2010 California Code
Civil Code
Chapter 2. Accession To Personal Property

1025.  When things belonging to different owners have been united so
as to form a single thing, and cannot be separated without injury,
the whole belongs to the owner of the thing which forms the principal
part; who must, however, reimburse the value of the residue to the
other owner, or surrender the whole to him.


1026.  That part is to be deemed the principal to which the other
has been united only for the use, ornament, or completion of the
former, unless the latter is the more valuable, and has been united
without the knowledge of its owner, who may, in the latter case,
require it to be separated and returned to him, although some injury
should result to the thing to which it has been united.



1027.  If neither part can be considered the principal, within the
rule prescribed by the last section, the more valuable, or, if the
values are nearly equal, the more considerable in bulk, is to be
deemed the principal part.


1028.  If one makes a thing from materials belonging to another, the
latter may claim the thing on reimbursing the value of the
workmanship, unless the value of the workmanship exceeds the value of
the materials, in which case the thing belongs to the maker, on
reimbursing the value of the materials.



1029.  Where one has made use of materials which in part belong to
him and in part to another, in order to form a thing of a new
description, without having destroyed any of the materials, but in
such a way that they cannot be separated without inconvenience, the
thing formed is common to both proprietors; in proportion, as
respects the one, of the materials belonging to him, and as respects
the other, of the materials belonging to him and the price of his
workmanship.


1030.  When a thing has been formed by the admixture of several
materials of different owners, and neither can be considered the
principal substance, an owner without whose consent the admixture was
made may require a separation, if the materials can be separated
without inconvenience. If they cannot be thus separated, the owners
acquire the thing in common, in proportion to the quantity, quality,
and value of their materials; but if the materials of one were far
superior to those of the others, both in quantity and value, he may
claim the thing on reimbursing to the others the value of their
materials.


1031.  The foregoing sections of this Article are not applicable to
cases in which one willfully uses the materials of another without
his consent; but, in such cases, the product belongs to the owner of
the material, if its identity can be traced.



1032.  In all cases where one whose material has been used without
his knowledge, in order to form a product of a different description,
can claim an interest in such product, he has an option to demand
either restitution of his material in kind, in the same quantity,
weight, measure, and quality, or the value thereof; or where he is
entitled to the product, the value thereof in place of the product.




1033.  One who wrongfully employs materials belonging to another is
liable to him in damages, as well as under the foregoing provisions
of this Chapter.