats strictly in accordance with how these areas are to be constructed. the instructions of the Mastic Asphalt Council. Sand dusted surface is 3. Flashings are to be inserted into preferred. raggles sufficiently deep to allow the raggle to be pointed. Existing raggles 2. If an insulated asphalt roof is should be used wherever possible. required, solar reflective surfaces and Lead should be isolated from lime insulation are not eligible for grant mortar by a protective coating assistance. Lead overflashings to be detailed in accordance with the 4. The use of sacrificial flashings where recommendations of the Lead Sheet slating discharges into valleys and Association. parapet gutters is encouraged. 5. On flat roofs, hollow roll joints should not automatically be replaced with wood cored roll joints, consideration should be given to the historical context, the roof pitch and any likely foot traffic Historic Environment Grants • Building Repair Grants Scheme 7 5.6 Thatch 2. Corrugated iron used as a roofing 1. There are many types of thatch material or wall cladding should and thatching techniques in Scotland be replaced with new galvanised and these roofs are now a scarce corrugated iron to the original profile and highly valued historic resource. and using fixings to match the original. Repairing traditional thatched roofs requires the most careful investigation 5.8 Stone Slab Roofing and consideration. 1. Record existing stone slab slating 2. A search for archival visual or noting course heights, lap and peg photographic evidence of the building fixing. and its thatched roof will be necessary before works are proposed. 2. Carefully remove existing slabs using best practice and lay aside 3. Recording should include the for re-use. Do not lever out pegs by building type, evidence of changes lifting tails of slabs. Pegs should be in the building use, primary and removed without splitting slabs or secondary roof structures including enlarging peg holes. This may require connections and changes in thatch a higher than usual level of skill and type. workmanship. 4. Archaeological trenching through 3. Re-grade slabs and make up the thatch may help to provide differences in new stone slabs which invaluable information on the make match the source, colour and texture up of the roof and allow the sources of the original. of the thatch materials, including substratum layers, to be identified. 4. Re-fix using newly made seasoned Many thatches survive as an insulation timber pegs of matching species layer under corrugated iron roofs. (traditionally oak). 5. Proposals for the repair of traditional thatched roofs should 5.9 Bitumen Felt Roof Covering follow the original as far as possible and include repair or replacement of 1. Where bitumen felt roof covering structure, substratum and thatch type. was the original and historically correct roof covering on a flat roof, 6. Discuss proposals with Historic modern equivalents such as single Scotland in advance of repair. ply membranes may be considered grant eligible. Perimeter details should remain broadly the same as for the 5.7 Metal Roofs felt original. Note, however, that these 1. Repairs to copper roofs should membranes will not be accepted as replace copper trays by closely a replacement for roofs that were matching the original but with details, originally finished in lead, zinc, copper gauge of copper and underfelt as or mastic asphalt. recommended by the Copper Sheet Association. 8 Historic Environment Grants • Building Repair Grants Scheme 5.10 Rainwater Disposal 5.11 Skylights/Ventilators 1. Check that the existing rainwater 1. Original cast iron skylights are goods are adequate to control and usually sound and should be repaired discharge water safely away from the and reused rather than replaced. building. If not, the professional adviser These are to be painted as outlined for should submit proposals for additional rainwater goods above. installations. Note that alterations may 2. Where replacement rooflights are require Listed Building Consent. required, replace with new rooflights 2. Where cast iron rainwater goods are to the same size, detail and materials. sound ensure they are clear and flowing Modern skylights of the same size freely. and appearance but incorporating 3. Where broken damaged, missing or thermal breaks and alloy castings are in non-original materials such as uPVC, acceptable. replace to match original profile and detail in cast iron. 5.12 Safe Access 4. Ensure maintenance access exists 1. The opportunity should be taken to at ground level. ensure there is adequate safe access 5. Ground drainage to be checked for maintenance and repair. and made fully operational to ensure 2. Where required, provide attic water is being conducted properly walkways to allow safe inspection and away from the building. Digging maintenance of these spaces. within archaeologically sensitive areas such as graveyards may require an 3. Locate access ladders and roof archaeologist. hatches discreetly. 