Can you say leak? Such a low pitch will not shed water fast enough and you will get water under the shingles. If you want the shingles, you will have to first cover the roof with a self sealing membrane (ice and water shield) which will provide an effective water barrier beneath the shingles. What is on the roof now (typical trailer metal)? Be sure you have enough substrate for nailing to.The roof on this trailer is a 1 pitch, it doesn't get that much wind on it where its located. I know shingling a roof on such a low pitch voids the warranty but how many more issues should I worry about.