Q: How can I fill the many large nail holes on each of our hardwood steps?
A: There are all kinds of good wood fillers/putty on the market. You or the stair company should be able to find a colour with an exact match that would better hide the nail holes. The company here in Toronto where I buy a lot of my flooring supplies carries a line called Color Rite www.colorriteinc.com. It comes in more than 450 colours.
I don’t think I could comment on how the stair people installed the treads, but I would think the nail hole should have been rather small in diameter. Why there would be “many” nail holes on each step is something I could not explain. I would have thought they would have used an adhesive and 2-4 nails if needed.
Related Q: We have an old cottage in France. The original, old oak floor boards have holes in some places. Is it possible to patch them?
A: There are numerous wood fillers on the market, often somewhat close in colour with a certain species of wood. Or a product such as Color Rite is a tube/caulking type filler which comes in hundreds of colours. You should likely be able to find something close to what you are after.