Ashphalt shingle roof leaks?

I guess you could call Mike Holmes, but in the meantime lets get back to basics. Your shingle roof is leaking from the outside, because the flashing (thats the lead strip that is fixed to the original wall to cover the join between old and new) may have a gap to let water in. Ideally there should be a groove cut into the original wall, and the lead flashing pushed in. The lead is then bent downwards so that it completely covers the join from the new roof to the old wall, and water is cast off. Tar paper is the stuff thats fixed on top of the new rafters, before the asphalt shingles are fixed on - sort of an additional water barrier. Wooden shingles are normally only used in the vertical position, usually made from cedar or similar material. So, if I were you, I'd remove the fibreglass insulation from the ceiling of the new roof, and look for traces where the water is coming in. On the outside of the roof, there will be a fault on the flashing somewhere - if you can see a gap, then water certainly can. Good luck with your investigation! We British have much to thank you Canadians for past deeds but our governments seem to forget it. Cheers!

John
April 2008