Q & A - Ridge Caps Blowing Off, What Can I Do?

The ridge caps blew off my roof again, do I need to have them replaced?

Rob asked,  I have a 5-year-old asphalt shingle roof with a 45-foot shingled-over ridge vent on top. A section of 15 ridge cap shingles blew off in Feb 2013. The shingles are cut down 3 tab style. I had a local roofer come out and replace them. They are now coming off again in the same area. We really can’t afford to have these replaced several times a year. Some other homes in the area have many ridge vent shingles missing, and the owners just leave them off. Some have told me that the ridge vent will not leak with or without shingles on top. Should I just leave the shingles off at this point?

Rob, sorry to hear about your problem with the ridge caps.

1. There are many types of ridge vents available for roofers to use. Most are not made to be installed just by themselves and must be shingled over with proper ridge caps or they will leak.

2. The issue of blown off ridge caps could be the length of nails used or the sealant. Most roofers will use for speed, a pneumatic nail gun, and the fasteners do not meet the manufactures specs.

They must be 10-12 gauge, barbed, deformed, or smooth shank roofing nails with heads 3/8″ (10 mm) to 7/16″ (12 mm) in diameter. Fasteners should be long enough to penetrate at least 3/4″ (19 mm) into wood decks or just through the plywood decks. With ridge vents, I would use 2.5-inch comp nails and blind nailed as shown in the picture. { Blind nailing is covering the nail head with the next shingle. }

3. In high wind areas where the wind is prevailing from one direction, run all the ridge caps into the wind or towards the prevailing wind. Doing this will keep the butt of the ridge cap from bucking the wind, and always lay flat. Most roofers want to run the caps from both ends of the gable and meet in the middle, but in some cases like yours, it may be catching too much wind and blowing off. It is acceptable to run the caps in all one direction.

4. Shingles must be able to seal. If this repair was done in Feb. and it blew off again, it may not have got warm enough for the ridge cap to seal.

Hope this helped, Bob

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