??? quest clarification (stage 2)

Doing the ??? quest, and I've gotten all the necessary items to continue, but I already tried and missed the hole once, so I want to be very sure that I know where the hole is so I can drop down quickly. However, checking the wiki, it says the spruce planks in the floor will break, but checking the blocks, there is no spruce planks in the floor of the room. So I'm confused on where exactly the hole will open.