Use solid soffit material and finish it like you would a porch ceiling being sure to angle it slightly away from the house to direct any water that falls through the upper deck to gutters on the outside edges.

The ceiling gets a material that stands up to weather and basically is finished it can be toungue and groove or very simple . The upper deck will require so work to make sure water is directed so for that you need a good pro. That upper deck hopefully was built to have a bit of slope . A picture of that whole area from further awy to show both would be ahuge help.

Bead board, painted a very light blue.

Agree with Norwood architects. Contacting a local company to get a quote will be your best bet.

Thanks everyone! Lyn, I was thinking the same, as we get alot of birds building nests, maybe that will help deter them. Oh, and bugs! Loved seeing that on porch ceilings in the South!

Many people leave open beam ceilings indoors and out. Spend the budget on great fans, lighting, outdoor furnishing, and beautiful landscaping beyond the deck.

Do a Google search for: "wood ceiling over deck" and many great images will pop up.

Some inspro

Exterior Patio Dining Under Trellis · More Info

prime and paint would be a good start. and it will lighten it up too.

try the white or the pale blue

What @Norwood Architects suggested was to close the bottom off with a drain system. My son recently did a 2nd-story deck, and the customer requested a drain system

We did the system that @Norwood Architects suggested in a new build, crisp and clean ceiling and keeps everything on the lower level dry - i am a fan!