Wood – Floorboards have come loose

Installing hardwood flooring over concrete is generally not advisable for multiple reasons. Two of these reasons are: 1) oftentimes the concrete is moisture permeable, which means that any solid wood floor installed directly to the floor will buckle irreversibly; 2) typically solid wood floors are nailed to the substrate, which is not an option with concrete. One can install 1.5" sleepers on top of the slab to provide this nailing substrate, but this affects significantly things like ceiling height, door height, countertop height, etc. So this is generally not done as a remodel project unless you're remodeling the whole thing. One thing I would recommend as a compromise is finding some way to seal the slab, say with an epoxy paint, and then gluing an engineered wood floor to it.

First, a disclaimer: Make sure the wood you are going to use will stand up in the environment you're placing them in. You may be better off using these with the T&G on an indoor project. Weather outside will quickly weather non-pressure treated wood, and decks typically require thicker boards than you'd have inside since they don't have a sub-floor.

For long cuts along the length of a board, the best tool is a table saw. And the second best would be a circular saw with a jig. If you don't have plans for more projects like this, or simply need to save space, then the circular saw makes more sense. Setup a jig with a long straight edge that you can run your saw along and clamp it on top of your boards to be cut.

To smooth the edges, a router would be best. You could also use a block plane or sander. I'd be tempted to get a belt sander to make this project go quick and to give me the chance to cleanup the finish on the boards at the same time. A small orbital sander would also work and have other uses around the house, but it would take a lot longer and wouldn't be as useful if you want to cleanup the finish on the boards.

_{This is not a recommendation for a specific vendor, sample images only.}