6. All cast-iron pipework and rhones to be prepared, primed and painted in 5.13 Lightning Conductors accordance with manufacturer’s written 1. Lightning conductor systems can instructions using a high performance result in a considerable visual intrusion paint specification. Paint new cast on historic structure; refer to English iron goods before site assembly and Heritage design guide “Lightning make good joints, chips and fixings Protection of Churches” for guidance immediately after fixing. The final colour on discreet design. may be selected using evidence gained in the cleaning process or to match the 2. Fixings should be secured in joints background masonry. rather than stones and conductor lines are to be discreetly located behind or beside other building elements such as downpipes or buttresses. 3. Early lightning conductors may be retained and integrated into the new system. Historic Environment Grants • Building Repair Grants Scheme 9 6 Masonry 6.1 Structural Condition of colour, texture, porosity, crushing 1. Where significant structural strength and weathering properties. movement, settlement cracking or other Advice on suitable new stone to match evidence of a compromised structure existing can be obtained from the is identified, advice from an engineer British Geological Survey. experienced in the repair of historic 4. Remove any redundant fixings, structures may be required. Discuss the surface-mounted cables, television proposed remedial works with Historic aerials and extraneous ferramenta Scotland - including redundant drainage branch pipework. Where services cables or aerials are required, discreetly route 6.2 Masonry Repair them behind internal finishes. This 1. Carefully remove any vegetation services-related work is not grant- while avoiding damage to the masonry. eligible. 2. From the scaffolding, brush down 5. Exposed surfaces of new stone loose stone (with bristle brushes, not should be hand dressed to match the wire) and tap the existing surface to original face or tooling. Avoid the use ensure the face of the stone is sound. of power tools on any exposed surface Where the stone face is eroded or of stone. Cut replacement stone on crumbly but this does not pose a threat the correct geological bed for the to the weathering function (eg cills), the circumstances of its use in different structural integrity or the architectural elements of the building. Lay on a full interpretation of the building, it is mortar bed, grout behind and point fully advisable to leave the stone in place for to ensure loads are taken by the new attention at some time in the future. stone. Indented face stone should have a minimum bed depth of 150 mm. New 3. Where soft, cracked or crumbly stone should not be distressed or toned stones are identified as a threat down to match original. to the structure or weathering, or significantly detracting from the 6. Avoid the use of restoration mortars architectural composition and integrity on face work or margins. Mortar made of the building, they may be carefully from lime, sand and graded matching cut out and indented with a matching stone, may be acceptable for fine stone that respects the existing stone cracks or small “pocket” repairs in joint pattern. Where it is necessary otherwise sound stone and where lying to replace missing, broken, cracked water and subsequent frost damage or eroded stones with new stone, may be considered a risk. ensure that the new stone is a suitable replacement for the original in terms 10 Historic Environment Grants • Building Repair Grants Scheme 6.3 Joints in Ashlar Masonry working back into this space. Pointing 1. Where ashlar masonry is quite tight should be raked out to a minimum with few open joints, avoid re-pointing depth of 35 mm and the joint flushed this masonry. clean. 2. Re-point open ashlar joints by raking out loose or crumbly mortar by hand 6.5 Joints in Rubble Masonry with a hacksaw blade or similar and 1. Where mortar joints in rubble hose joint clean. Angle grinders and masonry are loose or crumbly, carefully power drills must not be used. rake out to a minimum of 35 mm using 3. Wet joints and re-point using putty tools narrower than the joint to avoid lime mortar and fine light coloured damaging the stone. sand. 2. Thoroughly flush clean the joint and 4. Take care to protect the arrises to re-point with the mortar mix informed avoid staining on the ashlar. by analysis (see below). Pointing to be 5. Brush off any loose mortar. Ensure well packed into the joint and finished to stones are not stained by water used to match the original and suit the style of sponge off any mortar residue. Protect masonry construction, including, where pointing while it is curing in accordance appropriate, the correct number of with best practice. pinning stones to maintain the mortar/ stone ratio of the wall indicated in the 6. Do not point open joints which original build. were originally dry built such as some harbour walls or dry-stane dykes. 