Guide for homeowners in Inveraray

Repair and Maintenance of Historic Buildings in Inveraray - Home Owners Guide

Inveraray front

Looking after your building  Checklist for your building

What is the Inveraray CARS?

A Conservation Area Regeneration Scheme has been developed with Historic Scotland for Inveraray Town Centre and will run until March 2018. The aim of the scheme is to improve the condition of the built fabric, upgrade and promote maintenance, develop traditional skills and enhance the character of the conservation area. A partnership has been established to develop and run the scheme and comprises Historic Scotland and Argyll and Bute Council.

Scope of the Scheme

Once the grants have been awarded and the work carried out it is vital that this is sustainable in the long term and that building owners, building professionals and contractors understand and appreciate how to maintain the historic character of the buildings. The current draft Conservation Area Appraisal which has been through public and stakeholder consultation will help manage development and decision making. The appraisal identifies the significance and special character of Inveraray and suggests how this can be positively managed.

The need for home owners to carry out maintenance and repair

The repair and enhancement of historic buildings is a key part of the CARS grant assistance for eligible work. The Historic Scotland website:  https://www.historic-scotland.gov.uk contains useful guides on the maintenance of historic buildings.

A further important component of the Scheme is funding upskilling local contractors in traditional building repairs and maintenance techniques. This will help to care for and enhance the special characteristics of Inveraray Conservation Area.

History of Inveraray and its buildings

If you own or occupy a traditional building in Inveraray this guide suggests how you can contribute positively to the regeneration of the town and the improvement of your building. You can download a PDF copy of the homeowners guide here.

View of Inveraray Main Street

Looking After Your Building

The following sections describe briefly the main construction and materials of the buildings in Inveraray and the desirability of retaining traditional materials to enhance the historic value and appearance of the town.

Roofs and Roof Coverings

RoofPitched roofs are constructed of rafters, ceiling ties (beams), struts and wall plates and all should be in good condition. Regular inspections are recommended because if damp and unventilated conditions exist fungal attack can result. Dry rot is particularly damaging. Insect attack can also weaken timber structural members. If roof timbers need treating for dry rot expert assessment is needed so that non-destructive methods and non-toxic applications can be used wherever possible.

Roof apexThe spraying of roofs and other timbers as a precautionary measure is of little value. In many cases the prevention of further water entry and the alteration of the internal conditions by, for example, increasing natural ventilation, may be sufficient to halt timber decay. Specialist contractors should undertake this work. Roof coverings are mainly in natural Scots slate. The replacement of slate with modern man made materials can be particularly damaging and disruptive to the appearance of the town. When repairing and reroofing attempts should be made to source Scots slate or a similar alternative, to match existing. Missing, slipped or broken slates should be promptly replaced to match the original in order to avoid roof leaks.

Broken roof tilesFlat roofs were traditionally covered with lead sheet on superior buildings, or zinc for more general use. Whenever possible these materials should be used for repairs. The detailing of roof lights, dormers, copings and flashing is equally important to the overall appearance of the roof and any change of the original materials should be avoided. In most cases a ceramic ridge tile has been used.

Chimneys and Skews

Chimney stacksChimney stacks (called ‘stalks’), are the parts of the building most vulnerable for weathering as they are generally exposed on all faces. Chimney stalks are usually built in fairface rubble masonry but are often rendered with cement where the stone has decayed. Because of the high exposure and attack from flue gasses the stalks have often been replaced by brick at some time in the past. The junction between chimney stalk and roof is a weak point in the roof covering and any deterioration of the lead flashings or cement fillets here should be repaired promptly.

Chimney stackChimney cans (pots) are generally made of clay and set into a stone cope on top of the chimney stalk and haunched with cement. Skews are the stone cappings to the gable walls against which the slate roof abuts. The joint is formed with a concealed lead flashing, or, more commonly a cement fillet as on a chimney. Skew stones are bedded and pointed in lime mortar on the sloping top of a gable wall and maybe supported at the foot by a shaped stone called a skew putt. The repair of roof leadwork such as copings, flashings, valleys and gutter linings should be designed and installed in accordance with good practice and industry recommendations.

Rainwater Goods

Downpipe and drainRainwater goods includes, rhones (gutters), hoppers, brackets downpipes and shoes at the foot. Cast iron was traditionally used because of its durability. If properly maintained these elements have a long life. Cast iron must be painted to prevent deterioration and all joints       between the various parts should be watertight. Rhones should be cleaned out annually to remove dirt and leaves. All cast iron should be repainted when existing coating starts to deteriorate and in any case at approximately five-yearly intervals. Replacing cast iron with other materials such as uPVC or aluminium is not acceptable. Modern substitutes may have different profiles and different fixings and supports.

