Lam header stock. Aluminum planks are another option, but they are pricey. The shaky nature of the beast, especially when working 25-feet above grade, should command the ultimate respect from workers. But amazingly, this is not always true. And workers often cleat planks together to create a wider walkway.
Careless behavior causes most pump-jack accidents.
OSHA insists that pump poles must be spaced less than 10 feet apart when wooden planks are used. Seldom are the prescribed guardrails, midrails, endrails and toeboards installed on residential applications. Poles must be braced at the top, bottom and every 10-feet along the height of the pole. And the plank ends must be secured to the pump foot. Poles are a weak link in pump staging.