SURVEY REPORT

YEW TREE COTTAGE, WASH WATER, BERKSHIRE

Oxley Conservation Ltd 8a Friday Street Henley on Thames Oxfordshire RG9 1AH

Telephone: 01491 414191 Email: [email protected] Website: www.oxleyconservation.co.uk Survey Report Yew Tree Cottage, Wash Water, Berkshire

CONTENTS

CONTENTS ...... i 1 THE REPORT ...... 2 1.1 The Client ...... 2 1.2 The subject building ...... 2 1.3 Instructions ...... 2 1.4 Date of inspection ...... 2 1.5 The limitations of the inspection ...... 2 2 INTRODUCTION - THE ADOPTED APPROACH ...... 2 3 VERNACULAR BUILDING SURVEY ...... 3 4 CONDITION SURVEY ...... 4 5 RECOMMENDATIONS FOR REPAIR ...... 6 6 BUDGET COST ESTIMATES ...... 8 7 WILDLIFE ...... 9 8 LIMITATIONS ...... 9 8 SELECTED PHOTOGRAPHS ...... 10 APPENDICES ...... 15 Appendix 1: List Description ...... 15 Appendix 2: Implications of listed status ...... 17 Appendix 3: The traditional performance of old buildings ...... 18 Appendix 4: The qualities of lime based materials ...... 20

Oxley Conservation Ltd i of 20 April 2017

Survey Report Yew Tree Cottage, Wash Water, Berkshire

1 THE REPORT

1.1 The Client

The National Trust, Micheldever Consultancy Hub, 4 Warren Farm Barns, Andover Road, Winchester S021 3FL

Contact: Jessica Mittler

1.2 The subject building

Yew Tree Cottage, Andover Road, Wash Water, Newbury RG20 0LT

1.3 Instructions

Yew Tree Cottage was inspected in accordance with the written instructions to provide the following:

1. Vernacular Building Survey; to include a brief analysis and interpretation of the development/phasing of the building. 2. Condition Survey; concentrating on the readily and safely accessible areas of the roof structure and the chimney stack. 3. Recommendations for repair.

1.4 Date of inspection

30th November 2016.

1.5 The limitations of the inspection

This Report is based upon the following limitations:

o A non-destructive inspection of the readily accessible and visible areas of Yew Tree Cottage; concentrating on the roof structure and the chimney stack. o The services have not been inspected or reported upon for the purposes of this Report. However, a general observation has been made within the report relating to the number of electrical power points available [item 5.9]. o Extensive wall linings prevented a full inspection of the walls and associated detailing. o This report is not a specification for the execution of work and must not be used as such. The report is restricted to the development and condition of Yew Tree Cottage.

2 INTRODUCTION - THE ADOPTED APPROACH

This Report is review of the development and the condition of Yew Tree Cottage, which is a Grade II listed building [Appendix 1]. Consequently, the recommendations made in the Report are based upon a conservation minded approach that is considered appropriate to a building that is listed as being of special architectural or historic interest.

The recommendations rely upon constructional methods of repair, using materials compatible and consistent with the historic fabric, and, wherever possible, repair techniques that are reversible and that maximise the retention of the surviving historic fabric.

This Report is the initial assessment of the condition of Yew Tree Cottage, with particular attention to the roof structure and the chimney stack. Without further investigation and opening-up of parts of the fabric the full extent of the problems, particularly structural detailing and/or timber decay, cannot be ascertained.

Oxley Conservation Ltd 2 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

3 VERNACULAR BUILDING SURVEY

3.1 Brief description

Yew Tree Cottage is a Grade II listed detached cottage located in a rural location adjacent to the A34. The cottage is located on the eastern edge of the North Wessex Downs Area of Outstanding Natural Beauty [AONB].

The front of the cottage faces east and comprises of a single pile two cell principal range with a rear [west] outshut to the west providing ground floor service accommodation and a first floor landing/attic area. There is a basic lean-to timber-framed outbuilding to the north flank elevation [Photo 4].

The walls are constructed in solid 9 inch or single skin [4 inch] brickwork primarily in a Flemish bond; alternate stretchers and headers. The headers are glazed/burnt and add considerably to the appearance and charm of this simple cottage.

The roof is pitched with a ‘cat-slide’ roof to the rear [west] extending from the principal range and over the outshut [Photo 2].