Masonry Repairs and Reporting

Traditional masonry walls were built with two ‘skins’ of stone and the core filled with broken stone, lime mortar waste and rubble. The outer layer or face was either random rubble to take a smooth lime render as common to Inveraray, or ashlar (stone blocks with a smooth or textured face, built with fine joints). The inner stone was rubble with wider joints, also built with lime mortar. To the inner face was either just plastered ie “plaster on hard” or in better construction with horizontal timber laths to take two or three coats of lime plaster. The cavity between the laths and the stone face served to allow air movement and the, evaporation of any moisture in the wall.

Prior to about 1900 masonry walls were constructed without damp proof courses. Moisture in the base of the walls can be reduced by lowering of ground levels, improved drainage around the building, and if a timber suspended floor the introduction of underfloor ventilation. Chemically injected damp proof courses are difficult and often ineffective with a wide external wall and holes can be unsightly. Where stone walls have been repointed with a hard cement mortar rather than lime mortar this can accelerate the decay and deterioration of the stone blocks. This work should be carried out by skilled and experienced tradesmen and should match the materials and style of original pointing.

External Finishes

External masonryMany buildings in Inveraray were constructed of rendered  masonry. Maintenance issues especially with regards to gutters and downpipes has resulted in water getting behind the render. The water gets trapped behind the render and with frost action will affect the bond of the render to the stone wall behind. This build up in moisture results in the spalling of the render coat and internal dampness. Staining occurs around downpipes and below gutters. Inveraray is in a highly exposed position  and could be termed a marine environment. Building details must reflect this with particular attention given to the depth of lap for components. Work should be carried out by experienced tradesmen knowledgeable in traditional building construction methods. Technical guidance published by Historic Scotland or other sources should be consulted.

Windows and Doors

Sash and case windowWindow design and proportion are a key part of a building’s character. Replacement of traditional windows with new types and styles can seriously affect the appearance of a building of traditional construction. The majority of original windows in the town were sash and case. These windows provide the maximum amount of daylight through an opening; give controllable ventilation.  Where traditional windows have deteriorated the first recommended course of action is repair. This can be carried out by an experienced joiner. If the building is listed and or in the Conservation Area then formal consent would be required for any change to the appearance of the windows. In all situations replacement with windows in other materials such as aluminium or uPVC is not a suitable alternative. It should be noted that window sections in other materials cannot match those made of timber, the frames and glazing bars (astragals) will invariably be thicker thus reducing the daylight size of the window.

Sash and case windowWindow maintenance should pay attention to the condition of the paintwork and should include regular inspection of the timber cills. Wear in sash cords and shrinkage and wear in the frame can cause draughts. All can be repaired by a joiner with materials to match. The thermal insulation value of sash windows can be improved with draught stripping or secondary glazing, which must be fitted internally. Sash and case windows can be hung on Simplex hinges to allow inward opening for safe cleaning – useful on upper floors. Windows are set into checks in the outside wall and sealed with mastic. Traditionally, mastic was made with burnt linseed oil and fine sand and this is available in either red or buff colour to match the stonework. It should not be painted as the coatings will crack and peel in sunshine. Care should be taken not to damage the mastic when windows are being cleaned or repainted.

Exterior doorEntrance doors to houses in the town are made of timber and are either framed and vertically boarded or, from the 19th century onwards, generally panelled. Doors at the rear are often of a plainer style. As with windows, doors can be repaired by an experienced tradesman and original doors should be retained and not replaced with modern substitutes. Replacement solid flush or glazed doors in uPVC or aluminium are not acceptable as they can adversely affect the appearance, character and value of the building. Original door hardware such as knobs, handles, numerals and escutcheons should be retained. New fittings of a correct pattern and materials are available to replace those missing and modern substitutes are not recommended.

External Paint Finishes

External stepsExterior woodwork such as doors, windows and fascias should be painted with a microporous paint which allows controlled moisture transfer without blistering. All external painted surfaces and materials should be inspected, regularly and redecorated when signs of deterioration are found. This includes rainwater goods, doors, windows and railings which should be maintained in sound condition. Painting waterproofs, protects, and preserves these elements, and enhances the appearance of the whole building. Regular maintenance will keep woodwork and cast iron in good condition, and prolong their life. Painting of parts of a building at high levels is a job for experienced tradesmen.

