Well, had a good challenge yesterday with some old ivy that had literally become part of the Upvc window frames, even grown into the window seals, quite amazing just how bad this stuff sets in if left to do it's thing! The house was recently bought by a friend of mine who asked me if I could have a go at restoring them, think the last owner was a old chap who just left nature work it's magic as the place is in need of a mass of work inside and out, the worst windows were on the side of the garage and at the back. Spent about 90 minutes there yesterday and managed to get 3 windows and a door done, if anybody comes across this stuff, my method was to soak it all down with a strong UBIK solution and let it nearly soak in and dry, then just before it does soak it down with some water and a UPVC cleaner spray, then very gently blade the chucky bits off that started to sofen a bit and cut out the stuff in the seals as best as I could, then plenty of elbow grease with a sill cloth to get the rest off, then a scub with a medium/stiff brush and a final rinse with some hot pure. Buff up once nearly dry and think they came up quite good. Only took before pics of one window but they were all just as ming!