1

During a recent rain storm, I noticed a very slow drip of water coming from the center of my (external) garage roof in a few places.

enter image description here

After it dried up, I went to inspect the problem spots and found some rotting and could see daylight through some spots where the nails were.

Close to the front there was a significant amount of torn tar paper and it was even completely free in one spot where I could touch the metal ridge cap that sits atop the roof. (Shown below)

enter image description here

From the exterior, there doesn’t appear to be any major damage to my shingles or cap or anything out of the ordinary that I am able to see from ground level.

enter image description here

Also, after a thorough inspection during heavy rain, there were no other areas leaking other than along the general line of the ridge.

Would like to keep my garage from rotting itself from the inside out, and prevent any foundation damage here, so I would like to address this as soon as possible.

What must be done to stop this leak?

  • 1
    I'm not a professional but you might try flex seal. If you go with this option I would try to find the shingles around those spots and lift up the ones above and spray beneath and maybe if possible spray between the wood and tar paper. – depperm Feb 27 at 23:28
  • 1
    Is that a standing ridge vent ? A close up on the area of the leak would be helpful. A standing ridge is normally seen in barns sometimes garages , hard to tell. – Ed Beal Feb 28 at 0:20
  • 1
    Yes I believe that it is a standing vent. It seems to be the source of the problem. – John Feb 28 at 14:23
1

The ridge vent can allow driving rain in, but for it to be showing water damage, it would have to be getting in during nearly every single rain. Is this area of the garage perhaps where the driving rain comes in or is there possibly something that cannot be seen in the pictures that would be directing more than normal water in?

I don't think the tar paper is supposed to bridge the ridge like yours is. I can't seem to find an install guide online at the moment, but last time I installed ridge vent, we did not have tar paper across the opening and the roof has no water. I wonder if the water is getting on the tar paper and is getting through a nail hole causing this issue.

| improve this answer | |
  • 1
    I suspect that several nail holes could be contributing to the overall problem. I live by the coast and know that water is very prevalent but even during a somewhat light rain noticed the leak still occurring. I may try to apply some sealant to the heavy problem areas as a temporary fix to see if this reduces the problem. But suspect that the ridge cap itself needs replacement. – John Feb 29 at 4:15
  • 1
    It might, but the more I thought about this, the more I think the rain in coming in the vents in the ridge vent, then sitting on top of the tar paper until it finds a nail hole and then soaking into the wood. If the tar paper wasn't bridging the gap, the rain could sprinkle in and spread across the entire surface of the attic or whatever is below instead of pooling. – Matt Anderson Mar 2 at 15:54
  • 1
    It would be relatively easy to cut the tar paper between the ridge vent, I have great access from inside of the garage. – John Mar 2 at 19:22
1

So I hesitate to recommend this as a solution to the problem because it definitely does not permanently address the problem, but it was quite effective for the time being until I’m able to address the problem from the top of the roof at the shingles themselves.

Upon closer inspection of the source of the leak, which required me to cut away the rotted plywood down to the shingle itself at these loose nails of which there were several for some reason, likely due to weather wear, I found daylight clearly shining through in each case. enter image description here

What my fix to this was, which I would argue does not just move the leak somewhere else considering it is at the ridge of the roof and at the shingle vs the plywood, was to take a cartridge of roofing sealant (I used Through The Roof brand which I read has good expansive properties) and with a caulking gun liberally inject it through the holes from the bottom, so it would pass through the hole to the top of the shingle.

While this is not ideal, and does not guarantee a seal as a top down approach would, It does seem to effectively seal the shingle and did not have a single drop of rain or any noticeable signs of moisture in any of the plywood sections at the ridge after several days of heavy rain.

Ultimately, the longer term fix is to seal or replace the shingles from the top side but would recommend this fix as a temporary solution better than just arbitrarily spraying flex seal or a similar product at a rotted board board which was the terminal end of the leak which would still allow water in at the shingle.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.