Property Care Alternative Repair Strategies for Traditional Buildings, working with Society for the Protection of Ancient Buildings (SPAB)
The course was held at the PCA practical training center, which provides excellent facilities for hands on practical and theory courses to be held for both PCA and none PCA members, to get full hands on training in many aspects in the remedial industry.
The Society for the Protection of Ancient Buildings (SPAB) is Britain’s oldest building conservation charity, founded by William Morris in 1877, SPAB as approximately 8,500 members, membership starting from as little as £47.00 per year become a member here
This course provided further tuition for those working on traditional buildings, these are defined as solid-walled properties pre-dating about 1919, around 20% of the country’s housing stock.
Traditional buildings are constructed differently from modern properties which necessitates the use of different repair strategies. Many traditionally constructed buildings can be listed or located in conservation areas, which brings additional requirements to building works and regulations.
The course instructors being:_
Douglas Kent (SPAB Technical and Research Director)
Anthony Goode (Conservation builder and lime expert)
Dr Joe Bispham (Carpenter, joiner and historic building consultant)
Douglas Kent, speaking alternative repair strategies for traditional buildings, the topics covered within the course were :-
- Traditional buildings (1919), solid walls, lime-earth based mortar, shallow foundations.
- Vernacular architecture.
- Moisture control, damp diagnosis, comparing modern and traditional buildings and how they deal with dampness.
- Controlling dampness, using French drains, lowering ground levels, removing none permeable external paints and hard cement bridging renders to allow evaporation and drying of the structure. Careful use of lime plasters internally where there isn’t a salt problem.
- Structural flexibility.
- Thermal mass provided by the wall thickness, reducing the risk of condensation.
- Air tightness and the associated issues.
- Performance of the structures.
- Typical defects and types of repairs, typically timber framed properties.
- Listed building consent.
- Town and Country planning act 1947, 1990, justification needed for demolition works from 1968.
There are 500,000 listed buildings, throughout the UK, these are divided into, three different grades.
- 5% Grade 1 listed
- 5 % Grade 2 * listed
- The reminder being Grade 2 .
It is a miss-conception held by many, the listing applies to the external of the property, it applies to the entire building, inside and out, buildings can be de-listed subject to an appeal.
There are also, 15,000 Conservation areas throughout the UK, restrictions are not limited to buildings they can also apply to trees, gates, satellite dishes, dormers, article four being more strict with windows.
The history, manufacture and use of lime mortar/ Plaster was presented by Anthony Goode, this included the many types of lime materials available such as lime putty, hydraulic limes, and NHL, the limitations and advantages of lime when used on traditional constructed buildings.
Practical work shops were also undertaken to get a hands experience with the mixing and application of the various lime mixes, including hot lime, NHL as well as the finishing materials such as lime wash and earth based paints.
In the photographs above, Anthony Goode and Douglas Kent give a practical demonstration of the manufacture and the mixing of the various type of lime.
This also included a practical demonstration of the various stages of application of lime plaster on both hard and soft surfaces, such had laths which generally formed the stud walls and ceilings in a traditional constructed building, but these were also used to were plaster was applied over timber lintels or where dubbing out was required.
The presentation on timber repairs on traditional buildings was presented by Dr. Joe Bispham.(MSc. PhD. FIMMM)
The lectures covered the history of managed woodland from as far back as medieval times until the present day, the legal requirements for managing woodland, the timbers used and their location from local sourced timbers, as well as timbers which where imported, from as far back as the 18th century to the present day.
Various types of timber repairs, on traditional buildings, including many excellent case studies showing how repairs were carried out on properties using incorrect methods, resulting in structural and rot problems, the lectures also included information on where both modern and traditional methods of repair can be used sympathetically together, to both correct and improve past defects which had occurred
The importance of using timber with the correct moisture content to reduce swelling and shrinkage of timbers when installed into the structure. Generally the lower the moisture content the greater the strength, the accepted bench mark for timber decay being 20%mc.
The correct methods of working with timber and where to cut to prevent problems due to shrinkage and splitting when working with green oak, to get the best use of the timber both practically and economically.
The effects, disadvantages and advantages of the use of timber treatments with preservatives, varnishes, paints, water repellents, and how important the correct moisture content of the timber is when applying treatments .
Photographs showing the various section of timber, growth rings and sections of cut.
Photographs showing an historical section of a timber tenon from a timber framed house which was affected by fungal decay due to water ingress.
The course was very informative both from the theory and particle side, allowing interaction and discussion between both the traditional and the modern thinking contractors, to provide the best and most practical systems when working with each other and not against each other, what was obvious was we both wanted what was best for both the client and the building and we can learn from each other.
I would like to thank and congratulate and commend both SPAB and the PCA for coming together and providing this excellent course and I look forward to many more joint courses between the two organisations, to both help combine, use and expand the vast amount of knowledge and experience both parties can bring together, leading to the preservation of historical buildings and providing further learning and the passing on of knowledge of both traditional and modern systems and how these can be best combined to provide the preservation works and sympathetic repairs to properties, without damaging or destroying the properties and structures which form our historical heritage.