Have a leak in a seam, a rip or a tear in the roof or side of your trailer? I did. I had a dent in the roof of my trailer that is right on a seam. It allowed water to pool, and eventually leak. The best fix I found was 10’x6″ white sealing patch tape (Di-seal I think). The white tape was the closest match to the color of my trailer. What I did was apply the tape the entire length of the seam to make sure it was completely sealed. You need to Clean the area well. Make sure it is dry and free of debris. Apply the tape on a warm day it makes the adhesive stick better, and makes the tape more pliable. My trailer is aluminum with ridges, and the tape adhered well. I put the tape on two year’s ago and the leak is still sealed. You can see in the picture it goes completely across the width of the trailer.