I am installing a Dura-Plus triple wall direct vent pipe. I am going thru the ceiling and am wondering about how to seal the flashing with my painted metal roof. This is the roofing that is about 36" wide and has 1" ridges in it about every 10". I know the flashing would not be a problem with a shingle roof, but the ridges of my metal roof have me scratching my head. I know I am supposed to cut my roofing and the flashing goes under roofing on the top and is supposed to lay on top of roofing on the bottom. Considering the flashing is flat and my roofing is ridged, is there an easy way to do this? Someone locally suggested I got a roll of "Peel and Stick" which is a sticky membrane on 1 side and aluminum on the other side. I was told to use that to seal all the way around it, but was just wondering if there is an easier or better way. Also, am I supposed to put a sideways split in my roofing near the bottom to allow the flashing to come from underneath and overlap roofing on the bottom? This is the flashing that is about a 30" x 30" square and has the large formed area with a storm collar that mounts over it.