Hello Karl, and thanks for your helpful comments. The reason for the English larch was really just a cost decision – the project was over budget, and I had to find every saving I could whilst keeping the overall design intact. At the time, English larch was £28/m2, and Siberian larch £35/m2. Having said that, if I now include for treating the English larch, whilst the Siberian can be untreated, I doubt there’s much of a difference. Maybe I should give you a call about supplying the larch Karl? I seem to remember you can supply Siberian Larch.