MOST COMMON CAUSE OF ROOF LEAKS?

I guess as long as we're assuming premature failure I agree with what has been said already, though nobody but Vickie mentioned clogging of parts. In some tile systems (among others) that's a huge factor.

But, then, as always it comes down to the intent of the question which provoked the discussion in the first place, so if we are speaking literally, and if we ascribe a liberal 30% for roofs which have premature problems, well then the remaining 70% (which presumably go full-term) do seem to fail from damage to the material albeit naturally-occurring damage.

In truth, including all the failures I have ever encountered, most were due to degradation of the material. Nonetheless, I still join everyone else in being suspicious of the original statement, and the greatest likelihood of leaks occurring is in the flashing zones, whether because of defective parts, badly-designed parts, or poorly installed parts, and that includes Rocky's perimeter metal, which is also flashing.

GKRFG Said: Roof damage sounds like a storm chaser trying to convince people that they have damage. IMHO most of the hail damage that I see is just normal wear and tear that will have minimal effect on the life span of the shingles. Granted there are differing degrees of hail but the nickle/quarter size hail should not be a concern.

Usually, not always. I saw most of the commercial roofs in Spur, Tx replaced after nickel sized hail. The unusual storm hit in February when the temp was 45 (brittle asphalt) and driven by 75 mph wind.

This is why we don't like it when Haag Engineering incorrectly says that it takes 2" hail to damage a BUR.

Roof damage sounds like a storm chaser trying to convince people that they have damage. IMHO most of the hail "damage" that I see is just normal wear and tear that will have minimal effect on the life span of the shingles. Granted there are differing degrees of hail but the nickle/quarter size hail should not be a concern.

The most common leaks that we repair are caused from poor workmanship, especially at the bottom of valleys that end at a wall. Most of our repair calls are from: 1) deteriorated rubber pipe boot flashings. 2) blown off shingles, usually misnailed shingles. 3) leaking skylight flashings. 4) improper chimney flashings. 5) valleys as mentioned above. 6) poor ventilation. 7) nail holes in the roof left by other trades. 8) wind bolwn rain or snow getting under flashings or into roof vents. 9) garbage ridge vents. There are numerous causes of roof leaks. These are the ones we seem to see the most often. The only shingle damage that I have seen cause a leak from a storm is when a large area is blown off.

Improper workmanship at penetrations, valleys, walls, etc. Though only water resistant, and not water proof, the shingles themselves don't cause the leaks. Flashings are considered water proof, so they, themselves aren't the problem.

I have today's example right here.

I noticed a curious phenomenom today. Leaves hung on step flashing.

A little probing and I find the counter flashing has been cut and installed so it catchees water and guides it behind the step flashing to cause a leak.Several, in fact.

I cut the tips off squarely to stop this leaker.

Hey Roofguy, at least we have one smart guy/gal in the group.

Your correct Vickie

Rain.

Was the question "what caused them" or "where are they from"? :unsure: Flashings don't cause leaks, but thats where they happen.

I would say number #1 is poor workmanship. a close second would be flat to pitch tie-ins, then flat roof edgemetal failure and then failure at any roof penetrations. Am I allowed four answers? :P

Definitely NOT shingle damage. At least from what I see.