The roof timbers are consistent with a single phase of construction, comprising of softwood, most probably larch, ‘pole’ rafters and collars and a pair of central oak ‘principal’ rafters with, where visible, elm ceiling joists [Photos 5-7].

The cottage is provided with protection against the prevailing elements, south westerly driving rain across the Downs, with tile-hanging to the first floor of the south facing gable [Photo 3]. The west facing outshut minimises the area of the wall exposed to driving rain, as the first floor accommodation is protected by the ‘cat-slide’ roof [Photo 2].

3.2 Analysis of development

The brickwork to the ground floor wall to the south elevation [Photos 3 & 15] does not show any break in the bond or any other indicators that this wall was constructed in two phases. There is a ‘build-line’ or difference in the bond to the first floor of the north elevation [Photo 12] but this is not evident at ground floor level. It is unlikely that the north and south walls have been completely rebuilt. Consequently, the principal range and the rear outshut are of a contemporary single phase of construction.

The layout of the first floor plan requires access to be gained to the first floor accommodation using the stairs contained within the rear outshut.

The doors and the door furniture to the first floor rooms, the bedrooms, within the principal range are consistent with the age of the early 19th century origins of the building.

The winding stairs are also consistent with those that would be found in similar buildings of the early 19th century of this status.

The evidence available at the time of the inspection strongly supports that the building was constructed in a single phase, with the rear outshut providing the service range, including a scullery, and a means of providing access to the first floor accommodation.

3.3 Summary of development

Yew Tree Cottage was constructed in a single phase and is of a building type that is not uncommon; providing simple yet functional accommodation.

Oxley Conservation Ltd 3 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

4 CONDITION SURVEY

In accordance with the instructions Yew Tree Cottage was inspected to concentrate on the condition of the roof structure and the chimney stack. However, some other areas of concern have been reported upon below:

4.1 Roof structure

The roof structure shows no signs of immediate failure. The purlins and rafters showed no excessive undulation or sagging.

The lateral restraint, provided by the ceiling joists, between the front and rear slopes of the roof needs to be confirmed by lifting of the insulation. It is anticipated that there will be the need for some improvements to the lateral restraint.

There is reported sagging of the roof, this was, however, not deemed to be of sufficient concern.

There is no significant evidence that the roof is suffering from a lack of lateral restraint and contributing to the movement noted to the east [front] wall [4.3.2].

The roof coverings are in need of stripping and recovering [Photo 9], even though the southern end of the rear slope has been recently recovered. Stripping the roof would provide the opportunity to review and, where found necessary, improve the constructional detailing of the roof, improve insulation and provide a sound and water- tight roof for the foreseeable future.

4.2 Chimney stack

The south chimney stacks leans to the south, into the prevailing weather [Photo 10]; this is a common ‘defect’ caused by a combination of weathering, deterioration of mortar caused by the by-products of combustion and salt crystallisation. Based upon the ground level inspection the south stack is not considered to be in need of urgent repair. It will, however, require above average levels of repair and maintenance to reflect its exposed position.

When the roof is recovered, as recommended, both chimney stacks should be closely examined and repaired as found necessary together with improved detailing, such as the provision of lead flashing abutments or tiled mortar fillets with concealed lead soakers [Photo 11].

4.3 Structural movement

4.3.1 Clay sub-soil

Reference to the British Geological Survey Quaternary Map shows, albeit not conclusively at a scale of 1:625,000, clay-with-flints deposits in the vicinity of the subject building. The presence of a shrinkable clay sub-soil immediately around/under the cottage would need to be confirmed by trial hole excavations.

Cracking between the principal range and the outshut most probably reflects differential movement between the principal range and the outshut [Photo 12], which may be the result of a combination of footings, where present, of different depths and/or the presence of a shrinkable clay sub-soil.

Although the cracking is not considered to be indicative of significant structural movement it is anticipated that it will be subject to continued seasonal movement. The extent and nature of the movement needs to be determine through monitoring over at least a full season [one year].

