Green’s Dictionary of Slang

(Irish) a cheap wooden seat at the cinema.

1970		C. Brown Down All the Days 41: To sit enthralled on the seemingly unending rows and terraces of ‘woodeners.’.
1981		(con. c.1920) P. Crosbie Your Dinner’s Poured Out! 121: At the Penny Rush, there was no class distinction. For a penny you were put into either the ‘Woodeners’, the ‘Cushioners’ or the ‘Upstairs,’ according to your place in the queue.
1985		M. Johnston Around the Banks of Pimlico 86: The queue for the Tivo was an exercise in self-inflicted torture. We would all line up for the woodeners outside the lane in Francis Street .