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The ins and outs of thatch
Thatch as a building material is an age-old practise and yet , even with the advent of newer technologies and materials , it is still relatively popular . We take a look at the pros and cons of using thatch , its history and why it ' s so popular , and innovations made in this area over the years .
By Kelly-Ann Prinsloo
Good quality straw thatch can last for more than 50 years when applied by a skilled thatcher . Image : Pixabay
WHAT IS THATCH ?
Although thatch is popular in Germany , the Netherlands , Denmark , parts of France , Sicily , Belgium and Ireland , there are more thatched roofs in the United Kingdom than in any other European country .
Good quality straw thatch can last for more than 50 years when applied by a skilled thatcher . Traditionally , a new layer of straw was simply applied over the weathered surface , and this spar coating tradition has created accumulations of thatch over 2.1m thick on very old buildings . The straw is bundled into yelms before it is taken up to the roof and then is attached using staples , known as spars , made from twisted hazel sticks .
More than 250 roofs in southern England have base coats of thatch that were applied over 500 years ago , providing direct evidence of the types of materials that were used for thatching in the medieval period . Many of these roofs are thatched with wheat , rye or a maslin mixture of both . Medieval wheat grew to almost 1.8m tall in very poor soils and produced durable straw for the roof and grain for baking bread .
Technological change in the farming industry significantly affected the popularity of thatching . The availability of good quality thatching straw declined in England after the introduction of the combine harvester in the late 1930s and 1940s , and the release of shortstemmed wheat varieties . Increasing use of nitrogen fertiliser in the 1960 to 1970s also weakened straw and reduced its longevity . Since the 1980s , however , there has been a big increase in straw quality as specialist growers have returned to growing older , tall-stemmed , ‘ heritage ’ varieties of wheat such as Squareheads Master ( 1880 ), N59 ( 1959 ), Rampton Rivet ( 1937 ), Victor ( 1910 ) and April Bearded ( early 1800s ) in low input or organic conditions .
Weathered reed is usually stripped and replaced by a new layer . It takes four to five acres of well-managed reed bed to produce enough reed to thatch an average house , and large reed beds have been uncommon in most of England since the Anglo-Saxon period . Over 80 % of the water reed used in the UK is now imported from Turkey , Eastern Europe , China and South Africa . Though water reed might last for 50 years or more on a steep roof in a dry climate , modern imported water reed on an average roof in England does not last any longer than good quality wheat straw . The lifespan of a thatched roof also depends on the skill of the thatcher , but other factors must be considered – such as climate , quality of materials and the roof pitch .
In areas where palms are abundant , palm leaves are used to thatch walls and roofs . Many species of palm trees are called ‘ thatch palm ’, or have ‘ thatch ’ as part of their common names . In the south-eastern United States , Native and pioneer houses were often constructed of palmettoleaf thatch . The chickees of the Seminole and Miccosukee are still thatched with palmetto leaves .
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