How to fill substantial gaps in wooden floor?

[manintheboxtj]

Searched but could only find solutions to minor gaps. 

I'm looking to fill these significant gaps in my wooden floor. Some are so deep that you can see the outside, others allow me to fit a credit card all the way down. 

I assume a product like Selleys No More Gaps would just fall through?

Thanks! 

[MitchellMc]

Welcome to the Bunnings Workshop community @manintheboxtj. It's wonderful to have you join us, and many thanks for your question about filling gaps in timber.

To fill substantial gaps in your wooden floor, you can use wood filler, which is designed for this type of repair. However, for deeper gaps, it’s often helpful to first insert a foam filler rod into the gap, just below the surface. These rods provide backing and support, ensuring the wood filler doesn’t simply fall through. Once the foam rod is in place, apply the wood filler over the top, pressing it firmly into the gap. Allow the filler to dry completely before sanding it smooth and, if necessary, staining or painting to match the surrounding wood. 

Please let me know if you have any questions.

Mitchell