Filling large gaps in wood floor

Q: I live in a 200 year old house that was nicely restored about 40 years ago. Our living room has a pine plank floor, which was finished in shellac (I think). The boards have separated over the years and there are large gaps ranging from 1/16″ to 3/4″ of an inch. Since the boards go under the walls there is no way to lift and move them. I also don’t want to refinish the floor, as it is rather striking as it is.

What was in the gaps previous seemed to be a mixture of clay, sawdust, hair, and maybe glue (very old-timey). I have cleaned all of this out.

My current strategy is to fill the large (3/4″) gaps with a strip of wood (dyed and finished to match), and use dyed hemp rope in the medium sized gaps. I might use dyed hemp rope for the bigger gaps as well. If you have any other suggestions, I’d be grateful. I also wonder if there is something to put in the smaller gaps that won’t require refinishing the boards.

A: It sounds to me you’ve got a good grasp of how to take care of these gaps. As for the small ones, there are numerous coloured fillers in jars and tubes you can search out. Push it into the tiny gaps and wipe the residue off the surface with a damp cloth.

Related Q: I need to repair large gaps, in seams in several spots, in the old hardwood floor of our upstairs bedroom. These are bad enough (about 1/2″) to allow any liquid to drip through and down to the ceiling of the 1st floor. I had planned to mix sawdust and Elmer’s glue, let it harden and sand it level. Any comment or suggestion would be appreciated.

A: I would likely try some version of your suggestion, except I would probably use Gorilla polyurethane adhesive or equivalent. You would have to stuff something into the large gap to hold this adhesive until it starts to set though, so it doesn’t just run through to the ceiling. Also, you would have to apply painters tape to the boards on each side of the gap because this adhesive expands as it cures and you don’t want it all over the surface of the floor.

When it has dried, cut the excess off with a knife, preferably to below the surface of the floor. Then use a colour match wood filler to just glaze over the top so it doesn’t look too obvious.

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