Thatch stripping raises the question of how far you strip when stripping.
When stripping an old roof down to a base coat, does the thatcher strip out 100% of the edges of the roof – the eaves and gables – or does he strip just the last layer or layers and leave the first layer in place? An old property may have any number of layers which have built up the thickness of thatch over many years, but it is unusual to find more than 2-3 thatch layers at the eaves.
Not stripping out the eaves means less waste to get rid of, there is no danger of the property leaking in water if the work is left un-sheeted and with many old roofs it avoids having to put in some additional timbers to fix the thatch to if the existing ones are in a poor condition.
However if the thatcher thatches over the old eaves and gables, he is governed by their shape and levels, which can dictate the shape of the thatch higher up the roof – so he has less control over the finished shape of the thatch.
We generally will always strip out the edges completely as the roof will look smarter and after the thatching is finished no body will be any the wiser that there is still the old thatch under the new thatch.
By starting a new, a uniform pitch up the roof can be achieved.
I suppose an analogy is when people wallpaper over the old paper – it never quite looks as good around the skirting boards…