Robert Allison wrote:
In most cases like this, we have installed drywall over the
shiplap and then taped and floated, textured, then paint.
This also repairs the drafty quality of these kinds of walls,
as the gaps between the shiplap allow quite a bit of air and
sound through the walls, especially on exterior walls.

Robert, thanks for your reply. Do you think the thinnest (1/4")
drywall will be enough, or would we need to put up something thicker?

Thanks,
Elana