Here is a more close up picture.
What would you put under this??

{{!gwi}}

You never caulk shingles. You stain them. Looks like they are already sloughing off the paint, which will make your job easier. Shingles are of a very soft wood (like cedar) which tends to shrink and swell as it cycles through rainy/dry periods. Caulk and paint do not help. Stain is the best finish for shingles in climates that see rainfall. Replacement shingles should be obtained pre-dipped in stain so the overlapping areas are also covered.
Casey

Yes they are cedar I believe ~ but I believe that these type of fish scale shingles are usually painted? The paint that is coming off of them was probably put on over 20 years ago. I don't think they would have been stained. It is not the type of shingle that would have been stained, though I know of what you are thinking. Not cedar shakes (I think that is the term?) but fish scale siding. Thanks for the reply.

Yes, I see that they were painted in the past, and I also see how well that has worked out for you, i.e.: all the paint is peeling off. Repainting will repeat the process. Removing the rest of the paint and applying a solid color stain will at least be trying for a better outcome.
Casey

I see, so they would have originally been stained with a color stain. I didn't realize that they weren't ever supposed to be painted, and I have never seen any that were not. I will have to do a search and get some ideas. This will drastically change what our plans were for them. The entire top third of our house is covered with them as is the majority of our front porch. It was all painted when we bought the houe, as are all of the houses in the city with fish scales. I would love to see some examples of houses that have the fish scales stained. Thanks again!

Rather than try and remove the paint on those shingles, if I were you I'd just take them off and flip them over to stain them, because they probably aren't painted on the back. You'd have to sand the sides, but it would be a lot less work than trying to get all the paint off.

Carla in Sac

While I don't disagree that staining may be a preferable way to treat shingles, painting them is not all that problematic and they will often hold paint better that other types of siding. The proposed solutions of either stripping off every last bit of paint, or removing all the shingles and flipping them over both sound like a little much for me.

How about scraping, sanding to feather edge what is left, and applying a high quality primer before re-painting? No need to caulk (except maybe around windows, etc). Oil primer is probably best, as it will soak into the bare wood better, or add floetrol to latex primer. If you top it with a high quality acrylic paint, you should get another 20 years of service.

20 years for paint is pretty good.