I made a mistake in nomenclature. I am asking about house car roofs
with "boards" on the roof.

Many of these boards visible in pictures have lost paint and are
different shades of grey.

It really doesn't matter to me if these were T&G or not, but sometimes
it looks like some of them were replaced making a section of newer
looking "boards". It doesn't matter to me if there was some sort of
barrier beneath the "boards". I just like the variation of color.

I agree that many stock cars had roofs of this type.

I think produce would rot if water dripped on it. A little bit of water
might help cool carcasses by evaporative cooling.

So which cars had these board roofs in the '40s besides Canadian 36 ft.
SS box cars, stock cars and meat reefers?

Ed