1. Carpentry. Slang term for OSB / chipboard / flakeboard, a type of sheathing sheetgoods.
2. Studio Lighting. A luminaire mounting apparatus. From www.cinematography.com--What's the origin of the term beaver board? : "A beaverboard, (or pigeon on a pancake) consists, usually, of a 1/8th apple box (sometimes a 1/4 apple box) with a baby plate (with 5/8" pin) screwed into it. It is something made by grips on set."
2. Studio Lighting. A luminaire mounting apparatus. From www.cinematography.com--What's the origin of the term beaver board? : "A beaverboard, (or pigeon on a pancake) consists, usually, of a 1/8th apple box (sometimes a 1/4 apple box) with a baby plate (with 5/8" pin) screwed into it. It is something made by grips on set."