Thatched buildings, while not specifically garden related, often inspire landscaping plans, especially plans for cottage-type layouts. Garden outbuildings may also have thatched roofs. The roofs are especially appropriate because they are made of natural materials, including wheat straw and water reed. Though thatched roofs are most often identified with buildings in the United Kingdom, however, various types of thatching have been used all over the world for thousands of years. Roofing thatch can be woven into distinctive, decorative patterns.
Thatchers use overlapping sheaves of dry wheat straw or other materials--usually sourced from the local area--to construct a roof. The roof is built from the lowest level up, with each successive sheaf of roofing material overlapped by the one that follows it. The sheaves are fastened to the rafters and woven together in various ways depending on the skill and preferred technique of the thatcher. Thatched roofs are usually pitched so that moisture slides off quickly rather than penetrating the thatch. A roof thatched with water reed can last 60 years, as long as it is maintained and repaired regularly. Thatch gradually thins as it ages and a very old roof may reveal the fastening materials. A new thatched roof can be laid directly on top of an older one.
In the United Kingdom, archaeologists have found post holes that provide evidence of the existence of thatched structures dating back to at least the Iron Age. In parts of Asia and Africa, thatched buildings similar in shape to those indicated by the U.K. post hole evidence are still in use. Thatch was traditionally used on the dwellings of the poor because the material was readily available at little or no cost. Some Native American tribes thatched their roofs, as did early colonists. In the U.K., thatch was the most widely used roofing material in Medieval times and was a roofing staple in the countryside until the mid-1900s. After that, changes in threshing procedures and increases in labor costs made it more expensive than more modern roofing materials.
Art of Thatching
Thatching is a skilled trade that has historically been passed from father to son and from master thatcher to apprentice. When thatching declined in the mid-20th century, English county-based groups of master thatchers banded together to form Master Thatcher Associations (1947). These associations united into the National Council of Master Thatchers Associations in 1987. There are also associations of thatchers in the Republic of Ireland, France, Denmark, the Netherlands and South Africa. In addition, there are professional thatchers who work in the United States.
Thatch roofs contain natural air pockets, making them good insulators. They are also environmentally friendly because they are made of natural, biodegradable materials. Though some homeowners finish off the ceilings of rooms that lie under thatched roofs, thatch is affixed directly to rafters, making a sub-roof unnecessary.
One of the reasons why thatched roofs fell out of favor was worry about the flammability of the roofing materials. For this reason, some thatched roofs are sprayed or coated with a fire-retardant chemical. Alternately, fire-retardant boards can be installed under the thatching.