A thatch comeback?
Perfectly intact thatch roof with wood ridge cribbing - near Klintholm Havn, Denmark. Photo by Tracey Mactavish.
On a recent trip through Denmark I was enthralled by the volume of existing houses and farm buildings that maintained thatch roofs in very good condition. Particularly interesting was the different types of roof ridges in the different regions of the country, some with wood cribbing as shown in this photo of a home near Klintholm Havn and some with straw tops in northern Jutland. (I missed visiting the eelgrass roofs of the island of Laeso - only meeting up with local eelgrass nerd @abb_brown after arriving home from our trip!).
I grew up on a farm surrounded by a lot of straw – so it is fascinating to learn how the Danes used this resource as a durable protector for their homes and livestock buildings. Denmark’s climate is very similar to ours so it makes me think of the potential for modern thatch in Canada. As a by-product of agriculture this is an untapped asset. The material is natural, sequesters carbon, and can last for up to 50 years or more with maintenance, far exceeding the lifespan of any modern roofing material.
The Wadden Sea Centre by Dorte Mandrup in Denmark has created a bit of a cult following of modern architects, admiring the sculptural quality and seamless transition of wall to roof that can be achieved with this material and technique.
Other sophisticated applications include Architype’s UEA Enterprise Centre which features a thatch cassette panel system around the upper faces of the building, while LEVS Architecten’s Kaleidoskoop project utilized the first thatch panel system certified for fire risk when completed in the Netherlands in 2012.
The most obvious hurdle for Canadian application is the availability of skilled tradespeople. Do you know any master thatchers? Not a common business card in this country….
In what other formats could straw be utilized? Learn more about straw building material testing and products from the Parsons Healthy Materials Lab. We will chat more about agricultural by-products and food waste and their potential as building material in the near future!