Boundary Walls and External Surfaces

External railingsStone garden and boundary walls are an important feature of the town and should not be overlooked when building maintenance is being planned. Stone walls, being exposed to weathering from both sides, require more frequent maintenance than house walls, and the materials, form and style of construction are equally important to the character of the area. Regular maintenance and repair should be carried out with materials to match the original. Stone walls should be repointed with lime mortar not cement, as this will prolong the life of the masonry. Copes must be reinstated in natural stone where missing and bedded and pointed with lime mortar. Most town houses are built on the pavement, however where houses are set back or have boundary walls the privately-owned hard surfaces should be maintained in good condition, ensuring that water drains away and that the surface is sound. Effective drainage from paths and paved areas is important to avoid standing water next to buildings, and to prevent the build-up of ice in freezing conditions.

Shop Fronts

Inveraray shopsThere is an interesting mix of shop fronts in Inveraray. Early shop fronts often had quite domestic style openings due to the limitations of construction techniques. Much of the character of a building can be damaged by the replacement of traditional shop fronts by modern alternatives that bear little relation to the historic and architectural credentials and the proportion and details of the building.

Easy Checklist for your Building

Note: this checklist services to inform homeowners what defects may become apparent. In almost all cases repairs should be carried out by tradesmen.

Most of the traditional buildings in Inveraray are built of relatively thick, solid stone walls with a render finish. Originally they would have had a lime render. Some others from the later Victorian Period  are stone ashlar pointed in lime mortar. The materials used in the construction of Inveraray were sourced locally from places often no longer in business and for repairs we either use recycled materials or the closest substitute.

You can also download a copy of this checklist

Roof

Problem

Likely cause

Suggested repair

Loose or missing ridge cappings (usually tiles) Missing slipped or broken slates

Storm damage Nail sickness, physical damage foot traffic

Replace to match. Replace with matching slates or tiles bedded in mortar.

Displaced or failed lead flashings around Dormers, rooflights and party walls.

Storm damage, decayed timber beneath

Check beneath then renew flashings, renew mortar joints at wall junction

Water penetration into roof space, and evidence of staining below. Splitting or buckling of flat roof coverings, flashings failure

Slating defect as above. Decay of timber sarking, aged roofing materials, ponding, apron flashings parting from wall

Repair as above to ensure roof is watertight. Check condition beneath, renew roof and all flashings, provide adequate falls to outlets.

Chimneys

Problems

Likely cause

Suggested repair

Copes and chimney cans displaced, missing or broken

Loose or missing cement haunching; wind damage; natural deterioration

Replace cans to match; renew haunching; fit ventilated cowl if flue is unused

Pointing missing, or cracks in harling

High exposure, aged mortar, stone decay around joints

Renewing pointing in lime/sand mortar; cut out cracks in harl if severe, patch and apply limewash

Plant growth

 Open joints in copes or chimney stalks

Weed carefully to remove roots, treat cavities with herbicide and repoint joints

Lead flashings or mortar fillets at chimney stalks missing or loose

Storm damage, timber decay beneath, theft of lead

Check roof condition, renew lead flashing to match ,repair adjacent slates

Roof drainage

Problem

Likely cause

Suggested repair

Leaks from joints in rhones (gutters) or  rainwater pipes

Bolts rusted, sealant in joints decayed

Clean joints, renew sealant and bolts; touch up paintwork

Rhones sagging, or spilling over after heavy rain

Rafter brackets failed; rhones choked; inadequate falls

Renew brackets, clear rhones, increase falls to outlet

Leak causing rust staining or green (algal) staining on walls

Joint sealant failed

Repair joints and allow walls to dry out. Biocides may be used with care.

Blockages caused by leaves and vegetation

Overhanging trees; plants rooting in rhones

Clear out, cut branches back

Internal signs of damp on plasterwork at ceilings

Generally from roof defects;or internal pipework

Rectify roof as described, check nearby pipework

External walls

Problem

Likely cause

Suggested repair

Loose or missing pointing on exposed stonework

Decayed mortar stone deterioration

Selective repointing with lime/sand mortar

Excessive erosion of stonework, eg at rhones

Long-term saturation; use of cement mortar, frost action

Repair rhones, indent new stones only if erosion is severe, avoid plastic repairs.

Erosion of stonework around hard cement pointing

Cement pointing prevents natural evaporation; stone saturated; frost action

Carefully remove cement and repoint with lime/sand mortar

Excessive decay at foot of wall, especially those close to roads

High moisture content in stonework, also ground water; damaging effect of road salts

Indent new stone if erosion is severe; consider protective coatings; renew pointing if decayed

On harled or smooth rendered walls, cracked, missing or boss (loose) areas

Water penetration behind harl or render, frost action; physical damage; effect of salts

Identify boss areas, cut back to sound surface and apply matching harl or render

 Deteriorating limewash or point finishes, exposing the surface beneath

Sacrificial decay of these protective coatings

Remove flaking coatings to sound base and re-apply in limewash

Heavy organic growth or green staining (algae)

