There i was up in the loft attempting to cap off a water pipe with a fitting that appeared to be slightly to small when it occurred to me that maybe my pipes are so old they are pre metric. Now i know the metric is just imperial in millimeters, but thats not an exact equivalent. Maybe my pipes are that old!... anyway this all leads to thinking of foreign pipes. Are say french pipes totaly metric and always have been? are they then different sizes? And are American pipes another size again? (maybe bigger?).... anyone know?