"stuck on what semi transparent stain to use"

In CR's tests of semi-transparent wood stains applied to pine boards (two coats) and placed on a roof angled towards the south, none held up by the second year. So the question is whether the roof's appearance after two years -- and if the stain didn't hold up how would the roof look? -- would be worth the effort and cost of staining given that the roof will eventually achieve the appearance you want if left alone.

When I worked in a lumberyard we always recommended Cabot Bleaching stain to get that Weathered Grey look. It works in about 3-6 months of exposure to a nice weathered grey.

The more opaque the stain the better it will protect the wood from the sun.

Thx so much everyone! Does this require additional sealing for protection and or specific & contd maintenc

" natural, weathered grey tone "

That would be a shingle without protection, the Bleaching Oil & Driftwood ray stain just speeds up the process with the Oil and stains it slightly natural now. Typically the most you might do for maintenance would be to clean the shingles if they get dirty of mildewed.

Here below is how the stain appears after a few months.

" are trying to replicate a natural, weathered grey tone "

@BeverlyFLADeziner. stain alone will not replicate the look the OP is looking for.

millworkman, The product I posted was used by architect Steve Giannetti for his mini ranch Patina Farm. https://www.patinahomeandgarden.com/architecture

If the OP is trying to get to this appearance, see pphotos below, that would require something different than what was used at Patina Farm.

In CR's tests, the appearance of only two clear sealer wood stains earned a 2/5 rating after one year, six earned a 1/5 rating after one year, and no product resisted cracking, color change, or dirt. (Note: The stains were tested on boards, not cedar shingles.)

• Consumer Reports Wood Stain Ratings and Reviews ($10/month digital)