If you would like a thick barnwood tongue and groove (T&G) product, but would like to avoid the expense of adding a T&G to barnwood lumber, you might want to consider barnwood lumber that was salvaged with a tongue and groove already on it.
You will need to keep in mind that (1) this lumber will not fit together as well as lumber with a fresh-milled T&G; (2) there will be some falldown to deal with; and (3) this type of lumber often has paint (likely lead based) on at least one face, but if you and your application can deal with these issues, this lumber can provide an authentic barnwood T&G product with some nice cost savings.
Trestlewood currently has over 40,000 board feet of weathered decking with original T&G in stock. Options include:
1.5" x 5" Barnwood Decking with Original T&G
1.5" x 5" Decking with Original T&G and White Paint
2.5" x 5" Decking with Original T&G and Faded White Paint
2.5" x 5" Weathered Pine Decking with Original T&G and Beaded Edge
3" x 5" Weathered Pine Decking with Original T&G and Beaded Edge
4" x 5" Weathered Decking with Original T&G