I am going to replace the roof on my house built in 1936 and want a standing seam metal roof. I have read a lot about how if you are unlucky, the roof can become very bumpy. How can you ensure that it doesn't happen? The roof of the house has a slope of about 44 degrees. The base consists of rafters, felt, and tongue-and-groove boards, where parts may need to be replaced. The roof is 100 m2. Sending a picture of the house.