I increasingly hear from thatch owners who have been misled about the lifespan of their thatch and the maintenance required within that lifespan.
Back in the 1980s, there was a building company who sold their new thatched houses and told the purchasers the roofs would last 40-50 years; what they did not tell these same people was that the roofs would need new ridges within this time frame. Several of the properties were purchased by retired people who got quite a shock a 12 years later when faced with a re-ridging quote of £3000-£4000!
I spoke to one of our customers recently who, when he bought his thatched property, was told by the previous owners that a water reed roof would last up to 90 years and within that time would need three ridges.
As a rule of thumb thatch owners should budget for a new ridge every 10-12 years, irrespective of whether the roof is thatched in straw or reed. There are very few roofs that will last more than 50 years. There is little agreement between thatchers as to how long Water Reed , Combed Wheat Reed and Long straw roofs should last and thatchers tend to cite examples of roofs which have lasted longer than expected as evidence that one cannot generalise.
I disagree; and with all things being equal in terms of quality of materials, workmanship, pitch of roof, aspect etc, a water reed roof should outlast a Combed Wheat Reed (CWR) straw roof, and a Long straw roof should not last as long as a CWR roof.
The problem is that with no substantive records of life spans of roofs, the misinformation and subjectivity, especially coming from well meaning people not in the trade will continue to confuse people. See our piece on life spans of thatch here)
These two photos show an old ridge, with a very poor pitch and a ridge we recently completed. The steeper the ridge the more likely it is to last as it will shed water better!