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Discussion Starter · #1 ·
OK, so I do not roof everyday but on occasion do here and there! As I was doing a cut valley the otherday a thought came to mind. When the non-cut side wraps through the valley using dimensional shingles there is an opportunity for water to collect in the small areas that the laminated pieces are bonded to the base shingle. I assume the theory is that the vast majority of water flows out and over these small pockets what little is left will evaporate with air and sun? Obviously this is accepted practice, but just a thought that came to mind! Obviously one can adjust the pattern at times to minimize these from falling in the throat of the valley, but you cannot always....
 

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You can adjust where your shingles land,by cutting them back or by adding a piece.Just make sure to think ahead about the nail pattern.
 

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We run shingles vertical up the valley to create our clean straight line in valley. These shingles are placed under the cut side in a checkerboard pattern. I feel this gives the best look and protection.
 

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Discussion Starter · #4 ·
I had considered that, which I have referred to as Long Island or Tamko valley. I am using Landmark TL's, these are so thick that the extra layer of coverage would be, perhaps way to much. Also the top of shingle for this color(Shenandoah) is so dramatically different(very golden vs. the finish shigle which is warm reddish color) that this technique would stand out like a sore thumb. Although I think this method of valley work would be so much faster than cutting. Thank god for the guy who invented the "shear". The only down side I have seen so far is the amount of memory in these shingles from the positioning on the pallet. I think do to the extreme thicknesses in certain parts of the shingle. What a nice looking shingle though!
 

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Usually with heavier shingles it is best to incorporate open valleys as they tend to not bend so well into closed valleyswithout cracking, plus the issue you had mentioned originally definitely can pose a problem under the right circumstances.

I honestly do not understand running a starter underneath the cut side as some guys do, it just adds more hump, and the nails tend to be closer to the valley than I would like ;).

The tamko method you refer to here we call the california method. Again the nails seem closer to the valley than I would like, although I suppose it is acceptable. With higher end shingles though I wouldn't be doing that, I think it looks cheaped out, providing you know what goes into a roof :laughing:.

Those landmarks are indeed a very nice looking shingle.
 

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Discussion Starter · #6 ·
So far I have 7 of 12 valleys done,I have not had much issue in shaping into the valley, we have been lucky with warmer than usual weather, and when it gets chilly, I have been using the chimney nearby to do "spot warming! I really wanted to do open cut valleys with copper pans , but the cost was prohibitive(approx. $2K more in materials alone), as open valleys are not common on the coast I figured not a big deal.
 

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I personally think that the california valley is junk. It looks ok, but I think it is asking for trouble. The laminates sometimes direct water under the cut side of the valley, and can slow the shedding of the water. It is in the MSA manual by certainteed, but I'm not sold. The best valley is the open valley, but most of the time with asphalt we end up doing the cut valley. Generally if the money is there, we are not doing an asphalt roof in the first place. Its either red cedar or something else.
 

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You can start in the valley and still get the necessary ofset required by the manufacturer. We do not run verticle valleys. I call them california Valleys. I don't like the look and the protection is debateable. See see points on both sides of the argument.
 

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Discussion Starter · #10 ·
In the same line of conversation. All the literature I have seen recomends that the cut side be pulled back from the valley and opened slighly from top to bottom. This makes sense to me. However, As I drive I look at all of the cuts that I see and rarely are they held back, hard to tell if the are opened slighlty. The cut appears to be less obvious when done in the throat of the valley. Which is corect, I hold them back and pitch them, is there truely a right and wrong?
 
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