3. Stones used for pinning repair in rubble masonry should have the same colour, surface treatment and edge 6.4 Removal of Cementitious dressing as the surrounding masonry. Pointing 1. As it can be damaging to the 6.6 Brick adjacent stone arrises to remove well-adhered cement mortar, it is 1. All brickwork repairs to accurately often better to avoid removing sound follow the original build, using brick cementitious pointing. of accurately matching colour, size, hardness and porosity. 2. Where cracked and open or separating from the stone, carefully 2. Following brickwork repair, re-point remove cementitious mortar by the use using a pointing tool and application of fine masonry chisels. Power tools technique similar to that used originally should not be used. with a mortar specification suiting the age of the building and the strength of 3. When free space has been created, the brick. mortar may be freed from the stone by Historic Environment Grants • Building Repair Grants Scheme 11 6.7 Flue Terminals 6.9 Harl/Render 1. Chimney pots to be replaced to 1. Harl or render coats should be match the original form indicated by applied in accordance with traditional documentary or site evidence. Where harling (or throwing) techniques. there is no evidence of the original, Samples of the original harl should be use pots that are in use on buildings of analysed to clearly identify the various similar period in the vicinity. constituents eg shell, aggregate, lime 2. Ensure that the number of pots proportions etc. The new harl should accurately reflects the number of flues. have a wide range of aggregate grading and replicate any local mix or 3. Chimneys not in use should be application traditions. cleared of debris and then terminated with a vented weathered top to match 2. Quality and appearance of work to the pot and a vent at the bottom of be determined by sample panels. the flue to allow free air circulation. 3. Harling/rendering to be applied using a lime mortar mix in 2 or 3 coats. 6.8 Concrete 4. Site operations should ensure 1. Commission an independent that flashings, rainwater goods and investigative specialist report on the external joinery are fitted at the condition of the concrete and repair appropriate time in order to ensure a the structure accordingly. The report good finish to the harl/render. should include such techniques as use of a cover-meter to establish the 5. Where a lined out “ashlar” depth of cover to the reinforcement appearance is to be made, the surface and include core samples at strategic should be pressed flat and the lining locations to enable analysis of the out undertaken to a pre-determined depth of carbonation, chloride content pattern of joints. The ruling tool is to and quality of concrete. be appropriately shaped in order to provide lines of the correct depth, 2. Remedial works may include consistency and cross-section. treatment with corrosion inhibitors and repair of spalling by breaking out poor concrete, cleaning or replacing 6.10 Lime Mortars for Building, reinforcement and repairing concrete Pointing and Harling. to match the original finish. Consider 1. Lime mortars have significantly treating repair locally with corrosion different working properties to cement inhibitor to prevent localised sacrificial mortars. Advice on procedures and corrosion. suitable mixes can be obtained from the Scottish Lime Centre Trust. 12 Historic Environment Grants • Building Repair Grants Scheme 2. All works to be undertaken by fully not eligible for grant assistance. trained masons with experience of It should be recognised, however, historic building work. that biocide is unlikely to have a 3. Lime mortar mix for indenting or long-lasting effect and may damage pointing should match the original the masonry. Consequently, the use mortar and be informed by careful of biocide should not form part of a analysis of original build mortar regular maintenance regime. samples. It should be prepared in advance to achieve maturity and may 6.12 Removal of Paint and Graffiti require a hydraulic content to achieve from Masonry a predicable set and avoid lime leaching. Pozzolanic materials may 1. The use of a paint remover is be added to putty lime mortars to aid acceptable in a grant aided scheme setting. but is not eligible for grant assistance. 4. Where evidence of the original mix does not exist, lime and sand 2. It is necessary to analyse the paint for the mix is to be carefully selected type to establish the least damaging to ensure the mix has a suitable self paint removal method. 2. colour, even if it is to be limewashed. Paint and graffiti removal should be tested and approved for use on that 5. Ensure lime mortar work is particular stone type before approval undertaken in appropriate weather to proceed is given. conditions and protect lime mortar from sun, rain and frost until cured in 3. Chemicals used on stone are to be accordance with best practice. neutralised immediately after use as recommended in the manufacturer’s 6. Earth mortar exists in some early written instructions. or rural buildings. Care should be taken to identify, analyse and carefully reproduce where repair is required. 