This document has been drawn up in consultation with Historic Scotland to assist in the preparation of detailed proposals for the repair or restoration of historic buildings. Its purpose is to provide general guidance as to the quality of materials and standards of workmanship required by the Trust for grant eligibility.

Please read carefully before completing any Grant Application Form.

The Trust's West End Conservation Manual provides much greater detail on the required standards of repair and restoration, and it is recommended that grant applicants consult the appropriate section of the Manual in addition to this document. (See page 4 for a list of the relevant sections.) These higher standards must be met in order for a building repair scheme to qualify for financial assistance from the Trust, regardless of the grant-eligible cost of the proposed works.

Please see GCTW Conservation Grants: Guide for Grant Applicants for more information on the Trust's grant programme.

Walls must be structurally sound and specialist advice should be sought where severe settlement has occurred or where movement of walls is evident. The underpinning of foundations, partial rebuilding, the insertion of structural ties, epoxy resin grouting of cracks or stitching with reinforced concrete bonders in the core are amongst the range of remedial measures which may be necessary. Where lintels have fractured and are failing to carry their load, they should be supported on non-ferrous bars, or, if necessary, replaced in the original material.

Masonry should not be patched in render, nor should dressed masonry normally be rendered if it is currently exposed. Superficially flaking or delaminating stonework should be carefully brushed down using a stiff bristle brush and left as it is. If masonry is seriously decayed, indenting should be undertaken in natural stone, matching as closely as possible the colour, texture and weathering characterstics of the existing stone. Minor damage to mouldings and sculpture is often best accepted as part of the wear and tear of age, but if the damage is such as to spoil seriously the architectural quality of the building, some limited specialist repairs may be possible. Loose and cracked elements may be fixed in place with non-ferrous dowels and/or epoxy. Extensive repairs using epoxy or linostone are not grant-eligible, save in the most exceptional of circumstances.

Open joints in fine jointed ashlar stonework should be pointed with pure lime putty or lime putty mortar inserted into the joints between sheets of acetate. Any sound pointing should be left untouched, and the cutting out of loose putty should be done carefully by hand. Electrical saws, grinders etc. should not be used. Care must be taken to avoid smearing the mortar over the face of the stone, and joints must not be widened to accommodate the mortar in any circumstances.

Rubble work should be repointed by raking out at least 35mm to sound mortar and repointed with a 1:3 lime: sand mix. Care must be taken to recess the mortar into the joint and to avoid smearing it over the face of the stone. Where the masonry has a distinctive pattern of pinnings, it must be carefully respected and not smeared over; pinnings may need to be replaced or renewed.

Wall treatments which are not acceptable include dry dash or cement render, and slaister or bag-rub pointing. Where appropriate, traditional wet-dash lime harling should be used viz a dash coat of lime, grit and sand. Generally, successive coats should be weaker. Local sand and grit should be used, where appropriate. Margins whether raised, flush, backset or chamfered should not be harled over and should be re-exposed where they have been. Where no margins exist, the harl should preferably be rounded into the door and window reveals in the traditional manner. Harling should follow the contours of the stonework rather than being rendered to an even, mechanical surface.

Damp-proofing should be undertaken by specialist contractors, and where a chemical method is employed, drilling should preferably be carried out from the inside to avoid leaving unsightly holes on the external walls. Care must be taken with electro-osmotic methods which can also be visually intrusive; these latter methods should not be used where the stone is clay-bedded. Soil levelling, where necessary, should not be undertaken without professional advice and should respect surrounding archaeology.

Stone cleaning (to remove atmospheric soiling, lamp black, paint or any other applied surface finish)can potentially harm the architectural character and historical integrity of a masonry structure, and may only be undertaken as part of a grant-aided repair scheme with the formal permission of the Trust, based on an approved Method Statement supported by adequate test data. No abrasive cleaning methods, including blasting of any kind or the use of carborundum wheels, will be permitted. If stone cleaning is pursued against the advice of the Trust, it may render the remainder of the work ineligible for grant assistance. Local authority consent may also be required before any stone cleaning is undertaken, and local authority policy on acceptable cleaning methods may vary from that of the Trust.

Local authority consent is required for the painting or repainting of stonework. Generally the painting of exterior stonework is discouraged where it has never been painted, and in some cases removal of paint is the preferred option over repainting. The Trust does not provide grant aid for the painting of stonework, but may contribute to the costs of paint removal in the context of a larger stone repair scheme.

Roofs must be repaired/replaced in materials to match the original, and existing slates, pantiles etc. should be re-used where these are still serviceable. Where the slates have previously been graded, the grading should be reproduced. Non-traditional materials such as concrete tiles or flashings, mineral felt etc, are not acceptable. Inappropriate or mismatching slates should not be used.

All original roof and associated masonry detailing such as crowsteps, skews, skewputts, skewends, gargoyles, decorative water spouts, eaves cornices, blocking courses, parapets, balustrades and associated ornaments should be carefully repaired or replaced in matching natural materials. Decorative features such as brattishing, finials, domes, fleches, decorative roof ventilators, eaves and bargeboards should similarly be repaired or replaced to match, or where they have been lost, carefully reproduced in appropriate materials.

