Publications
Fire Precautions
"Every year, over 50 historic thatched buildings out of an estimated stock of 24,000 listed properties are destroyed and lost through preventable fires mysteriously breaking out in the thatch. The reason has been understood for a number of years, but still the losses remain constant."
Fire Precautions - Click to download the pdf file.
Designing out damage from fire. - Click to view “The Dorset Model”
A Practical Guide to Thatch and Thatching in the Twenty first Century
This recent NSMT publication was conceived with the express intention of providing a progressive report on the sustainability of thatching in a modern context. The intention is to follow on and build upon the five English Heritage Research Transactions on thatch, by capturing the knowledge and experience of working thatchers.
The Guide has been compiled as a response to the many questions raised by home owners regarding the sustainable maintenance of their thatched properties. A blend of traditional skills and modern craft demonstrates the innovation and limitations experienced in maintaining buildings of historical value in under present conditions.
The quality of thatch and thatching is probably the best it has ever been and expectations of performance are higher than at any time in the past. Paradoxically real quality has to be balanced with the demands of those in authority who are entrusted with the conservation of heritage, but do not always fully understand the long term impact of their requirements. To this end, it is important to draw a clear dividing line between the past and homes that may be listed, but which face all the demands that modern living can throw at them. Climatic, agronomic, legislative and economic changes are taking place at an unprecedented rate; these can no longer be ignored.
Copies of the guide (price £10.00) including UK post and packaging can be obtained from the NSMT office Telephone: 01844 281208 or e-mail marjoriesanders@btinternet.com.
Bats Beware!
"Many bats are endangered or threatened, so both UK and European legislation gives them very full protection. It is illegal to intentionally kill, injure or take any bat or to recklessly damage, destroy or block up their roosts or disturb them. Because bats tend to return to the same roosts each year, these sires are protected whether the bats are present or not."
Bats Beware! Click to download the pdf file.
Insulating properties of thatch
Question:
The current recommendation for insulation in a standard roof is 10.5 inches. I was wondering
if this is the same for a thatched roof or is less insulation required because of the thatch?
Answer:
From the most up to date information we have the U value of a roof refers to its thermal
conductivity, i.e. how quickly heat is lost from it, and is measured in watts per square metre per degree Kelvin.
The U value of 12 inches of water reed on a pitch of 45 degrees is about 0.35 W/sq m K. The current building regulations state that the U value required from a new roof is 0.25 W/sq m K. Therefore, on a new build, there would need to be some additional insulation under a twelve inch water reed thatched roof. However, thick thatch with multiple sparred layers will have a lower U-value. The U-value will also be affected by the roof space climate, for example, whether the roof space is well ventilated (draughty) or sealed, warm and snug.
Outside Halogen Security Lighting and thatch
Halogen security lights and internal spot lights can get very hot, very quickly. They are an acknowledge fire risk in conventional houses where they come into direct contact with drapes inside the house (the fire in Windsor Castle for example) or when fitted into poorly insulated recessed lights.
It is easy to take external security lights for granted, particularly in the summer months, but these lights when situated close to the eaves can also set fire to the thatch just from the heat that they generate.
New health and safety regulations, even for small scale maintenance jobs, are driving thatchers to adopt safe working practices to work only off scaffolding. This might be good for the thatchers well being but can lead to an accumulation of debris on the scaffolding close to security lights, which on rare occasions have been blamed for starting a fire, with devastating consequences.
The National Society of Master Thatchers advises all its members and their customers to be aware of the risks associated with the high heat generated by halogen security lights. They advise thatchers to examine the location of these lights and to actively take steps to isolate security lights before any work is undertaken on the thatch. Isolating security lights should be part of the risk assessment carried out for each job as part of compliance with the HSE safe working practices and from the thatchers point of view to demonstrate due diligence for the rare occasions when things do go wrong.
As a general safety precaution halogen security lights should be situated at least one metre from any overhanging thatch or from a thatched porch.
Planning and Thatch - Useful information and contacts
Planning (Listed Buildings and Conservation Areas) Act 1990, HMSO
Planning Policy Guidance Note 15: Planning and the Historic Environment, 1994, HMSO, ISBN 0-11-752944-3
Charles Mynors, Listed Buildings, Conservation Areas and Monuments, 4th Edition, 2006, Sweet and Maxwell
Design and Access Statements: Commission for Architecture and the Built Environment
www.cabe.org
Local Authority Thatch Policies and Guidance Notes
English Heritage: Thatch and Thatching Guidance Note 2000
English Heritage: Thatch and Thatching in England 1790-1940,
J. Moir & J.Letts, 1999
English Heritage: Smoke Blackened Thatch, John letts, 1999
www.English-Herit
English Heritage, National Monuments Record:
www.i
Tel 01793 414600
Local publications on thatch e.g. Devon Thatch, by Jo Cox and John Thorp
Society for the Protection of Ancient Buildings, Technical Pamphlet 8, Peter Brocket and Adela Wright, The Care and
Repair of Thatched Roofs
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NMST, Thatch Fires, Marjorie Sanders article in The Building Conservation Directory, 2006. http://www.buildingconservation.com/articles/allarticles.htm
The Thatchers’ Craft, Rural Development Commission, 1988