Slate roof question

Are these holes from the original fasteners that are missing or are they from an attempt to repair the slate roof by nailing through the slate. I found one nail threw the slate covered with tar. House is 70 years old. Is this about the time that the fasteners give out? Thanks for any info from the slate experts.

Those are upside down slates.

In the last photo, it looks like the slates are installed sideways. That is why you see one hole. That’s what it looks like to me anyways. I’m no slate expert. Call Frank Albert.

I had Frank Inspect my last slate roof for me. I learned a ton.

Juan, not sure what you mean by upside down slates? Are you saying those are repaired slates that were put back upside down?

I don’t know why they upside down. They come with two holes in them for hanging them. Those holes you asked about are the original holes meant for the top. It’s really easy to put the new holes in though. You just hit from the back.

Holes are holes no mater what type of roof. Holes leak.

I won’t presume to be an expert on slate roofs, but thanks for sharing the great pictures! Slate is certainly brittle material and would have to be drilled to take a nail. Holes will let water through, but the question may be if they drain onto solid shingle below or on a joint? Valley metal is rusting out also, from the looks of it.

Those slates are improper because of the holes and need to be replaced. That’s the recommendation.