The valleys on a slate roof or tile roof are a lot different then those of a asphalt shingle roof system. On a shingle roof system you would run one side into and up the other side of the Valley. Then you would run the other side over top and cut the extra off leaving a strait cut all the way down the center of the Valley like the picture to the right demonstrates. Now some contractors weave there valleys. That being said, Valley’s on a slate or tile roof have a pan that is placed in the center of the valley and the best material to use for these pans is copper. simply for its longevity and not to mention when installed properly its beautiful. the valley is first lined with a thick felt paper, then the copper valley pan is placed and copper nails are placed on booth sides of the pan to keep it from shifting or moving. Then the slate is run into the valley, and cut a few inch’s before the center exposing the copper pan. and the same is done on the other side, and when done right you will see about six inch’s of the copper pan running all the way down the valley.
When replacing a valley there is no cutting involved unless you damage any of the slate tiles taking out the existing damaged valley. That’s where having the right slate and tile contractor becomes the most important part of the process. inexperienced roofers that don’t know there way around a slate roof will break more then they fix.
When removing the existing slate it is placed on the side it was removed from and in the order it was removed and placed usually on roofing jacks. the reason for this is that it needs to go back in the same way it came out, other wise you will sitting there scratching your head wondering what went where. and if put them in the wrong places it will throw your strait line off in most cases and cause it to look crooked .
It isn’t the prettiest thing to look at when everything is all tore out and removed. butt after the pan is replaced and all the pieces of slate or tile get put back in right, well then its just plain beautiful if you ask me. the last picture I will be adding to this is of a good example of a beautiful looking valley with a nice looking copper ridge cap that does nothing but complements the roof I do say so.
While a copper ridge cap is not necessary and there are other forms and methods of capping the ridge, I believe the copper ridge cap to be the best application it is certainly the better looking application.