Although I had thought that it would be possible to take undamaged board sections from the center of the room (where a rug would be) and use them to repair damaged sections, for my floor, this turned out not to be an option. Over time, each board changes in ways that makes it no longer interchangeable with most of the other boards. This is due to sagging, wear patterns, slight twisting, reacting with the joist underneath and the adjacent boards, expansion and contraction. It may be possible in a limited way, but overall, it is not an option that would have worked for me.
I found it easier to scrape off the finish before removing any damaged sections. This is partly because this gave me a better view of the challenges faced with each individual board, and partly because once you start removing sections of boards, the remaining boards are more likely to have chip outs and cracking.
“Photograph 1” shows a rotted through hole in the floor created with just a little foot pressure on the left. It will need to be enlarged to remove the “not so rotten but still bad” sections. On the right is another hole that is almost completely ready for replacement boards. There are a few ends that need to be straightened and squared up.
Before you remove any boards or sections of boards, plan ahead. You should stagger the ends of boards so that no two adjacent boards end on the same joist. This may mean that you need to cut out more than what is necessary, but it will help your repairs blend in better with the existing floor. Otherwise your eye will be drawn to any spot like this.
A multitool saw blade can be used to make the initial end cuts for the damaged sections. These cuts don’t have to be clean through at first, just enough to prevent surface splintering when the damaged board is finally removed, about 1/8 inch deep.
Make your cuts centered on the floor joists. The old nails that fasten the floor boards to the joists are useful guides for this. Once the ends have been cut enough to prevent bad surface splinters, you can use a rather aggressive drill bit to remove more material. The multitool saw blade can then be used to cut along the sides through the tongue portions and then to clean up the ends of the boards that you are keeping.
An aggressive drill bit is really useful for removing wood material near each end of where you are cutting out. The sides (where the tongues are interlocking the floorboards) can be cut with a multitool saw. It can then be used to clean up the ends.
“Photograph 2” shows new boards cut to fit into their proper places. Because they are individually cut to fit into place, they were labeled on the reverse side to indicate their order and direction. Otherwise, it would be like trying to finish a jigsaw puzzle without the picture on the box.
These replacement boards will be stained to match the other bare original boards before nailing them into place. This first stain color will be chosen to match the old bare boards rather than the finished color. They will get another coat of stain when the entire floor is stained with the finished color and then additional stain if and where needed to blend in better with the original boards.
I had also thought it would be possible to buy new to tongue and groove boards from the local big box home store, but even though the label says 3/4 inch thick like my floor boards, they are actually about 3/16 inch thinner. Also, in places where only a small section of only one board needed to be replaced, a single tongue and groove board would be tough to fit with its neighbors because of the tongues getting in the way when putting a new board between two existing nailed down boards.
Odd as it may seem, my old floor had some boards that are 3 and 1/2 inches wide and others that are 3 inches wide. It’s a very subtle difference that you might only notice once you know to look for it, but it was another reason that new 3 and 1/2 inch tongue and groove floor boards could not be used for repairing some of the larger sections of damage.
Standard 1 inch by four inch pine boards (actually dimensions 3/4 inch by 3 and 1/2 inches) were what I used with very little difficulty. I used a table saw to rip cut the width to 3 inches when needed.
“Photograph 3” shows extra steps that needed to be taken because my house was built without the use of any subfloor material. The single layer of floor boards were just nailed directly to the floor joists. Pieces of 2 x 4 were used to support plywood sections installed between the floor joists and flush with the floor joists.
The plywood provided extra support and prevented cold air from under the house from coming up through the spaces between boards. If I could have used tongue and groove boards, this extra step would not have been necessary.
The board marked “A” is a replacement board cut to size before staining and nailing in place. The boards marked “B” are 2 x 4 sections that have been secured to the floor joists. A small piece of plywood marked “D” was used to ensure that the 2 x 4 sections were secured correctly at the correct depth so that the actual plywood sections that they will eventually support can be flush with the tops of the floor joists. The board marked “C” is a 2 x 4 that has been secured to be flush with the top of a floor joist. This is only because it is the one closest to the wall, and so it would be impractical to install a plywood support there.
These photographs were taken November 2014. This was the last section of boards that I had to replace, and so I hope they show what I’ve learned from the other five damaged sections that I replaced before these.