This is what we call a cricket... It's a ridge structure designed to divert water on a roof around the high side of a chimney. Unfortunately, for this homeowner the previous roofing did not install one, hence the damaged wood picture below (left side). New Look is happy to help our customers avoid future damage due to improper installation. We love doing it the right way!

For any questions or comments, please feel free to email us at jwest@newlookroofs.com, we hope you have a great day and thanks for reading! 

- Julian