Colonization of algae, on saturated stonework in sunlit areas

Treat only if severe, with environmentally safe biocide repairs may be necessary

Satellite dishes and TV aerials placed in prominent positions

Lack of awareness of the damaging effect on the appearance of the building

Relocate aerials, dishes and cabling to less prominent positions

External

Problem

Likely cause

Suggested repair

Excessive erosion of stone or brick boundary walls; loose copes

Natural weathering; poor quality stone or brick; water damage to mortar beds

Indent new stone or brick only if erosion is causing structural failure; rebed copes; avoid plastic repairs

Missing or loose  pointing

Aged mortar; stone decay around joints

Selectively repoint with lime and sand mortar

Rusting of iron railings and dates and poor paintwork

Breakdown of old paint coatings through weathering; lack of regular maintenance

Clean off iron surfaces to bare metal, prime and repaint with oil-based paint

Surface water not draining from paths; settlement of stone pavings

Pavings laid without falls, or bedding washing-out

Lift pavings, relay sand bed and mortar dabs and re-lay pavings to falls

Blocked or hidden underfloor ventilations

Raised ground or paving levels around walls

Adjust levels to below wall vents; prevent further obstructions

Doors / windows

Problem

Likely cause

Suggested repair

Sash windows won’t slide freely, or drop when in open position

Swollen beads due to decay or water penetration, wear and tear, incorrect sash weights; broken cords

Repair by piecing-in, or with new beads; adjust batton rods; renew weights and cords

Signs of woodrot in cillsor window frames (test carefully for soft wood)

Failure of paint finish through lack of regular maintenance; cill contacting wet stonework

Renew cills (whole rather than part); renew mortar pointing, and repaint

Missing or failed mastic pointing

Natural ageing; effect of sunlight and weathering on previously painted mastic

Renew mastic (linseed oil and sand mix preferred to silicones); do not overpaint

Doors binding:soft wood at foot of door, or physical damage

Timbers swollen due to water penetration through lack of maintenance; wet rot at foot

Allow door to dry thoroughly; (do not adjust width); cut out and piece in decayed sections with timber

Internal

Problem

Likely cause

Suggested repair

Water staining on walls or ceilings, or on roof timbers within roof spaces

Water penetration through roof, valleys or flashings

Overhaul roof; replace defective slats or other roofing; inspect and renew flashings where deteriorated

Excessive condensation on windows (or on wall surfaces)

Reduction in natural air movement in the building; excessive draught-proofing at windows and doors; closed-up chimney

Ensure trickle ventilation; re-open flues; install extractors in kitchens and bathrooms avoid moisture producing appliances; ventilate roof spaces

Water leaks around windows or doors; broken fastenings and handles

Shrinkage of window elements; defective mastic; physical damage; severe exposure

Overhaul windows and repair, renew putty and mastic; renew fastening to match originals

Musty, damp smell especially in enclosed spaces

Woodrot, either dry- orwet-rot; water penetration leading to raised moisture content in timber; lack of ventilation; damp conditions internally; lack of heating

Get report by expert professional; resist proposals to strip all areas merely to get warranty; renew structurally unsound timber; alter internal conditions to reduce moisture levels to below 20% avoid the use of chemicals; introduce ventilation; retain original materials wherever possible

Mould growth on walls, ceilings or beneath floor coverings

 Damp conditions internally, lack of ventilation ; lack of heating

Stop any water entry to the building; lift coverings and expose affected areas to air; dry the building and introduce heating and ventilation; avoid the use of chemicals wherever possible

Splitting or distortion of skirtings, floorboards or window shutters

Possible surface indications of woodrot beneath, due to damp conditions as described above

Investigation by competent professional and proceed as for woodrot above

Failure of paintwork on windows and outside doors

Blistering of paint-work by age and sunlight; condensation from window glass affecting putty; possible timber decay

Remove old paint finishes, repair windows and doors as required, renew putty glazing; and renew paintwork

External paint

Problem

Likely cause

Suggested repair

Split, flaking or dull surfaces on gloss painted windows and doors

Deterioration of old paint systems; damp in underlying timbers; effect of sunlight

Check moisture levels and correct; prepare thoroughly and repaint

Splitting of wood beneath paint, or spongy feel

Possible woodrot due to failed paint coatings

Test carefully with sharp point; cut back to sound material and piece-in with matching timber

Rusting, or paint failure on cast iron pipes

Weathering; routine decay of paint coatings; paint failure aggravated by rusting beneath; physical damage

Clean off iron surfaces to bare metal, prime and paint with oil-based paint

Missing or loose putty on windows and rooflights

Failed paint coatings allow water behind putty; shrinkage with age

Cut out and renew putty; repaint after skin forms

Downloads

Homeowners guide to repair and maintenance  Checklist for your building