Never heard the name 'bitchamine' before, but just read about it in a book by Noah Boyd ('Agent X', 'The Bricklayer'). I've seen it demonstrated on 'This Old House' - recommended by good old Norm and Tommy, and I believe 'Home Time'. Works very well if applied before the first rows of shingles/shakes etc., on to the bare wooden roof to prevent ice dams from damaging the roof/causing leaks etc. The nails are sealed as soon as they puncture the membrane. In the book above it is described as 6 feet wide, but I thought that 3' would be sufficient, but of course depends on location I guess (heavy snow loads and melt/roof pitch etc.) Not sure that it would be any good to repair an already leaking roof - except of course if the roof is stripped and new shingles/shakes/tiles installed. Only recourse for above problem may be a new layer of shingles over the old ones, but this is merely a 'band aid' solution and not guaranteed to solve the problem.
Ed Wills, March 2011
