Me. Rev. Stat. tit. 10, § 3251

A person who performs labor or furnishes labor or materials, including repair parts of machines used, or performs services as a surveyor, an architect, a forester licensed under Title 32, chapter 76 or an engineer, or as a real estate licensee, or as an owner-renter, owner-lessor, or owner-supplier of equipment used in erecting, altering, moving or repairing a house, building or appurtenances, including any public building erected or owned by any city, town, county, school district or other municipal corporation, or in constructing, altering or repairing a wharf or pier, or any building thereon, including the surveying, clearing, grading, draining, excavating or landscaping of the ground adjacent to and upon which any such objects are constructed, or in selling any interest in land, improvements or structures, by virtue of a contract with or by consent of the owner, has a lien thereon and on the land on which it stands and on any interest the owner has in the same, to secure payment thereof, with costs. If the owner of the building has no legal interest in the land on which the building is erected or to which it is moved, the lien attaches to the building, and if the owner of the wharf or pier has no legal interest in the land on which the wharf or pier is erected, the lien attaches to the wharf or pier, and in either case may be enforced as provided. If the owner of the land, building, wharf or pier, so contracting, is a minor, the lien exists and that minority does not bar a recovery in any proceeding brought to enforce it.