Oxley Conservation Ltd 4 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

4.3.2 Front elevation

The front [east] elevation suffers from bulging and cracking that does not appear to be associated with ground related movement [Photos 13 & 14]. The causes of the movement to this elevation appear to be related to inherently poor structural detailing, which it is expected to include the:

o Lack of adequate lintels to the ground floor window openings; o Decay to concealed timbers, such as bonding timbers and/or lintels; o Lack of adequate lateral restraint between the front and rear elevations of the principal range.

4.3.3 Further investigation

The recommended further investigations [5.1], to confirm the constructional detailing and condition of concealed timbers, would be highly disruptive to the occupant[s] of the building, consequently it may be preferable to defer these works until the building becomes vacant.

If the building remains occupied for more than the next 18–24 months, subject to the findings of the continued monitoring of the movement [5.2], it is recommended that the further investigations be carried out within this time- frame.

4.4 Damp

The base of the external walls appear particularly damp [Photo 17], where readings were taken internally with a moisture meter the exposed [rather than lined] walls were noted to be damp. Timbers in contact with damp walls will be at increased risk of active decay.

The effectiveness of the discharge of rain, and surface, water away from the building needs to be confirmed and improvements made as found necessary so that a potential primary cause of damp to the cottage can be eliminated.

The careful removal of cement pointing and raking out of weathered pointing and the repointing of the walls with an appropriate lime-based mortar would improve the ability of water to evaporate from the walls [Appendix 3].

4.5 Tile hangings

The tile hangings to the first floor of the south gable are in need of extensive repair/replacement and would also benefit from some improved detailing [Photo 16].

The need for repair provides the opportunity to improve the thermal performance of the first floor wall to the south facing gable, which is only a single brick [4 inch] thick.

Oxley Conservation Ltd 5 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

5 RECOMMENDATIONS FOR REPAIR

Budget Ref No. Repair/Recommendation Item Category of Task Cost Estimate GN GENERAL NOTE

Provisional allowances have been made for budgeting purposes; the costs will, in many cases, be informed by the results of the further investigations.

FI FURTHER INVESTIGATIONS Carry out investigations behind the lining to the internal face of the front [east] elevation at ground and first floor level and at ground level to the left and right-hand flank [south and north] elevations; to determine the constructional detailing of the wall, the presence and condition of timbers [lintels, bonding and/or fixing timbers], the levels of damp and any indicators to inform the assessment of structural movement. 5.1 INVESTIGATION 750 These investigations will be disruptive and may be best left until the property becomes vacated. It is recommended that the investigations be carried out within the next 18-24 months. If it becomes apparent that the building will remain occupied for a period greater than 18-24 months it is recommended that the investigations be programmed to be implemented as soon as practicably possible. Initiate monitoring of the structural movement to the building, in particular to the front elevation and between the main building and the rear [west] outshut. The easiest method is to monitor the movement using tell-tales [suggested locations are shown in Photos 12 & 14] or, in the longer-term, raking out open and/or cement pointed joints with lime mortar [this would improve the weathering properties of the pointing during the monitoring period]. 5.2 INVESTIGATION 1,000 Internally, the building has been recently decorated and some cracks have been filled and/or painted over, for example between the first floor partition and front/rear walls. There is no evidence of opening-up of the decorated areas and, as such, the movement does not appear to be progressive. However, it would be prudent to monitor the decorated cracks for signs of further movement over the next year or so to determine the level of any movement. Investigate ground conditions and where rainwater is discharged to [soakaways?], and the effectiveness of the methods of 5.3 disposal. This will provide information upon which improvements can be made to the management of ground and surface INVESTIGATION 500 water and the discharge of collected rainwater. 5.4 Commission bat surveys to allow the roof and south elevation tile hanging to be programmed. INVESTIGATION 750 5.5 Report on the need to improve number of electrical power points within the cottage to reduce the risk of over-loading etc. INVESTIGATION 250 Check rainwater goods are sound and watertight during rainfall and implement adjustment and/or repair as found necessary; 5.6 INVESTIGATION 250 with particular attention to possible leak to the rear [west] gutter. Carry out trial investigations to determine the ease with which cement-based pointing can be removed without damaging the 5.7 INVESTIGATION 250 brickwork.

