Exposed nails can cause leaks in asphalt shingles. Shingles should be installed starting at the edge of the roof with the next course covering the nails of the last course.
Yes they do. As the shingles warm,cool and move this makes the hole bigger in the shingle. Eventually water seeps in around the nail head and under the shingle.
Yes, leaving the nail exposed may cause a leak. You should try to overlap a shingle over the nail head. If you must leave a nail head exposed, seal it with asphalt roofing sealant.
The exposed nails could cause minor leaks, it is best to just take a hammer and pound them back in. If the same nails keep coming up, replace the nail.
No they don't cause leaks in shingles but they can. Normally they don't but I can see how an exposed nail would cause the leak. To prevent this, use sturdier nails.
