If you are a thatch house owner you may have had various lifespans for materials told to you. They normally state that water reed will last 50-60 years and combed wheat straw will last 30-35 years. This can occasionally be the case, however with the rise in climate change and more vehicle emissions these old timescales need revising.
Rarely do I see a water reed roof go past 40 years or a straw roof go past 25.
One way to make sure you get the maximum lifespan from your roof is to maintain it. All to often I see thatch roofs that may have survived 10 or 20 years longer, if only there had been a regular maintenance plan in place. This could just involve the removal of moss build up at an early stage, or a small patch to keep an even water flow from the roof.
I recommend having a roof check every 2 years, we can spot things before they become a major issue and put it right, making sure you get the most out of your thatch.
Think of it like a car. A car will last you 20 years, but you will need many services for it to last that long.