Thatch – A Brief History
I became interested in building conservation in the 1980s due to an interest in thatched buildings. In the early 1990s I became more interested and involved with thatch and thatching. At the time there were significant differences of view about thatching and its future. At the time thatching had a seemingly good future because quite a number of new estates were being developed with thatched properties. The issue was whether to move to reed thatching because of its perceived longevity, and what to do about long straw thatching. The debate resulted in research sponsored by English Heritage and a guidance note being issued by English Heritage. The result of this work in the 1990s meant that all three thatch traditions have been maintained. However, thatch is once again under threat for various reasons. This article is not looking at the future, or how to overcome present problems, but looks at how we have arrived at this point.
There is evidence of thatch being used on buildings across the country for many centuries if not millennia. The term itself really refers to the use of any vegetation as a roof covering. Indeed, there are parts of the United Kingdom where non-standard vegetation is still used, including heather for example.
During the mediaeval period all but the most prestigious buildings were constructed from local materials. With many buildings this would have meant using vegetation grown locally, particularly in rural locations. As large parts of Britain were covered with crops for breadmaking etc., it followed that across most of the country thatched roofs were formed with rye, barley, or wheat. As crops changed so did the thatch and in more recent centuries wheat straw has become the most predominant material.
Because threshing methods resulted in damaged stems a form of thatching was developed that we now call long straw. As re-thatching involves stripping only to a sound base coat, it would not usually mean taking the thatch off back to the roof structure. As a result, some thatched buildings can have numerous layers of historic thatch, sometimes incorporating a variety of material. This results in a deeper ‘poured over’ style of thatch.
Smoke Blackened Thatch
With many mediaeval buildings there would have been no chimney, merely a hole in the roof. Therefore, any central fire in the hall or main roof would have resulted in smoke rising and blackening the underside of the roof. With many historic buildings we often see smoke blackened timbers. Of course, this also applies to thatched buildings. However, unlike tiled roofs (for example) with thatched buildings it is sometimes possible to also see smoke blackened battens and undersides of the base coat because over the centuries there has been no need to replace them.
With traditional straw thatching there was no need to completely strip a roof back to the frame, merely back to a sound base. This theoretically resulted in the base coat remaining in place for many centuries.
Even where the base coat has been stripped away, the battens often remained. In fact, it is more common to see smoke blackened battens than smoke blacked thatch.
Over the years, particularly where straw has been changed to reed, the base coats of these historic buildings have been stripped out and the smoke blackened thatch has been lost. Only a small number are known to remain, perhaps thirty to fifty and these are predominantly in the South and South West of the country. If you happen to have a thatched roof with smoke blackened thatch to the base coat then it is very rare and worthy of careful conservation. Discovering such would usually result in an uplift in the list grading.
There is also a long history of using reed from reed beds. This is mainly restricted to those areas where reed is grown in quantity such as the Norfolk Broads, Somerset Levels, etc. Some river estuaries would provide reed where there were managed reed beds around the country. However, reed was not common inland and the only time it was ever used any distance from source would be for estates where a rich landowner could afford to transport the material.
Whilst there is some evidence of reed having been used as linings to some thatched roofs (a ‘fleeking’ layer) it does not follow that reed was used for thatching in areas where reed beds were not present. In the past evidence of reed fleeking has been used to suggest that reed was more common across the country. This is not true. Normal village ponds and local rivers do not provide a sufficient amount of reed for complete thatching. However, such sources might have been sufficient to create reed fleeking coat linings underneath other forms of thatch.
Traditional methods of reaping and threshing meant that the straw used for thatching was often damaged and the method of thatching became what we now know as long straw thatching. Conversely, water reed was gathered in bundles held together by twine thus forming an undamaged material that required no significant site preparation for putting on the roof.
During the early years of the Industrial Revolution steam powered threshing and binding machines were developed and the resulting cereal crop stems were undamaged. The straw could be gathered in bundles much the same as with reed. Therefore, a method of thatching with straw was developed that was very similar to the method used for reed. This became known as combed wheat reed thatch. The areas that seemed to take on board this form of thatch quickest and developed it more than other areas were the Midlands, South and Southwest of the country rather than the East.
Reed thatching would often involve stripping back to the frame and is often a single coat material (unlike long straw). That said, in the Southwest there is a tradition of reed thatching on top of older coats, which does result in a thicker layer of thatch.
Combed Wheat Reed is often used over older coats, but can also be found as a single coat material.
Due to the nature of reed, it often results in an angular appearance, rather than the more rounded look of long straw. Also, block cut ridges were traditionally formed when using reed, because it is an easier way of finishing the ridge. However, as a block cut ridge is distinctive and considered aesthetically appealing, it has become common across all regions, even where flush ridges would be the historically correct style.
Thatch was still commonly used right through the 19th century and into the early 20th century. There are many villages, estate cottages, etc., that were thatched during this period. It was common and popular during the arts and crafts movement at the turn of the 20th century.
The improvement of transport, particularly rail, meant that mass housing estates could be roofed with slate and other materials that meant thatch did lose traction in many areas but the main factor that brought about the most significant decline were the wars of the early and mid-20th century.
What really change things was the First World War because many thatchers were killed and the decline of thatch occurred primarily in the interwar period. We then went through the Second World War, which resulted in further significant labour shortage.
Just after the Second World War the government of the day was looking at reviving craft industries, including thatching. When the government decided to start a thatch training scheme, they made a conscious decision to omit long straw thatching because it was more difficult and perceived as a short life material compared to water reed and combed wheat reed. The result of this was many thatchers being trained in water reed and combed wheat reed, but not in long straw. Those who maintained the long straw tradition tended to be those who did not necessarily require or follow the government training scheme. The tradition of long straw was maintained in East Anglia primarily. In many other regions that were traditionally long straw in character the change was primarily to combed wheat reed.
The amount of reed produced in the UK was insufficient to meet the increasing demand to thatch any significant number of properties. This was in part due to the limited reed beds, but also because these were reduced further due to RSPBA resisting attempts to re-open old thatch reed beds where there were nesting birds. Water reed really took off in the 1970s and 1980s but this was mainly due to importation of reed from abroad, primarily central and eastern Europe.
As an example of the changes, 50 years ago Dorset was an area where there would have been long straw and virtually nothing else (with some reed found only close to reed beds), but nowadays you will not find any long straw in Dorset.
Generally speaking, long straw is now only found in East Anglia; in most regions that that were once long straw the ubiquitous material now seems to be combed wheat reed and water reed; with water reed achieving increased popularity due to its perceived longevity.
The important thing to remember is that when dealing with a listed thatched building Historic England guidance will apply. In principle this means that the local tradition should be followed; if a property has been thatched in reed in recent decades, whereas previously it had been long straw, then when re-thatching the reversion to long straw would be required.
There has been much debate about this and in fact planning appeals and court cases. However, the important thing to realise is that when dealing with conservation we are looking to conserve and retain historic traditions including regional variations in thatch materials and styles.
With all thatch materials we have seen noticeable challenges in recent years. This is with regard to performance, but also supply and therefore the ability to re-thatch and undertake major thatching works in a reasonable timeframe. It does not help to see a number of fires to thatched properties that have hit newspaper headlines, thus causing potential owners to re-consider whether they want to live under thatch. These matters are being looked at by various bodies at present, but it would seem that climate change is a significant influence on the supply of material (all forms of thatch material). At the same time, the numbers of those wanting to go into thatching seem to be reducing.
The issues threatening the future of thatch are worthy of separate consideration and are not for this article. What I hope I have done is raise some awareness about the general history of thatch and how we have got to the present situation.
8th February 2023