6.13 Removal of Invasive Vegetation from Masonry and Immediate Vicinity 6.11 Removal of Algae from Masonry 1. The main vegetation trunks are to 1. Where water has caused moss be cut and roots treated with suitable and algal growth on masonry, the area systemic weed killer in accordance is to be scraped clean with wooden with the manufacturer’s instructions. spatulas and cleaned down to remove Larger growths of surface vegetation all organic debris and soil prior to may be cut into smaller areas (creating re-pointing. The source of moisture a grid) prior to treatment. This will encouraging such growth must be identify areas where growth persists addressed in order to prevent re- and allow subsequent treatment to growth. be more selective. More than one 2. The use of a biocide is acceptable treatment may be necessary over a within a grant aided scheme but is period of time. Historic Environment Grants • Building Repair Grants Scheme 13 2. The vegetation adhering to the 3. Limewash should be screened masonry is to be left until dead, and from rapid drying in accordance with then carefully removed by gently best practice. Where the limewash teasing the mat away from the is exposed to drying winds or building taking care to sever roots temperature, repeated wetting of the that penetrate the masonry. Larger screens will be necessary. vegetation should be removed by 4. Layers of limewash should not be hand weeding ensuring that all roots applied if the appropriate attendance are removed to avoid leaving potential to control rapid drying is not possible. open paths for water ingress as they decay 5. Regular maintenance coats will be required over subsequent years. 3. Stones that are found to be loose are to be held in place by wooden wedges until consolidation work is 6.15 DPC undertaken. 1. Installation of new chemical DPCs are not considered grant eligible and 6.14 Limewash should not feature in a grant eligible scheme as the long term effect of 1. Historic limewash can have several chemicals on the masonry is not constituents ranging from natural known. pigments, tallow and other organic additives. As with mortars, analysis 2. Appropriate DPCs may be and sample panels should be carried considered for situations such as out before the specification is finalised. under copes etc. Lead-cored sanded bitumen DPC’s may be preferable to 2. Limewash should be applied to a avoid slip planes. pre-wetted surface. Multiple coats will be required as it should be applied in sufficiently thin coats (the consistency of skimmed milk) to allow carbonation. 14 Historic Environment Grants • Building Repair Grants Scheme 7 Windows and Doors 7.1 Leaded Glazing and Zinc installed with adequate ventilation Camed Glazing at top and bottom. Clear sheet 1. Before beginning a repair to used without mesh gives unsightly leaded or zinc camed windows, a reflections. report should be commissioned from a glass specialist to schedule the 7.3 Joinery works required to bring the window construction into a good state of 1. Windows should be overhauled repair. This report should be sufficiently and repaired wherever possible by detailed to give an outline of the carefully splicing in new matching works proposed with the associated timber to follow accurately the original costs and give a brief outline of the profile using traditional techniques and importance of the glazing and identify glue. any unique attributes that may require 2. Where new replacement windows more in-depth investigation. are required they should be single glazed and manufactured from matching timber sections accurately 7.2 Leaded Glass Protection following the original design and 1. Remove any inappropriate window profiles. protection and make new window 3. Reuse original ironmongery protection in woven or welded non- where possible. Where necessary ferrous or stainless steel wire mesh select historically appropriate new with a pitch and strength designed ironmongery that meets the modern to meet the risk. Meshes should requirements of security and exit, yet be made by a skilled wireworker to is of an appropriate style and quality. accurate templates. Use only slot headed screws. 