Source of Leak - Roof Itself or Fascia/Gutter?

I need help from experienced roofers, although I’m not sure my question can be answered based on my description alone; I know photos or a visual inspection might be necessary. The source of a roof leak has emerged as the key question in determining how a roof will be repaired by a condo association: Is the source of the leak the roof itself or the fascia/gutter?

If it’s the roof itself, then the entire front half of the roof likely will be replaced (the back half was replaced in January). The front roof is in deteriorated condition, shingles and decking; there was no ventilation before January. Also, a roofer said the shingles were put on wrong. If it’s the fascia/gutter, the repairs will be limited to these even though the roof needs replacing.

I first became aware of a leak in this area in Jan, when I saw a wet spot on the brick veneer exterior of this 2-story condo. The spot extended from under the gutter down the wall about 1.5’ and was about 1.5’ wide. In January the roofer put a new boot around a small pipe in this area, but he still mentioned the pipe as a possible source of the current leak.

A few days ago I saw the exterior wall spot again and it was about the same size. (Both times I saw the spot the rain was moderate.) I entered the attic and saw, at the juncture of the fascia and the decking, rain welling into drops and falling free into the insulation; it wasn’t running down the side of the fascia. The decking appeared wet and very dark (rot? mold? both?) in that area. The next day the roofer came to assess the leak and said the gutter was clear, but I’m wondering:

•	Can rotted decking wick up rain water from a gutter in such quantity that the water falls free? How likely is this? 
•	Can it wick the rain water high enough that it can fall free? I'm not suggesting it would need to be very high, maybe only a tiny fraction of an inch above the fascia, although the dark decking area extended 6-8" above the fascia. About a foot above this was another dark area, but it appeared dry.
•	Can the fascia/gutter be the source of the dripping water leak even if the gutter is clear of débris? For example, what if the gutter was tilted toward the fascia, or rain water was backed-up because the downspout was blocked? Just trying to think of anything that might be going on.

Are there other possible explanations I’m missing?

I’ll appreciate any insight into this.

As you mentioned, tough to tell without seeing it for myself. But I will share what I know.

• Can rotted decking wick up rain water from a gutter in such quantity that the water falls free? How likely is this? ( probably not and is unlikely )

Can it wick the rain water high enough that it can fall free? I'm not suggesting it would need to be very high, maybe only a tiny fraction of an inch above the fascia, although the dark decking area extended 6-8" above the fascia. About a foot above this was another dark area, but it appeared dry. (highly unlikely )

• Can the fascia/gutter be the source of the dripping water leak even if the gutter is clear of débris? For example, what if the gutter was tilted toward the fascia, or rain water was backed-up because the downspout was blocked? Just trying to think of anything that might be going on. ( rarely )

Any leak at the bottom of the roof is usually due to one of the following:

  1. facia board being installed too high. The facia and the roof deck ideally should meet “level” with one another. When the facia is installed too high it causes the very bottom shingle to curl up, thereby creating a small damn where water will first collect and then run horizontally. Water only has to run 6 inched horizontally to make the roof leak at the bottom and thats if the roof was installed properly.

  2. The starter strip which is located directly underneath the very bottom shingle must be staggered roughly 6 inches left or right from the actual shingle that you see at the bottom. If they are both installed one directly in line with the other then you have a leak.

  3. If the roof is more than one layer and the roofers did not properly start off the last nail over by cutting off the tabs of the 3rd shingle from the bottom, then there will most likely be a hump about a foot from the bottom that can create the same dam effect as in answer #1.

Other than these there could be a nail poking through the roof. If its dimensional style shingles there could be a nail located in a bad spot where 2 shingles fit together. And the stagger from one shinlge to the next one up or down could be short, It should be 6 inches minimum but would probably not create a leak unless under 4 inches.

Also if ice and water shield was installed it still should not leak from these causes. Having a metal or aluminum drip edging could also prevent some of it.

Could you take some pics?

Your answer is very informative and helpful. I’m not a roofer, so I myself can’t determine whether my roof has the faults you described, but I can use this as a basis for talking with the condo association’s roofer and maybe the Board. The most important thing is that every fault you mentioned has to do with the fascia and gutter, not the decking and shingles.

Because the shingles and decking are in such poor condition in this area, I still wondering if they also may be contributing,

There are dark areas on the decking that runs along the fascia for about half the width of the roof. They vary in height, going up to several inches in some places. They could have been caused by water running horizontally.

There is only one layer of roofing.

There were “popped up” nails on the backside (north) of the roof that was repaired in Jan. I don’t know whether any were in this area. I’ll ask.

The roofer said the shingles weren’t put on correctly.

I’m in Raleigh NC. Don’t know if roof has ice and water shield; it has asphalt roll roofing. Think it only has decking, asphalt roll roofing, shingles.

Tried to attach pics through photobucket, but it’s not working. Have a friend who may help me later today. This site said my post is too spammy for a new new member and please remove the URLs.

Something urgent has come up and cannot post pictures until later.

LuckyChucky,

Just want you to know that I still haven’t had time to figure out how to post photos - I’m doing something wrong and it’s probably simple. Got word today that the roof is to be replaced so it’s less urgent that I get a diagnosis of the source of the leak. However, some day when I can, I want to post photos to see if they allow you to make a more definite diagnosis.

I want you to know the info you’ve already given to me helped a lot and is greatly appreciated. Take care.

Jann

Leaks happen near top covering edges because of the transition from flexible membrane flashings to inflexible sheet-metal flashings. Technicians should ensure that sheet-metal laps shed water, and they should examine the sealants at these locations frequently.

Pre-manufactured sheet-metal top covering accessories can solve numerous roof-perimeter troubles. Home owners can identify custom-made accessories for copings at parapet walls and reglets at masonry or rising interior walls. These components normally snap together, and technicians can dismantle and re-install them during roof-membrane replacements.

Roof drains that penetrate a roof membrane can be especially troublesome because rainfall that falls onto the roof finally flows over the drain’s seal. Drains should be sufficient to handle heavy rain falls, and they should have a screen that halts debris from sliding down the pipe.

Roofmaster.net,

I have no idea what type of flashings, if any, are on the roof. The front of my roof is scheduled for replacement soon (right now there’s a blue tarp on it). The roofer has been very willing to answer my many questions in the past so I’m planning to show him your post and those by LuckyChucky and ask him about the flashings, etc.

Thanks very much for your help. I think your answer likely will be helpful to others who read it, too.

JannaH,

It our my pleasure to show you the photos that we have about the different types and ways of installing flashing. But the site doesn’t allow us to attach images. We hope to find some ways to help you.

Thank you