In our building, the president votes on all matters before the board and not as a tie breaker.

As for Roberts Rules of Order, this NYTimes article, Q and A, By SHAWN G. KENNEDY Published: February 23, 1992:
Absence of a Quorum Question: I live in a Mitchell-Lama co-op. At a recent shareholders meeting there was a discussion about what action is taken in the absence of a quorum. An attorney for the housing company said that Roberts Rules of Order are not recognized as an authority on parliamentary procedure. Was he correct? . . . Theodore Smith, the Bronx Answer: Yes. Roberts Rules of Order are not legal guidelines, although they are time-honored procedures for conducting orderly meetings. Any official meeting of a co-op in New York State during which business is conducted would have to conform to the state's Business Corporation Law.

See:
http://query.nytimes.com/gst/fullpage.html?res=9E0CE7DB1331F930A15751C0A964958260


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The Cooperator had an article that opined:
Liberty Court Condominium Residential Unit Owners Coalition v. The Board of Managers of Liberty Court Condominium Lesson: Calling for nominations of candidates for board membership from the floor at the time of a board election is a "fair and effective method" for nominating board members.

The bylaws of many cooperatives and condominiums do not specify how to nominate candidates for election to the board. It seems that Liberty Court Condominium's bylaws did not specifically address how candidates must be nominated, but provided that unit owner meetings are to be governed by the current edition of Robert's Rules of Order or other rules acceptable to the majority of unit owners present at the meeting. A coalition of Liberty Court owners wanted precise rules covering the nomination method and sued for a bylaw amendment. The coalition lost and the Appellate Division, First Department, gave some guidance on this issue.

The court explained that the statutory requirement that bylaws provide for the nomination of a board is satisfied by Liberty's bylaw provision referring to Robert's Rules of Order. Like many co-ops and condos, Liberty's board accepted candidate nominations from the floor of the meeting. The court recognized that accepting nominations from the meeting floor is a "fair and effective method" for the nomination of board members. Notably, the court was impressed by the fact that the condominium also customarily delivered a pre-meeting notice of nominations and decided that such notice comports with Robert's Rules of Order and gives "fair and effective notice."

See:
http://www.cooperator.com/articles/1028/1/From-the-Court-to-the-Board/Page1.html