Thatch is a historic roofing material still seen in some reconstructions and homes designed for a traditional appearance. Thatch roof utilizes bundles of tightly packed long-stem plant material as the roof sheathing. The roof not only sheds water but also serves as insulation for the building. As with all traditional building methods, there are materials that have been used for centuries. Modern builders use some of the same materials in this era.
Wheat Reed - Wheat reed is a commercially grown farm crop in parts of England. The wheat is harvested in bundles using a binder. The grain is threshed from the stalks before the thatch is bundled for use as roofing, which makes the wheat reed a byproduct of the grain harvest process. However, the process requires a lot of manual labor and results in a thatch that has a useful life of 25 years.
Water Reed - Water reed is among the most commonly used thatch materials and is found across Europe and North America. The plant grows in wetlands and is an invasive species in some areas where it grows in an uncontrolled manner. Cut the water reed after the plant has gone dormant to reduce the shrinkage associated with green plants. An acre or water reed yields about 400 bundles, which will cover about 400 square feet of roof area. A water reed thatch roof should last about 40 years.
Water Grass - Water grass, sometimes known as sedge, is used on the ridges of homes thatched with water reeds. Water grass is commonly harvested in the fall of the year. Sedge is also used as a livestock feed and in bank or ditch stabilization.
Thatch Disadvantages - Thatch roofs look traditional and last as long or longer than most other roofing materials. Homeowners with thatched roofs pay more for fire insurance than other roof types. Other disadvantages include the possibilities of bird or rodent infestations. Property owners should also check local zoning and building code regulations before starting a thatch roof project.