Stage 2 Option 'A':
Gap filling /up to 5mm/
If you have decided to have the gaps filled this is the next stage: The gaps can either be filled using a mix of resin mixed with saw dust.

Stage 2 Option 'B':
Gap filling /5-12mm/
The second method is to insert and glue wood slivers between the gaps in your floorboards. These are then sanded level in stage 3.
