What are your opinions on roofers using a closed valley on a California cut using 3 tab asphalt shingles. We are in central NC so we are more susceptible to rain and higher winds.
The California roof valley performs adequately on steep slope roofs, of 6:12 and up. On steep sloped roofs, water is less likely to travel laterally along the roof. On low slope roofs, water may travel sideways and may get beneath the horizontally laid shingles. Installing a California-style valley may void your limited warranty. It may also violate building codes in your area.
From IKO:
https://www.iko.com/blog/open-roof-valley-vs-closed-valley-roofing/
1 Like
Do you have any pictures?
Sorry it took so long, I just saw were to upload the pictures. I have a lot more of them. I was checking some of the manufactures websites and all I have checked so far are ok with a California Cut on dimensional shingles, but not with 3 tab.
Thank you. That link was good info.
Although that installation may work, I think a woven valley would have been a better choice, especially with higher winds.
Here’s another thread on the subject.
Closed-Cut Valley - Specific Inspection Topics / Exterior Inspections - InterNACHI®️ Forum
2 Likes
That’s not technically a California valley. It is a closed cut valley though. 3-tab shingles should never be used on a true California valley.
1 Like