Cavity wall insulationn with wooden floors

Confused_Jo

I had the Energy Efficiency people ccome to give a quote a year ago.
Was cheaper for me to to the attic myself with buy 2 get 3rd free at Wickes offer.
I also asked about cavity wall insulation but he said as we had wooden floors which are quite close to the ground then they couldn't guarantee the work in case it caused damp.
Is this correct or a load of old twaddle?
The partner house has had theirs done a couple of years ago but have a much larger distance below their windows that we do.

We live in a 1930's semi. Wooden floorboards in the living room, dining room,pantry and the hall. The kitchen is concrete. the ground outside is almost level with the floorboards.
How likely would it be that there would be problems?
What would anyone recommend and has any one lese had experience of this?

Thanks
Jo