I have a small leak in the roof over my porch. It seems as if a shingle has cracked and I have determined that is causing the leak. Is there a permanent type of roof cement that will work even on a damp surface? Anyone have any recommendations on standing seam metal roofs? Recommended brands? I have heard about the Royal York Roofing Ltd services ( royalyorkroofing.ca/ ) but I am a bit confused which to use. Do you guys have any recommendations or suggestions? please share your ideas.