2. Protection should follow the glass line and not cover stone tracery. It should be fixed using non-ferrous 7.4 Original Glass fixings into joints in the masonry ingo, 1. Original historic glass (crown, back from the outside stone face but cylinder, plate, patterned or coloured suitably spaced away from the glass glass or glass with seeds, reams to give maximum protection. or other notable impurities) should 3. To increase protection in highly be saved for re-use. The use of vulnerable areas, consider safety glass a proprietary putty lamp can be or where weight is an issue, clear valuable in removing old putty without polycarbonate. Clear sheet material damaging the glass. should be fitted behind mesh but 2. Modern cylinder, Vauxhall, crown, not against the leaded glass and be float glass or horticultural glass may Historic Environment Grants • Building Repair Grants Scheme 15 be used for replacements depending 2. Lime mortar pointing placed on the original glass type to be found against a suitable backing stop. Where on the building. These may vary on a a building is harled/rendered the use single building or elevation. of lime mortar to fill this joint will allow 3. Match glass type to original the harl/render to be brought up to examples on site or to date of building the joinery. This should be placed after construction. Any patterns established joinery fascias have been decorated to as a result of evolution of the building ensure good protection of the fascia. should be respected. 3. For late twentieth century metal windows that are a feature of the original design, polysulphide mastic 7.5 Secondary Glazing (not may be used. Proprietary glazing generally eligible for grant) putty is available for glazing twentieth 1. Secondary glazing may be fitted century metal windows. on the inside but this should follow the glazing divisions of the window and not foul or damage any shutters or the 7.7 Painting of external joinery opening of the window. 1. Paint external joinery, using 2. Secondary glazing is not grant traditional methods and using good eligible unless an historic installation. quality oil-based paint including preparation as recommended in the paint manufacturer’s written 7.6 Abutment Pointing instructions. The joint between joinery and masonry 2. Ensure paint is not spread onto is to be pointed with either of the adjacent masonry. following: 3. Window colour to be as original 1. A traditional site mixed mastic from scrapes, or off-white. Avoid comprising burnt mastic sand and brilliant white for pre-1920 buildings. boiled linseed oil placed against a 4. Consider the use of traditional lead suitable backing stop. paints on grade "A" listed buildings. or 16 Historic Environment Grants • Building Repair Grants Scheme 8 Internal 8.1 Plaster repairs 8.4 Decoration (not generally 1. Plaster should be in lime plaster to eligible for grant) match the original as determined by 1. Decoration is only grant eligible where analysis of the existing. it forms part of a historically significant 2. In rooms where lath and plaster decorative scheme. The proposed exists, repairs should be carried out in inclusion of a decorated paint scheme matching materials. should be agreed with Historic Scotland 3. Repairs to rooms or buildings where in advance. the existing lath is lost entirely, may be 2. Conduct a historically researched undertaken in modern materials but this study of the interior. The colour scheme is not grant eligible. should meticulously follow the research findings in colour, decoration, and paint type. 8.2 Joinery work repairs 3. Where interiors are of recognised 1. Carefully record, using profile gauges, historic significance and are sensitive to the original size and form of original UV light, avoid using UV film on historic internal joinery. window glass as this cannot be removed 2. Where it is necessary to repair or easily without risk of damage to the replace internal joinery sections, profile glass. Use UV blinds where possible. new timber of suitable species and Blinds may be grant eligible but should quality to the original profile, cut and fix in be discussed with Historic Scotland in accordance with best practice. advance. 8.3 Rot works 8.5 Services Installations 1. Locate the reason for moisture 1. Heating installations within the getting into the fabric and successfully envelope of the building will be eligible for prevent this happening. Remove rot and, grant at 25% of the grant-eligible cost. where time permits, allow fabric to dry 2. To reduce the risk of electrical out fires, ensure that the scheme of 2. Seek expert advice on methods of works includes testing of the electrical treatment adopting green principles installation and any upgrading found to wherever possible. be necessary as a result of the testing. This is not an historic repair and therefore 3. Carefully patch in new pre-treated not grant eligible. timbers to match original and make good internal finishes to match original 3. In exceptional circumstances refurbishment of decorative electrical fittings may attract grant for repairs but this should be agreed with Historic Scotland in advance. Historic Environment Grants • Building Repair Grants Scheme 17 9 Ironwork The identification of the form of 3. Pure iron has no superior corrosion ironwork to be repaired i.e. mild steel, resistance to steel and should not be cast iron or wrought iron should used in preference to wrought iron for be made at an early stage to guide historically correct repairs. subsequent works. 