How can I fix the cracking wood filler on my 1940s fixer upper floors with no subfloor beneath and joists showing?
We recently purchased an old house from 1940 that needed some serious fixing up. We’ve been working really hard to restore the original floors, starting with the upstairs bedrooms and hallway. Let me tell you, they were a mess! I had to rough sand them twice before filling in the big gaps with wood filler. But now, as I’m sanding and filling again, the filler keeps cracking and coming out of the gaps. We tried different wood fillers, but had the same problem. I know there’s no subfloor underneath, just the joists. My husband had to fix some boards before I started sanding. I feel like giving up on these floors, I’m at a loss for what to do next. Any advice or tips before I call it quits? I even included some before and after photos, but I’m feeling pretty defeated.
There’s no subfloor in my second story. Only one room had the original wooden floor salvaged. Now, I’m in the process of ripping it out because the boards tend to move over time, leading to cracks in the filler. I decided to install a brand new 3/4 inch subfloor and opted for laminate throughout the rest of the area.
The seams visible in the photos seem quite wide for filler. I’m not sure about the product you used. Based on my research over the past 40 years, filling seams and cracks on floors without a subfloor is typically best done with rope or ‘oakum’ due to the natural movement of the wood floor. The fillers you applied appear much lighter compared to what I’ve encountered. I also find that wider boards tend to have more movement. Perhaps embracing the cracks as part of the floor’s character could be a good approach. Are the floors tongue and groove?
Not that you asked, but maybe you’re overthinking it with the hyper focus? I believe once all the furniture is in and the house feels like home, the original flooring spacing adds to the character and charm of the property. I’m all for preserving original hardwood when possible.
I’m pretty confident that if there’s nothing underneath those, it’s the subfloor … not the floor that needs refinishing. By the way, you won’t be able to fill those gaps because there’s nothing underneath. Usually, people use sawdust from sanding mixed with wood glue to fill them in. Anything else you put in those spaces will either fall through the bottom or come out the top.