A roof thatched with water reed (a more durable and water-resistant material than straw) will last up to 70 years in the right climate. In Ireland reed roofs last on average 25 to 40 years. When a thatched roof needs to be replaced a new layer can be placed over the old. On old buildings up to four feet of thatch can accumulate.
A reed thatched roof is not easy to set alight as many people might imagine due to its steep pitch, and tightly packed surface. Public buildings are required to meet stringent fire specifications and reed thatched roofs can be made to comply with these.
The construction and material of a reed thatched roof make it no more prone to vermin than a conventional roof. Unlike straw there is no food value In Reed that would attract vermin.
The main body of the roof has a long life if properly maintained. A short maintenance programme (three to four days for an average cottage ) every eight to ten years will safeguard the durability and beauty of the average roof.
Over a foot of natural material ensures that a thatched building is cool in summer and warm in winter. today, as in the past thatch is the most energy efficient roof available.