9.3 Decorative and other Metal 9.1 Cast iron Work Repair 1. Each project should be assessed 1. Weathervanes, roof ventilation and the most appropriate repair louvres, solum ventilators, railings, technique(s) employed given the gates or other historic architectural application, materials and historic ferramenta may be considered for importance. repair as part of the eligible works. 2. In certain circumstances cast iron 2. Flame cleaning; needle gunning may be welded by specialists using or blast cleaning may be appropriate. high nickel electrodes, or brazed Chemical cleaning should be avoided, using aluminium bronze. Plate repairs particularly for cast iron due to the or pinning by drilling and tapping porosity of the material. adjoining components may also be 3. Weathervanes may be gilded. appropriate. Cold metal stitching may also be feasible. 3. Re-casting missing components 9.4 Metalwork Protection. using traditional techniques might also 1. Generally new steel (not cast or be considered. Design and quality wrought iron) should be galvanised should match existing. following manufacture. 2. Suitable long life paint treatments 9.2 Wrought Iron for ironwork, such as zinc rich primers, and micaceous iron oxide 1. Wrought iron should be removed build coats should be considered for for repair by proven experts in this use and applied in accordance with field. manufacturers’ written instructions. 2. To correctly repair wrought iron, Hard shell epoxy paints should not be use only suitable quality recycled used on cast iron; dry film thicknesses wrought iron. Repairing in wrought iron should strike a balance between is preferable to replacing in steel. protection and loss of detail. 18 Historic Environment Grants • Building Repair Grants Scheme 10 Other 10.1 Non Grant Eligible Works 10.4 Sustainability Issues 1. The application should include a 1. Those involved in specification are list of work intended but which does requested to satisfy themselves that not form part of the grant eligible repair the products specified or used in the scheme, together with an indication works will not endanger the health of of costs separately identified from the the consumers or others, will not cause historic repair work, eg electrical work, significant damage to the environment ramps, new WCs or other alterations. during manufacture, use, or disposal, will not consume a disproportionate amount of energy during manufacture, 10.2 Priorities or Phasing use, or disposal, will not cause 1. The remedial works should be unnecessary waste because of over- undertaken in one phase but additional packaging or because of an unusually phases may be considered. The short shelf life, or will not contain cost of the complete works should materials derived from threatened be estimated at the outset and the species or threatened environments. content of each phase should be 2. All timber for the works to be priced and agreed in advance with supplied with written confirmation Historic Scotland. that it is sustainably produced. Large section hardwood timbers to come with the appropriate chain of custody. 10.3 Unforeseen Works Historic Scotland may wish to have 1. It is accepted that unforeseen work sight of such confirmation. may sometimes be necessary. Any 3. Specifiers are encouraged to such work should be clearly identified, ensure that protected wildlife (eg bats) costed and agreed with Historic is not adversely affected by the repair Scotland before being included in the work. works. Historic Environment Grants • Building Repair Grants Scheme 19 Bibliography and Further Information Historic Scotland, “The Repair of Historic Scotland, Guide for Historic Buildings in Scotland” Practitioners Historic Scotland, Technical Advice 1. The Conservation of Timber Sash Notes (TANS) and Case Windows 1. TAN 1, Preparation and Use of 2. Scottish Iron Structures Lime Mortars Revised 2003] Historic Scotland/English Heritage 2. TAN 2, Conservation of 1. Timber Decay in Buildings – The Plasterwork Conservation Approach to Treatment 3. TAN 4, Thatch and Thatching Techniques English Heritage, 4. TAN 6, Earth Structures and 1. Lightning Protection for Churches Construction in Scotland Other useful Contacts 5. TAN 13, The Archaeology of 1. Scottish Lime Centre Trust, Scottish Thatch Charleston, Fife: for advice on lime 6. TAN 15, External Lime Coatings on mortar mixes Traditional Buildings 2. British Geological Survey, 7. TAN 20, Corrosion in Masonry- Edinburgh: for advice on selection of Clad Early Twentieth Century Buildings building stone 8. TAN 24, The Environmental Control 3. Historic Scotland’s Building of Dry Rot Conservation Register: for access to 9. TAN 26, Care and Conservation of a list of consultants, contractors and 17th Century Plasterwork in Scotland suppliers. 10. TAN 29, Corrugated Iron and Other 4. Historic Scotland’s reference library Ferrous Cladding of ironwork pattern books. 11. TAN 30, Scottish Turf Construction Historic Environment Grants Team Historic Scotland Longmore House Salisbury Place EDINBURGH EH9 1SH Telephone: 0131 668 8801 Fax: 0131 668 8788 E-mail: email@example.com
"Building Repair Grants Scheme"