La. Civ. Code art. 513
Current with changes from the 2024 Legislative Session
When one used partly his own materials and partly the materials of another to make a new thing, unless the materials can be conveniently separated, the thing belongs to the owners of the materials in indivision. The share of one is determined in proportion to the value of his materials and of the other in proportion to the value of his materials and workmanship.
La. C.C. § 513