Oxley Conservation Ltd 6 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

Budget Ref No. Repair/Recommendation Item Category of Task Cost Estimate A URGENT WORKS 5.8 Implement repairs and/or adjustment to address any defects identified to the rainwater goods. STC 250 BACKLOG/ 5.9 Implement recommended improvements to the electrical system and how it is used. 750 IMPROVEMENT B WITHIN 18 MONTHS Strip and recover the roof slopes to the cottage taking the opportunity to improve the weathering/flashing detailing with the BACKLOG/ 5.10 chimney stacks, to repair/repoint the chimney stacks and to install well-detailed insulation, in particular above the rear [west] 17,500 IMPROVEMENT outshut. 5.11 Assess fully exposed roof timbers and implement repairs as found necessary; anticipated as being minimal. BACKLOG 500 5.12 Adjust and improve the detailing of the insulation within the roof space when the roof is stripped and recovered. IMPROVEMENT 250 Strip the tile hangings to the south [left-hand flank] elevation repair the exposed wall as necessary, take the opportunity to add BACKLOG/ 5.13 7,500 thermal insulation to a single skin [4 inch] wall, re-clad with new tile hangings. IMPROVEMENT When providing the insulation to the south elevation ensure that the problems of condensation are reduced by reviewing the 5.14 detailing of the insulation to a 4 inch single skin wall, an adjoining 9 inch wall and internal wall linings by removing cold- IMPROVEMENT INCL bridges. Strip and recover the roof slopes to the front porch taking the opportunity to improve the weathering/flashing detailing with 5.15 BACKLOG 1,500 the front elevation. 5.16 Implement improvements to the management of ground and surface water and the discharge of collected rainwater. IMPROVEMENT 2,500 5.17 Implement repair/replacement of the internal panelling [based on minimal disturbance]. BACKLOG 2,000 5.18 Repair timbers found to have suffered from decay. BACKLOG 500 BACKLOG/ 5.19 Carefully remove cement pointing and repoint with appropriate lime-based mortars. 2,500 IMPROVEMENT It is anticipated that the repair and decoration of the external joinery will have been completed and, as such, are not included 5.20 N/A N/A within the recommended repairs. C WITHIN 5 YEARS BACKLOG/ 5.21 Carefully remove cement pointing and repoint with appropriate lime-based mortars. 3,000 IMPROVEMENT

Oxley Conservation Ltd 7 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

6 BUDGET COST ESTIMATES

6.1 Basis of Estimates

The estimates included within the report [5. Recommendations for Repair] are based on the visual non-destructive inspections made for the production of this Report. No further investigations or opening-up has been carried out.

The figures presented in this Report are prepared on a budget estimate basis, derived by lump sum allowances as quantification is impracticable from the information available.

6.2 Assumptions

The following general assumptions have been made:

o The cost estimate applies only to the repair of the building and associated fabric. o The budget costing is based on the assumption that ‘like-for-like’ repairs will be adopted so that the appearance, character and performance of the building can be maintained; o Works specified to a ‘conservation’ standard, including traditional and appropriate materials and methods of repair; o Works to be competitively tendered; o No allowance for inflation from current prices has been made; o Works to be performed by a contractor experienced in working with historic buildings; o Reasonable access will be available to the site and the contractor will not be restricted in working a ‘normal’ working week.

6.3 Caveats

To achieve accurate estimates of what it would cost to carry out the works itemised a detailed specification and schedule of repair will need to be produced and issued to tender for specialist building contractors to competitively price. The following have been excluded from the estimates provided:

o Services [electrics, water, plumbing, drainage, hot water and heating etc.]. o The fitting out of bathrooms and kitchens. o Inflationary costs beyond the date of the estimate [March 2017]. o VAT. o Professional fees.

No costs have been included within this Report for implementing the recommendations of an asbestos survey or the need to respond to the presence of asbestos.

It is important to appreciate that until the scope and the programming of works is confirmed it is not possible to provide a conclusive cost estimate.

All repair works to older buildings, and in particular older buildings, involve a degree of uncertainty with respect to the amount of work that may become apparent as elements of the building are opened up.

Oxley Conservation Ltd 8 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

7 WILDLIFE

The inspection did not identify whether or not the building was actively used as a habitat by wildlife. It is particularly important that the presence of protected species, such as bats is determined so that where they are present the future repair works can be planned and programmed accordingly.

If it is found that bats use the building, for example for hibernation, their presence will need to be taken into account within the works to the roofs and within the roof spaces, such as the timing and detailing of any repairs and the installation of roofing felt and/or insulation.

