Meetings and records. The presence of four members of the Board shall be necessary for a quorum and the concurring vote of four members shall be necessary to effect any decision before the Board. The Board shall keep minutes of its proceedings, showing the vote of each member on every question or, if any member is absent or fails to vote, indicating that fact, and shall also keep records of its examinations and other official actions. Every rule, determination, regulation, amendment or appeal thereof, and every order, requirement and decision of the Board shall immediately be filed in the office of the Board.