Nails directly under butt joints

Hi. I hope I’ve to the right place for some practical advice. I’m having a roof done. During a work break, I went up the ladder to have a casual look at the job in progress. I noticed a nail directly under a butt joint. (The shingles had not yet stuck together, so the nail was visible from the angle I was at.) This seemed unusual to me - “can’t that leak ?” This was from just inspecting a small portion of the roof that I could see from the top of the ladder (I did not get up on the roof), so I suspect there are more nails under other butt joints.

From other perusing online it seems nails under the butt joint can be a source of leakage. I’d really appreciate any constructive advice about how to deal with this now with my roofer. The job is pretty much done now. Any comments on the leakage risk ? Should I ask the roofer to inspect each of the butt joints, and remove any nails and seal them with something ? (not sure if that is practical).

If it helps, my roof is somewhere between 7/12 and 8/12.

The nail will eventually leak. What shingle and offset did the roofer use?

It’s not a certainty that the nail in the butt joint will leak, it’s less than desirable though.

We roofers have seen countless exposed nails over the yrs that did not leak, some do most don’t.


rooferama, and Axiom - thanks for the replies. The shingle is : “BP Everest 42”. This is an architectural shingle made in Canada. I read the installation instructions for this here ( and all they talk about is ensuring the nails are located on the proper ‘line’ and driven in straight and not too far. They don’t talk about a particular positioning of nails on the line, or particular offsets. So, the instructions don’t seem to be prescribing anything that would prevent nails directly under but joints.

Nevertheless, what I’m really looking for now is practical advice on what I can ask my roofer to do about this ? Inspect each butt joint and apply roofing cement to any nail underneath one ?

If they are using the proper stagger & nail pattern the nails will all be 2" or more from a butt joint.

When a nail does fall in a butt joint the best course of action is to replace the shingle with the next best thing being caulk over the nail head.

This is an issue if this is something they are doing on a regular basis, not an issue if it is a one off or sporadic.


CT free[quote=“Alfreds, post:4, topic:25612, full:true”]
Nevertheless, what I’m really looking for now is practical advice on what I can ask my roofer to do about this ? Inspect each butt joint and apply roofing cement to any nail underneath one ?
Yes, i think its reasonable.
Its what needs to be done anyway.
He should have done it before you saw it.
Hopefully it was a mistake and not a pattern of it.
If it is a pattern of it, than it especially should be done.
A lot of 6nail roofers get the nails Too close to the Seams.

I space the next nail about one foot from the nail at the end of the shingle.
I have a 42 inch shingle.
I space the remaining 4-5 nails evenly across the Approx 30 inches i have left.

I especially giggle when i see the manufacture instructions show the nails evenly spaced across the shingle even though that is dead wrong.
Every manufacture has their instructions wrong.
Excuse me, If you are only 4 nailing, than its perfect.
But the instruction spacing for 6 nailing is wrong.

Thanks for all the replies so far. I sincerely appreciate it.

My roofer is telling me not to worry about this. He says the butt joints will seal over the nail preventing a leak. I respect his view but have difficulty seeing how this could be the intended design or intent. My intuition is that while some/many of the butt joints might seal, a significant number will not as there is no shingle overlap and no gravity pulling the joint together. (Not to mention the nail underneath which would prevent the shingles from completely fusing with the shingles below.)

Do any of you know if the two adjacent shingles in a butt joint are designed to fuse together preventing any water at all getting thru the joint ?

Absolutely not. He is bullshitting you. It is true that it quite possibly will never leak but the “fusing” is not accurate.


He’s full of shit, to put it bluntly.

Its good practice to avoid the waterline but I myself am guilty of getting 1 or 2 in there. If you got a good stagger its easy to avoid it but guys you work with sometimes lose the stagger and introduce much longer offsets (usually new guys lose a perfect stagger when going over vents).

I hear that! I lost my perfect stagger and had to quit drinking…