All the buildings, trees and other potential habitats that could be affected by proposed works need to be included within future surveys.

Bats are a protected species. Under The Wildlife and Countryside Act 1981 [as amended) and The Conservation [Natural Habitats & c.] Regulations 1994 [as amended].

Prior to programming and initiating any works that may disturb bats, or disturb, damage or destroy their habitat, it is essential that the proposed works are designed with the input of an ecologist and that, where necessary, a licence is obtained and/or mitigation strategies are in place prior to works commencing.

8 LIMITATIONS

The inspection was carried out in accordance with the Conditions of Engagement. It is a strict condition of the agreement that the work undertaken is on behalf of the named client only and their professional advisors and that the Report shall not be shown to any other person(s) without the written consent of Oxley Conservation.

All statements and expressions of opinion contained in the Report are provided on the strict understanding that they are for the benefit of the named client(s) and their professional advisors only. Oxley Conservation accepts no liability in contract or tort to any person other than the client.

I trust that this Report provides sufficient information and advice to act as a positive step towards the repair and continued preservation of Yew Tree Cottage.

If you require any further information or assistance with regard developing this Report please do not hesitate to contact me.

Richard Oxley BSc DipBldgCons MRICS IHBC RICS Accredited in Building Conservation 31st March 2017

Oxley Conservation Ltd 9 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

8 SELECTED PHOTOGRAPHS

Photo 1 [left]: Front [east] elevation

Photo 2 [right]: Rear [west] elevation

Photo 3 [left]: Tile hung first floor of the south gable and outshut

Photo 4 [right]: North gable and lean-to outbuilding

Oxley Conservation Ltd 10 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

Photo 5: View within roof space showing softwood [larch] pole rafter roof frame.

Photo 6 [left]: Detail of underside of the outshut roof; showing no roofing felt or insulation is present.

Photo 7 [right]: Area of insulation lifted to reveal elm ceiling joists and lath and plaster ceilings [may not be present to other areas].

Oxley Conservation Ltd 11 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

Photo 8 [left]: Detail of the west catslide roof slope; note weathered and damaged tiles.

Photo 9 [right]: Underside of roof slope visible in the roof space. Note lack of roofing felt, damaged/spalled tiles and corroded nail fixings/hangings. The roof will need increased levels of repair to keep the roof coverings in a sound and watertight condition.

Photo 10 [left]: The south chimney with a lean towards the prevailing elements [south].

Photo 11 [right]: Detail of the north stack; note the cracked and loose cement mortar fillet.

Oxley Conservation Ltd 12 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

Photo 12 [left]: Detail of the junction between the north of the principal range and outshut reflecting a building line and/or differential movement.

Photo 13 [right]: Detail of front elevation showing the distortion and bulging around and above the north ground floor window.

Photo 14: Detail of front elevation; note the stepped cracking above the window, this brickwork is also bulging.

Oxley Conservation Ltd 13 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

Photo 15: Detail of the south elevation. The visible ground floor brickwork to this elevation appears to be contemporary; which is indicative of the principal range and outshut being constructed at the same time.

Photo 16: Detail of poor condition and detailing to the tile hanging to the south elevation.

Photo 17: Typical example of damp brickwork near ground level.

Oxley Conservation Ltd 14 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

APPENDICES

Appendix 1: List Description

YEW TREE COTTAGE

List Entry Summary

This building is listed under the Planning (Listed Buildings and Conservation Areas) Act 1990 as amended for its special architectural or historic interest.

Name: YEW TREE COTTAGE

List entry Number: 1237721

Location

YEW TREE COTTAGE, ANDOVER ROAD

The building may lie within the boundary of more than one authority.

County: Hampshire

District: Basingstoke and Deane

District Type: District Authority

Parish: Highclere

Grade: II

This record has been generated from an "old county number" (OCN) scheduling record. As these are some of our oldest designation records they do not have all the information held electronically that our modernised records contain. Therefore, the original date of scheduling is not available electronically. The date of scheduling may be noted in our paper records, please contact us for further information.

Date first listed: 06-Aug-1991

Legacy System Information

The contents of this record have been generated from a legacy data system.

Legacy System: LBS

UID: 138323

List entry Description

Summary of Building

Legacy Record - This information may be included in the List Entry Details.

