These are 20 year old wood shingles that have almost 100% UV and moisture protection by virtue of them being covered.  They were stained(not by us) when the house was built.  The bottom portion of the shingles do receive a little bit of late afternoon direct sunshine.

We washed the shingles with cold water and 800lbs pressure.  We used a Crystal Clear stain by Defy towards the top, and even in and around corner nooks.  We then blended in some Cedar/Light Walnut pigment as we got closer to the flooring and the more exposed shingles..

The goal being to bring the top and the bottom together to form a new and neutral tone.  We triple coated these shingles.  Surely they are good to go for a long, long time.