Texas Property Code - PROP § 82.109. Quorums

(a) Unless the bylaws provide otherwise, a quorum is present throughout any meeting of the association if persons entitled to cast at least 20 percent of the votes that may be cast for election of the board are present in person or by proxy at the beginning of the meeting. The bylaws may not reduce the standard for a quorum to less than 10 percent.

(b) Unless the bylaws specify a larger percentage, a quorum is present throughout a meeting of the board if persons entitled to cast at least 50 percent of the votes on the board are present at the beginning of the meeting.