How can I repair a cracked wood floor?

Use wood filler in the color to match the floor. But my question is why is it cracking?

Hi Marcia, do you happen to have the wood floor also in a closet area? If so you might be able to remove some of the wood from that area and then remove the cracked or broken boards with boards from your closet area. It seems perhaps your boards are too wide for the area they've been placed in, so possibly shave off just a small bit of the edge of the boards to give them room to expand when hot weather arrives. Good luck!

Why is it cracking where your getting holes? Is it just rotting away? You can patch the holes with new wood. You would need to add support bracing underneath.

Yes I have. I use 409 Multi Purpose cleaner (lemon scent). Method: Wear rubber gloves. Spray the area where the black spots are sitting. Wipe the entire area (especially the black dots) with your glove. Make sure the entire area is wet. Then wait 2 minutes. Make sure what you just sprayed doesn't dry up. Finally, use a fine weave cotton rag to wipe it all off. Keep rinsing your rag and wiping/scrubbing. For really stubborn ones you can scrape off with a plastic putty knife. I have found by using this method I can get it all off very well. The secret is to let the 409 sit on it for a minute or two and then that fine weave cotton cloth. Works wonders!

P.S. The uncomfortable truth is that this type of fungus comes from manure of any kind - dog, cat or cow. So if you are using black mulch, or have dogs/cats on your property, you will battle this fungus to some degree!

When wood takes on moisture it swells, and it can crack. Large areas of swelling are referred to as buckling and look like this: https://1.bp.blogspot.com/-_6yjAHRbLLs/TWHb34MO21I/AAAAAAAAAFQ/2BEiwGUSAsY/s1600/Buckled+floor.jpg When individual floor boards cup or crown they don't usually crack, but still look bad like this cupped floor: https://www.builddirect.com/learning-center/wp-content/uploads/2018/05/shutterstock_789905404.jpg Buckling can occur with new flooring if the wood flooring is not stacked in the house for a week or two before it is installed. Being flooded can also cause wood to buckle. Cupping is usually due to moisture below the floor that causes the wood to swell at the edges. Should the wood eventually dry out the board profile will reverse and be higher in the center (crowning) than at the edges.

Moisture below wood flooring can be from a damp basement or crawl space, or even a damp concrete foundation. Make sure there is no plumbing leak. Don't use any water while you check the water meter. If either the regular or low-flow indicator is changing you have a leak. If you don't see any movement, make note of the numbers and wait two hours. Any change means water is leaking somewhere. Leaks can be pin-sized and cause extreme humidity and eventually rot. Other causes of excess moisture are a high water-table or if water collects against your foundation after rain.

Wood filler should to a great job

i had original hardwood floors in the house I grew up in, I had this issue too. Nothing was wrong per se, just age and wear. We pulled the offending pieces up single board and one area I had a huge hole to try to blend in. Anyway off to Home Depot I went with board in hand, matched to as well as I could bought what I needed (it was a couple of dollars a board) I cut mine to size myself but they can cut it for you. Then I went home and popped that sucker in stained it to match and BAM. Perfection. After wards when I saw the blending on the hole while no one else can tell I know that it’s new mixed with old.m, I wish I had taken the original floor out of closets used that and then put the new boards in the closets. Live and learn. Lol

https://www.hometips.com/repair-fix/hard-wood-floors.html

Take a good photo to your home improvement store flooring department and ask for their advice on products and application tools.