Question in the region of installing a composit roof? When you install a 50 year (composit shingles) roof, and you...

When you install a 50 year (composit shingles) roof, and you install metal valleys should the valley have opening on both sides to allow unrestricted run-off of water? Or can these valley be closed or covered with the shingles? I own been told two different answers by roofers and would approaching to know what the industry standard is. Please advise
Flooring for Foyer (foyer is bordered by 3...
Answers:    Your 50 year shingle alone will save water out if installed correctly, galvanize tin or aluminum valley is an added sanctuary. Cover it with the shingles, it will look so much better.