Thread: Shingle Tab edges raised

inspected a house both yesterday and today that had the same condition where the ends of the three tabbed shingles were raised all along a vertical line of shingles along several sections of the roof in an alternating fashion. (Photos). In today's case, every single home in this cove showed the same condition and in the majority of cases, it was on the west side of the home with some smaller sections being located on the south side. What causes this? I have yet to see any damages related to this condition and find it quite often in homes, always in straight lines and usually several rows apart.

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I can't tell from this one fuzzy pic, but does it look like the roofers bent the shingles on the ends so they could nail the end of a shingle below? Are those all ends of shingles, in other words?
Instead of laying a diagonal pattern, they lay a swath of shingles straight up to the ridge, then slide over and start another swath. Lazy pattern.

I agree with John, it looks like a vertical racking install.

Dom.

I would have to agree with the vertical racking as well...as this is what I saw on each of the homes in that cove...all built by the same builder about six years ago, all with the same pattern and pretty much similar spacing.

I would offer an alternate explanation for the raised ends of the shingles. When 3-tabs are run up in a vertical fashion, only the free overhanging edge is bent up to nail the shingle tab slid in underneath. If the bent shingles never flattened, which is unlikely, only the leading edges would be bent -- either all right side or all left side, not every row as shown in the photo. The shingles may be curling because the tabs were never nailed in the region of overlap! As the shingles age and shrink the free ends are free to move slightly allowing the curl.

Roofers who run shingles in a vertical fashion will run three or four abreast up the slope, so curling would only occur where the free edge runs up the roof.

Next time you encounter this lift up a curled edge with a flat bar and see if there are nails beneath.

Thanks Bruce, I will try this.

Several issues contribute to shingle curling.First and foremost is inadequate ventilation.Trapped moisture or excessive moisture is present on the underside of a shingle.

I have seen shingles curl a few years after they were installed.The roofers installed the roof over saturated felt/underlayment.,that is usually from the felt/underlayment being exposed to heavy moisture from rain/frost/snow etc. and not being allowed to dry prior to installation..Then add the inadequate ventilation factor and your roof system is doomed to curl.Also sometimes curling is worse in colder weather or damp weather.

If the curling is addressed early enough in its stage further damage can be controlled by adding proper ventilation.

Racking/Vertical shingle installation method is allowed for installation procedure.However I feel that the pattern of each individual shingle ran vertical on every course is aesthetically unappealing.

A Stair step/diagonal style method of installation allows IMO the shingles to blend better and provide a much better looking installation than those unsightly roofs that are racked.

Most roofers who swear by or are settled into the Vertical Rack method do so because of either their inability or lack of experience to hold the vertical lines.We install only 6" offset stair step applications.It takes alot more craftsmanship and attention to detail to hold the every other line matching from start to finish than what rack method installers are willing to give.

Several shingle manufactures have products that have an installation procedure that calls for a vertical rack method as the ONLY installation procedure allowed.Certainteed and Owens Corning have Super heavy weight designer shingles with rack only method.