Gravity and perhaps roofing cement.

 

Hard to help with no photo.

 

Thank you.
So in the picture below (sorry for the poor drawing) the only thing that keeps water from going under the next set (sheet?) of shingle, in red, is gravity?
Are the sides of the shingles water tight, somehow?

 

Water runs downhill. And the installation instructions for shingles specify the amount of stairstep that each course makes. So if you follow the mfg instructions, water is not going to be able to seep over (for example) 7" before it runs downhill 5".

This assumes the shingles are not installed on a low slope roof, which would increase the likelihood of a leak.

 

The leak is around the bottom left corner of the skylight. I lifted a couple shingles directly on the left on the skylight seating on the flashing and it was really wet under them, thus my questions.

 

Would need to see the sides of the skylight. There should be step flashing on every row. Looks like someone already gooped the hell out of it. You typically never caulk the bottom edge of a shingle or flashing. All that will do is act like a dam and cause any water under there to back up behind it.

 

I don't have a picture but there is a step flashing.
So should there be roofing cement runing verically under all the shingles touching the step flashing?

 

Hopefully the roofing guys show up soon with some additional advice. That flashing is all wrong. I see pieces and I see exposed nails. There's a whole lot that isn't right in the pictures. Flashing a skylight is tough to do the right way. What you have to do is going to involve some serious and expertise work. If you rely on roofing cement for anything other than a very short-term fix, you're going to be up there repairing it all over again in short order.

 

I have 2 different roofers that say they will come the next day and no one has show up. They don't answer the phone either anymore.
Very frustrating.
I'm afraid I'll have to do it myself.

 

No, stepflashings do not need sealant at the seams. Its a real diy move to just go caulking everything up with tar... it just creates a mess. Typically a roofer who is going to stand behind his work would want to replace the skylight with a new one that comes with a flashing kit. Not surprising that no one wants to do it.

 

Flashing should be done in such a manner that caulking is more for looks then anything. If I was fixing that .all the shingles around the vent and skylight wood come off and things reflashed with ice and water and metal flashing. Sadly what you have now is a gooped up mess. Everything has to be done so everything flows down hill.

 

Hi all, new to this forum!... and I need some help...
I have a roof leak between a skylight and a bathroom vent. They are about a foot apart. No roofer seems to want to do the job so here I am trying to figure it out.

Before I take the shingles out, there is one thing I don't understand:
How is the water not going under the shingle where the flashing (for the vent or skylight) and the shingle meet. I've watched a lot of videos online and I just don't get it.
A vent pipe for example: the flashing goes around the pipe then the shingle on top of the flashing (except the bottom). How is the water not going under the shingles that end on top of the flashing?? not like there is a seal under each of the shingle's sides.

Bad flashing job,look how top left is different than right side. Over time that could be the difference. Find a sheet metal company that makes custom flashings and knows how to make them for skylights

 

Thank you all for your answers. This forum is great!
I will try to find flashing that works for this Velux and redo it as well as replace the fan vent.
Living in Cleveland OH with cold temperature, should I put roofing cement under the shingles I replace?

 

If you have to Velux should able to provide a new flashing kit for the window. And sealant should only be used to stick the shingles down. dabs , not a continuous bead. You should flash around the vent all the way over to the skylight. making sure it is only will be under the shingles then step flash the skylight over top of that. Like said before do so everything will runn down hill.

 

Yes if it's cold you'll want to seal the shingles with just a couple dots of tar.
You should be able to get that flashing kit, but if you've never installed one it may be best to pay someone. At the very least follow velux instructions they have videos I believe.

 

I can't speak to the expertise in this youtube video, but, it's a place to start on how to re-flash your skylight.

 

Thanks for the video.
Looks like they have the flashing kit at my H.D.
I looked at their instruction and it doesn't look too complicated. The hardest part will be to find a time with no rain or snow.
I went to tarp the roof so I took a side picture for the curious.
I can lift the bottom shingle of the step flashing and there is water/mud under.

 

Of course there is. Water can get under your shingles where they meet the skylight on the side. And you've caulked the bottom edge of every shingle so that water can't get out. So it will obviously be wet and maybe muddy under the shingles. It could very well be that the entire problem is because of that caulking.

 

The prievious home owner left us with a lot of surpises... we moved just a few month ago.
I just want to rip off all the shingles and look how it is under.

 

Ha, welcome to the club! That's why many of us are members on here. I know my own house was a disaster from the poor workmanship done by previous owners. House was built in 1923. The roof started to leak. When I went to remove shingles, I found not one, not two, but THREE layers of shingles on the house. In speaking with the previous owner he insisted that when he lived there he took off all the old layers and only one was on the house when I purchased it. Not true.

The best advice I can pass on is to take one project on at a time as you can afford it. Being in Cleveland, it looks like bitter cold will be visiting you next weekend. This coming week doesn't look too bad.

 

Yep, that is the thing to do.

 

Spent the afternoon on the roof. Started tearing out around the exhaust vent and it wasn't pretty. There was one screw holding it at the bottom and that was it. It was pretty wet under the vent too.
So with the time it took me just to tear out the shingles around it, I decided to not touch the skylight. I just replace the vent and put the new shingles around it.
We'll see at the next rain...