Massive pile of sawdust under floorboards

[bebeboeuf]

we are fixing up a few areas of our Victorian house. The floor is timber on joists over a void.

DH lifted a board and I happened to see that he has swept a huge amount of sawdust into the floor void rather than sweep it and bin it. He doesn’t see a problem with this

Is there any issues this could cause down the line if it is left?

Well, it's basically kindling and could ignite rapidly in case of fire. Might be ready-made nesting for vermin?

This is common in Victorian houses, provides great sound insulation, it is not a great fire risk.

Absolute fire risk. It will burn far faster and quicker than a piece of timber.

If it's in the ground floor void that is damp and would provide an ideal place for rot. The ground floor void must be clear of all organic matter as dry rot can seed from an area on the ground and then grow to other timber in the area.
For the sake of 5 minutes work, i would clear the void as much as possible, especial in an old house like yours.

Thanks for advice - I have been told by DH that he has cleaned the void!