Cost insulating floor

[oljkup789]

Just trying to gage how much it will cost for us to insulate the floor. We're in London in a Victorian conversion ground floor flat which is approx. 70m2. If you have recently insulated your downstairs, how much did it cost? We cant insulate the walls as they are single bricks, so the floor seems to be the next best thing. But not sure of the costs.

Depends if joist or screed flooring currently? Latter will be considerably more as this will need drilling out and insulating underneath

If you’re doing the work yourself between £30 - £60 per 1.88 meters squared depending on what thickness and type of insulation you are going for. I used 100mm thick Rockwool acoustic which I secured under the floor using chicken wire. If you’re paying someone it is a how long is a piece of string question. As per the debate in the other thread about pulling up flooring:

1. how much prep work is the person going to have to do? Will the room be cleared with the carpet up and everything dust sheet covered or are they going to have to move your grand piano and three piece suit upstairs?

2. how are the current floorboards secured? Is it nailed down (likely) or tongue and groove with glue?

3. what condition are the current boards in? Are most / all going to need replacing?

4. are the joists in good condition or will they need replacing?

5. what is going down ontop of the newly insulated floor and how much of a problem will this be? Will you need skirting and sockets raising or lowering?

6. what else might be found down there? Will there be a load of rubble that needs clearing out of the cavity to allow for insulation (most probably yes)

7. is there an old fire place hearth that will need drilling out in order to get a new joist over the top and put insulation in so as not to have a cold patch and negate the reason for doing this - we have a Victorian terrace and I had to use a breaker drill to remove this - noise and mess ++ but would have been pointless to leave and not insulate.

Took me maybe 3 long weekends to do just our front room of 4m squared but obviously working alone. Just to get access under the floor in an entire house will be a major undertaking even with extra hands. Then add in all of the above and I don’t think anyone can give you a figure other than this is what we paid last year for x,y,z or I would guess this.

using somewhere in the middle cost wise insulation I’d guess about £40 per 1.88 meters squared = £1500 insulation material. Another £500 for wood, screws etc, and then ?? Whatever else you need to have done that they find. Then how long to clear all the flooring in your flat and ? Storage / dust sheet. I’d be amazed if you got change from £10k if you want my vote.

@NonmagicMike see I know nothing about any of this. Very useful to have this spelt out. At the moment, there are bare floorboards but with small gaps in the middle which I guess need insulation and something on top.

No worries. No, the insulation goes under the floorboards so you will need to have them all pulled up and then the insulation applied and then all replaced or repaired and put down. All your possessions will need to be moved about to accommodate this. It will be a huge job to do the whole flat depending on what you have in there. Assuming there are going to be kitchen cabinets and bathroom tiles as an example that would all need to be pulled up unless you have a good crawl space underneath for someone to access?

There’s no way anyone can estimate any costs without seeing the job, 70 m2 just gives a scale of the work there are too many variables , type of insulation? , taking floor up or working underneath? And so on……