As above photo. Don't forget to tell the counter fabricator, plumber and electrician.

Want best advice? Put the faucet on the counter top . Do a six to ten inch splash in counter material. Skip the ship lap :) Avoid the cliche.

How dark is the teal? Lighter teal would be better for less contrasting of the 'shape' created by the backsplash....

I think you could get away with this with a good quality wood and the right paint in the backsplash area. But it would still be more susceptible than tile or solid surface. But if you design the whole thing right you could have the top of the backsplash line up perfectly with the horizontal of the shiplap to minimize its' impact.

This Frank Lloyd Wright house has a wood wall in the shower and this house is 60 odd years old. It does not show all that much damage except at the area where the cut edges of the wood meet the tub flange and the faucet/escutcheons). And this is an intact FLW house that is lived in, not a restored museum-like house.

Also of note, the fixtures are pink. Pink bath fixtures were a long time favorite of Wright.

As you can see in our design below we used shiplap in parts, but not all of the bathroom.

Sullivan Island Beach House · More Info

Sullivan Island Beach House · More Info

Sullivan Island Beach House · More Info

Thanks! I'm only doing it on the vanity wall and think I'm going to have a smaller backsplash 3" then just but up the shiplap against the backsplash so its about the same depth.

Think about everyday use and go with quartz backsplash.