Oxley Conservation Ltd 15 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

Details

SU 46 SW HIGHCLERE ANDOVER ROAD (south west side) 1/11 Washwater

Yew Tree Cottage

II

House. Early C19. (Brick dated 1811 or 1814) with some later alterations. Red brick with blue brick headers in Flemish bond, blue brick secondary arches and platt band to front elevation. Plain tile roof; brick end stacks with terracotta pots. 2 storeys; 2 bays, with rear outshut under catslide roof. Central entrance has door of 6 moulded panels with roll-moulded wooden surround and header-brick flat arch; C20 gabled porch. 3-light metal windows, outer lights leaded, central lights casements with vertical glazing bars and original hooks and catches. Ground-floor windows with segmental header- brick arches and scrolled keystones; 1st floor windows with flat heads and fire insurance plaque between. Brick above door dated and with initials 'E+C'; 2 other bricks initialled 'F+B' and 'M+W'. C20 vertically- boarded outshut on right. Rear; 2 windows, as at front but of 2 lights; small,leaded light below eaves on right. Right return; 1-light window with vertical glazing bars to outshut gable. Left return; 1st floor tile hung, with small windows on left. Interior not inspected.

Selected Sources Legacy Record - This information may be included in the List Entry Details

National Grid Reference: SU 44858 62763

Map

Oxley Conservation Ltd 16 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

Appendix 2: Implications of listed status

The following is a brief introductory summary of the basic implications of the listed status of the building.

Consent is normally required for demolition, in whole or in part, and for any works of alteration or extension which would affect its character as a building of special architectural or historic interest. It is a criminal offence to carry out such works without consent, which should be sought from the local planning authority. It is therefore essential that any work that affects the character of the building be only carried out after listed building consent has been obtained from the local planning authority.

Listed building controls apply to works, both externally and internally, that would affect a building's special interest, whether or not the particular feature concerned is specifically mentioned in the list description. This effectively means the whole of the building is listed, including any modern extensions and internal features that form an essential part of the character of the building.

The local planning authority have the right [or Historic England where the owner is a planning authority], without any time limit, to prosecute or issue a listed building enforcement notice, in respect of any unauthorised works carried out to the building. An enforcement notice can require the building to be brought back to its former state, or if that is not reasonably practicable or desirable, require other works specified to alleviate the effects of the unauthorised works. Listed building consent can be obtained for the works, if it is considered that consent would have been granted for the works. If consent is granted, it is not retrospective, the works will only be authorised from the date of consent.

Local authorities [or Historic England where the owner is a planning authority] have the powers to take action where a historic building has deteriorated to the extent that its preservation may be at risk. These powers include repairs notices. If the local authority considers that a listed building is not being properly preserved, it may serve a repairs notice on the owner. Local authorities usually consider the use of repairs notices where protracted failure by an owner to keep a listed building in reasonable repair places the building at risk. This illustrates that there is an implied onus on the owner of the building to keep a listed building regularly maintained and repaired. It is therefore in the best interest of both the building and the owner to carry out repair and maintenance that keeps the building in reasonable repair.

It is generally accepted that the regular maintenance and repair are the key to the preservation of historic building. Modest expenditure on repairs can keep a building weather-tight, and routine maintenance can prevent much more expensive work becoming necessary at a later date.

If you intend to repair, maintain and/or alter the property it is essential to ensure that you are not going to implement works that will affect the special architectural or historic interest of the building. It is therefore imperative that you discuss any proposals that you may have with the local authority conservation officer and/or seek independent specialist professional advice before implementing any alterations or works.

Oxley Conservation Ltd 17 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

Appendix 3: The traditional performance of old buildings

Introduction

This appendix is a brief introduction providing a basic definition of what the traditional performance is for old buildings, in particular the fabric, and outlines the consequences of any changes to that performance. In light of the use of impermeable materials (such as cement-based renders, mortars and plasters and modern paints) to modernise and repair the building it is important to appreciate how old buildings traditionally performed, and how changes to the traditional performance can have a detrimental effect upon the condition of older buildings.

The ‘breathing’ building

In general, the materials used in the construction and the traditional repair and maintenance of old buildings allowed moisture to enter and escape from the fabric by the process of evaporation. The building performed as a ‘breathing’ structure.

