Hi,
I have a 12 year old asphalt shingle roof in an area in California with periodic high winds. Recently I noticed pieces of ridge cap shingles appearing in my driveway after a windy period of a few days. I went up on the roof and found the roof to be in excellent shape but the ridge cap shingles falling apart.
Replacing the ridge cap shingles is usually no big deal and there are plenty of good guides out there written by authors such as Mike Guertin.
On this roof, however, the original roofer made the roof cap from layers of stacked shingles four thick. I.e. where you would normally place a single shingle a stack of four is in place. This gives an interesting visual effect that's sort of oriental in appearance.
Here's the question, however. To keep these thick shingle "stacks" in place the roofer used exposed nails all along the ridge. I.e every 4 inches or so is a roofing nail (no doubt necessary to keep them from blowing off). We get very high heat here in the summer (110+) so the adhesive on the tiles should bond nicely. Normally the nails are hidden below the overlaying shingle and you don't have any exposed nails until the very end of the ridge. To which you normally apply roofing sealer. Not so here, all the nails are exposed. No sign of sealer.
Now, that said, the ridge has never leaked. Is there a trick in the fact that you are nailing through 5 shingles (4 in the new layer and one below)? Is this proper roofing technique? I do like the effect and could replace it just as it was originally installed. I wouldn't want to perpetuate a bad practice, however.
I could really use an opinion from someone more experienced than I. My total experience is one 2000' sq ft. house which was originally wood shingle. We converted it to asphalt with the guidance of an experienced contractor friend.
--jhujsak