Adding underfloor insulation to a 1920s house

[warmmfeet]

Hi, has anyone got recent experience in adding underfloor insulation to an old house?

We have floorboards over a cavity in the lounge and it's very cold and draft, even with the carpet on top.

Under floorboards is a large cavity, I've read about ways to insulate without damaging ventilation and causing mould problems as obviously is the concern.

Wondered if anyone had recent experience of this?

What did you use?
How effective is it?
How expensive

Any further advice etc!

TIA

Watching with interest, as I could have written every word of this!

There are a few ways you can tackle a job like this. You could cut a hole in the floor and go underneath and fit glass fibre type insulation between the joists and secure it with some kind of netting. This all depends on how much space you have underneath?

Or take all the floorboards up fit pir insulation boards between the joists and lay a new floor on top. You can seal any gaps with expanding foam. This is the best way but would be more expensive.

Like this.