I took a look at a Thatched roof a few weeks ago that was up for sale. The owner had all but completed the sale when the prospective buyers instructed a Thatcher to give his opinion on the condition of the Thatch. The Thatcher said much of the roof was in a poor condition and needed urgently re-thatching. This news was passed on to the seller who was shocked because she believed the roof whilst needing some work was not too bad.
I visited the property and found that whilst the roof needed a new ridge and wire netting fitted to the coat work, it was in good order and would easily last the lifetime of the new ridge.
There is a logical reason why a thatched roof looks like it does and there are always indications as to how poor a roof is; these signs may be slippage, the fixings showing, the thatch looking thin, hollows and gulleys forming in the roof and damp penetrating at the back of the eave line etc. This roof had none of these and so I can only assume this other Thatcher needed the work!
We would always recommend that a prospective purchaser always obtains a written survey on the condition of a thatched roof and does not just rely on comments that a Thatcher or anyone else may make.