The contractor I contacted usually installs Gerard stone coated metal roof with hidden valley. He said hideen valley does not have problems like ice buildup in hidden valley in our climate ( Northwest USA ). We do have a few very cold days. I am concerned with ice in hidden valley. But open valley can collect debris, causing water dam. Although in theory, I can see these debris dams and clean them with open valley, but it is not always practical to get up there to do the cleaning. It seems that hidden valley collects debris on top of shakes, but water still can filter through to get to the hidden valley so that water damming will never be a problem ( water can always flow ). What are the advantages and disadvantages of open vs. hidden valley?
Guest User
2004-08-09 02:29:58.000000
Different people refer to these valley designs differently.
To me, an "open" valley is one which does not have the panels being received into a J or other channel. In other words, as water, etc. comes down the roof, it stays on top of the roofing and the valley pan and does not run down in hidden channels.
A "closed" valley, on the other hand, carries water in concealed channels beneath the roofing.
In my experience, according to my definitions above, "open" valley is far better because it will not clog and then overflow.