Where roofs require to be completely replaced, the original profile should be retained and the profiles of ogees, bell casts and so on must also be accurately reproduced. Defective sarking or supporting beams must be repaired, or if necessary, replaced to match in treated timber. The roof should be relaid over underslating felt using existing slates, pantiles etc., making up the numbers with matching materials where necessary. Previous distinctive patterns of slating or tiling should be carefully reproduced. Stainless steel or copper nails (not galvanised nails) should be used for fixing.

Replacement flat lead roofs should be relaid in Code 8 lead in accordance with the recommendations of the Lead Sheet Association, following a careful inspection and the appropriate replacement of underlying timbers.

On slated roofs, ridges should normally be in Code 8 lead, but where stone ridges already exist, these should be retained and repaired as necessary. Proprietary fireclay or concrete ridging is not permitted. In certain circumstances, normally in later buildings, zinc may be allowed, provided non-ferrous fixings are used. Flashings should be in Code 6 lead. Fillets and skews should be in cement or secret lead-lined. Lead-lined gutters and valleys should be in Codes 6-8 lead and all should be laid in accordance with the Lead Sheet Association's guidelines, respecting, in particular, their recommendations with regard to maximum lengths and the need for stepped junctions.

On pantiled roofs, ridges should be tiled, skews mortar-filleted, and flashings in Code 6 lead.

Chimneyheads, and, in particular, gable shafted and wallhead chimneys, contribute much to the profile of a building and must be retained or replaced at their original heights, respecting features such as scrolled or shaped haunches, panelling, marginal angles, etc. Repairs or replacements should be undertaken in materials to match the original. Copes in natural stone should retain the original profile and be tied, if necessary, with non-ferrous cramps.

When rainwater goods are being repaired or replaced, the opportunity should be taken of rationalising the piping where unsympathetic accretions have built up over the years. If the present system is clearly ineffective, the opportunity should also be taken of introducing additional piping (for which Local Authority consent may be required). Where the plumbing is original but must be replaced, the original material, section and proportions should be respected and the original fixings reused if these are still serviceable. Particular care should be taken with decorative fixings which have much to contribute to the character of a building. PVC replacements are not acceptable in any context.

Original windows should be repaired rather than replaced whenever possible and if they cannot, an attempt should be made to salvage any original glass for re-use.

When windows have to be repaired or replaced, it is most important that their original qualities are reproduced. Sash windows are the most usual window type, but these take a variety of forms: traceried sashes, lying pane sashes, margin pane sashes, and the larger-paned types of the 1840s, 50s and 60s. After about 1860, a single sheet of plate glass for both sashes became the norm. In late Victorian or Edwardian buildings, however, it was common for the upper sashes still to be astragalled. Where sash windows have to be replaced, it is important to ensure that the replacement windows are fitted in the same plane as the originals, that the sections correspond to the originals as closely as possible, that meeting rails match the original positions and that astragals reproduce the originals in position and section. The painting of windows in historic buildings is also subject to guidelines from the local authority: the recommended colours are white or black, and the colour chosen should correspond with the other windows in the building (eg. in a tenement block, terrace or converted villa).

It is seldom possible to purchase suitable ready-made replacement windows, or for that matter replacement astragals; replacements must almost always be specially made. Where the windows were originally astragalled and have subsequently been reglazed in plate glass to the detriment of the character of the building, it will usually be desirable to replace the astragals, but care must be taken to establish the original pattern.

Modern forms of glazing such as aluminium or uPVC, or timber units which differ from the originals in their methods of opening, are not acceptable. Double glazing, if required, may be introduced by means of suitable internal secondary sashes but these are not grant-eligible.

The same broad considerations apply to other window types, to doors and to decorative fanlights. The original woodwork should be retained and, if necessary, repaired or reproduced exactly. Neighbouring properties of similar type and date can normally provide a guide for appropriate replacements where originals have been lost. Door furniture should also be of a character appropriate to the period of the building. As a general rule, off-the-shelf panelled doors are not appropriate.

All joiner work must be well primed and painted and mastic should be renewed as necessary.

Cast or wrought ironwork in the form of balconies, railings, etc. contributes much to the interest of a building and should be retained and repainted, if sound, and repaired or renewed if damaged or missing. Repairs should be done using materials and techniques appropriate to the original ironwork. Replacement railings must be in the same material as the original and made to a matching pattern; mild steel replacements are not appropriate. Railings must be leaded into sockets in the copings following the original design.

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For further details on the correct methods and acceptable materials to be used in the repair and restoration of historic buildings, consult the following sections of the West End Conservation Manual as appropriate:

Section 1.0 Principles and Practice

Section 2.0 Conservation Law and Finance

Section 3.0 Stonework

Section 4.0 Ironwork

Section 5.0 Domestic Decorative Glass

Section 6.0 Leadwork

Section 7.0 Rot and Insect Infestation

Section 8.0 Historic Parks & Gardens

Section 9.0 Slaterwork

Section 10.0 Historic Wall & Floor Coverings

Section 11.0 Historic Plasterwork

Section 12.0 Historic Streetscapes

Section 13.0 Historic Woodwork

Please note that these TECHNICAL GUIDANCE NOTES may be amended from time to time. It is wise to ensure that the edition you are using is the most up-to-date version issued by the Trust.

Should you require further information, please contact:

Director

Glasgow Conservation Trust West

30 Cranworth Street

GLASGOW G12 8AG

Tel./Fax (0141) 339 0092

glasgowwest@cqm.co.uk

Revised: February 2003