The percentage of undivided interest in the common elements assigned to each unit shall be set forth in the declaration and such percentage shall not be altered except by recording an amended declaration duly executed by all of the unit owners affected thereby. The undivided interest in the common elements may not be separated from the unit to which such interest pertains and shall be deemed to be conveyed, leased or encumbered with the unit even though such interest is not expressly referred to or described in the deed, lease, mortgage or other instrument. The common elements shall remain undivided and no owner may exempt himself from liability with respect to the common expenses by waiver of the enjoyment of the right to use any of the common elements or by the abandonment of his unit or otherwise, and no action for partition or division of any part of the common elements shall be permitted, except as provided in section two, article eight of this chapter. Each unit owner or lessee thereof may use the common elements in accordance with the purpose for which they are intended. The maintenance and repair of the common elements and the making of any additions or improvements thereto shall be carried out only as provided in the code of regulations.