Do the gaps need filling?
This is down to personal choice. A gap-filled floor looks even and is pleasing to the eye. Filling gaps does help to prevent draughts (especially on the ground floor) and the build up of dust. As the floor is also tightened, timber movement is minimised.
Traditional methods of gap filling include:
* resin mix - mostly used floors with lots of fine gaps, such as parquet and mosaic. Dust from the floor is mixed with a resin and applied to the gaps with a filling knife.
* wooden strips - solid fillets of reclaimed pine and other timbers are glued and forced into the gaps, being chiselled back before sanding flat.