Dust from floor sanding falling onto insulation/membrane

hatt55

My second post of the morning!

I'm considering having floorboards sanded in a living room. They are Victorian but seem to have had a brown, slightly translucent varnish applied at some point in the past. The is is now spattered with paint and plaster from previous decorating.

The boards have just been lifted and relayed to insulate, which means there is a membrane between the floorboards and the joists. This was installed, amongst other reasons, with a view to stopping dust from the insulation coming upwards. I've now realised that if the floor are sanded the membrane will also trap any dust that comes from above!

I know the professionals use almost dust free sanding methods, but am a little concerned with the thought of some dust being trapped through the cracks between the boards, especially if the wood has historic varnish is unknown origin and, potentially, splodges of lead paint.

This is one of my 4am internet deep-dives so just wondering what people's experience of 'dust free' sanding is, and whether anyone with a similar membrane build up beneath the floorboards can account for how much dust gets trapped?

When I think of the number of people that must sand floors that have previously been varnished, I do lean towards the conclusion that I am over thinking this. Its a risky business looking at websites form the US where it seems there is major panic over lead in paint etc., but I don't think varnish is so risky for that.

Eldi_Dos

If it is worrying you and you want a cheap DIY fix, get suitable thickness natural fibre string and caulk between the floorboards before sanding.