Quick question...what are your rim boards made out of?? I've been told that I-joists will bounce and squeek if the rim boards they are connected to are *not* a timberstrand or another type of engineered lumber. Using conventional lumber for rim boards (regular spruce 2x12's etc) results in a difference in the expansion and contraction characteristics of the two woods (engineered i-joists to conventional lumber), and the two components over time begin to move at different rates, causing this effect. This can be due to temperature differences, humidity, etc. Considering the comments of your GC, I wouldn't be surprised if this is your issue. The engineered rim boards are significantly more expensive than conventional lumber, and this often means that companies will save a few bucks by mixing the two products. Always at the expense of the home owner.

Let it dry out. The REAL issue isn't the wood floor. It's going to be OK...the ISSUE is the door and the saddle and the WATER that is hitting that area. Redo the door and you should be able to let that wood 'dry out'. Once dry, it will go back to the same colour as the rest of the wood.

If that were my house, I would hire someone to come in and remove that railing completely and have a half wall put in there (higher than that railing, so kids couldnt get on top of it, or fall over that ledge). Those things would drive me nuts with little kids around, or anyone, who could fall and get against it, or lean against it and fall over the edge.

Here are 3 of several responsibilities of a General Contractor: Organizing and managing the jobsite. Hiring subcontractors and managing their quality. Contracting suppliers and vendors. "so I went ahead and hired a guy to install the vinyl planks." Why?"