Traditional materials

Traditionally older buildings were constructed and repaired using soft and permeable materials, such as lime and/or earth based mortars, renders, plasters and limewash (refer to Appendix 4). These materials allowed the building to ‘breathe’ (refer to the illustration below).

The removal & replacement of traditional materials

Repairs have been carried out during the building’s recent history using modern paints and cement based materials. These have replaced or been applied over traditional finishes and have changed the manner in which the building performs.

The consequences of changes in the traditional performance

The use of impervious materials can alter the traditional performance of a building from a ‘breathing’ structure to one that puts a greater reliance upon preventing water/moisture from entering the structure.

Where impervious materials are used and moisture enters the fabric there will be an increased risk of moisture becoming trapped and/or displaced by impervious materials.

It is important to appreciate that where moisture becomes trapped in the construction and the fabric is subjected to prolonged dampness there is an increased risk of timber decay.

Oxley Conservation Ltd 18 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

Diagram taken from The Control of Damp in Old Buildings, Technical Pamphlet 8, The Society for the Protection of Ancient Buildings (SPAB).

Diagram illustrating the traditional ‘breathing’ performance Summary of the traditional performance

To summarise, the use of impervious materials is contributing to problems of damp at the subject property. It is therefore imperative that as much of the ‘breathing’ performance is reinstated, primarily by removing the impervious materials and that materials compatible with the traditional ‘breathing’ performance of the building are used in future programmes of repair and maintenance.

Materials that are impervious are generally incompatible with the traditional ‘breathing’ performance as they impair the evaporation of moisture. For this reason the use of impervious materials, such as cement mortars, plasters and modern paints, should be avoided wherever possible in the future repair and maintenance of the building.

Oxley Conservation Ltd 19 of 20 April 2017 Survey Report Yew Tree Cottage, Wash Water, Berkshire

Appendix 4: The qualities of lime based materials

This is brief introduction to the qualities, and limitations, of lime based materials. The majority of lime-based materials are soft, porous and flexible. This is advantageous to traditional buildings because the materials will be compatible and consistent with the original fabric. The main qualities of these materials are that they allow for movement within the building and, most importantly, allow the building to ‘breathe’. The permeability of lime- based materials reduces the amount of moisture that can become trapped within the building fabric as moisture is allowed to evaporate. Thereby alleviating the problems associated with dampness, condensation and associated timber defects.

Modern cement based renders, pointing and plasters usually have a hard finish and are impervious to moisture. Modern finishes, due to their hardness, are prone to cracking. Any moisture that has been drawn through even the finest of cracks will become trapped behind a hard impermeable modern finish, as the moisture is unable to evaporate. This combination of hard and impermeable finishes can exacerbate any problems of dampness and/or timber defects within a building. The provision of modern masonry paints to either lime or cement finishes will also trap moisture within the construction, thereby compounding any problems suffered by the building.

Many modern materials and finishes claim or are perceived to be 'maintenance free'. This may apply to a certain extent to the material itself, but not to the remaining historic fabric. The historic fabric can suffer from the consequences of moisture being trapped within the construction as a result of the introduction of a 'maintenance free' product. it should be appreciated that remedying the consequences of applying modern materials to traditional buildings can actually be more expensive then carrying out regular and routine maintenance programmes.

Traditional materials require regular maintenance. The old adage 'to do a little, and often’ sums up the basic needs and requirements of lime based materials. The need for regular maintenance may seem to be expensive, but will in fact reduce the problems that would otherwise be suffered in the long-term. This makes regular maintenance effective in terms of cost and in the performance of the building.

Lime plasters are naturally ‘soft’ and are therefore prone to mechanical and abrasive wear and tear. The porous nature of lime plasters and washes means that they do not provide a uniform finish. The appearance and colour of the lime finishes will actually change with the weather and will also reflect the levels of dampness/moisture content within the underlying fabric. This can make the building visually interesting and attractive; it will also assist in identifying areas that are prone to continued dampness, enabling targeted investigation to be implemented to the areas of concern.

This is a brief introductory note on the qualities and limitations of the lime based materials that are recommended for use at the subject building. The use of these materials will assist in improving the general performance of the building and will also complement and enhance the visual presentation of the building.

Oxley Conservation Ltd 20 of 20 April 2017