The first floor got rained and snowed on repeatedly, and I stored very heavy tools and lumber on it, and even dropped a beam through it in one spot. It was a bit soft in spots, wavy in others, and basically unsuitable to support the 40 year old quarter sawn oak that'll be the finished floor. I also had a dilemma about the stairs---once I added the treads, the first step would have been too high. Solution to both problems was a whole new layer of thick tongue and groove subflooring. I put tar paper between the layers, a step recommended for people building houses to last 100 years instead of the usual 30. Best part of this stage----AnnaMarie came over to drive in the 3 1/2" deck screws. She loved doing so actual construction instead of just watching.
Anyway, the speaker wire for one of them terminated on the other side of a floor joist and I really didn't want to drill a huge hole to get my arm through to grab it and pull it through. I drilled a smaller hole in some cardboard and had my middle kid, Lauren, put her arm through to assure it fit. Drilled the hole through the joist (By specs I could have drilled a 6" hole. This one was 2 1/2") Put Lauren on my shoulders and stood on an OSHA approved paint bucket so she could reach through and grab it. She asked if she could paint afterwards, so I assume she wasn't traumatized by the experience. I think her mom was, though.