Insulating under floorboards - has anyone done it?

[daisie4]

Hi, We'd like to insulate under the floorboards in our sitting room as it tends to get really cold in there but am having real trouble finding out how.

We've got no access from underneath as there's a cellar below with a lathe and plaster ceiling, so we'd have to lift the boards. Is there a way of doing it so we only have to lift every few for example with loose filling? Or is something like Kingspan the way to go, in which case is the only way to get it in by lifting the whole floor and removing skirting? And should we get someone in to do it?

Any help would be much appreciated!

Beg your pardon, sleeper wall in this context. It's a little wall giving your joists extra support in the middle of the room.

Ah, concrete at the back. Um, this is the sort of house that gets probs, iiuc. You could speak to a surveyor and get a professional opinion. But my (probably very flawed judgement) would be not to put anything at all under the boards - the ventilation is so poor any further restriction could be the death of them.

That was my gut-feeling too It's a shame as the sitting room is a really lovely room, but for half of the year it is too cold to sit in after sundown. (I am the type to be found under a blanket each evening during summer, and a 15 tog feather duvet all year round )

underlay... fit with the silverside up using short slabing nails, it can be bought very cheaply from B&/homebase. cgi.ebay.co.uk/25M2-LAMINATE-FLOOR-UNDERLAY-FOIL-DAMP-MEMBRANE-/150568738932?pt=UK_Flooring&hash=item230e98a074

Thank you concul

Hi, Sorry, probably sounding a bit slow now, but just to recap, can I insulate under the floorboards, or am am going to cause damp problems by doing it? Doesn't heat travel up so cellar wouldn't be as affected as roof? Also cellar has a ceiling so drafts don't tend to come up. Actually not sure where the cold is coming from if there are no airbricks? Would it be two external walls? But if it is why does floor feel cold, and neighbours had same problem, which was resolved when carpet put down (we want sanded floorboards)?

Hi Daisie,my floors fine.The travertine is really good for not showing the dirt i've found.I still havn't got round to sticking the second coat of lithofin on in the kitchen so i probably need to inspect the grouting carefully for stains.However all the stains on the tiles wipe off.I have had a succession of painters [tiler is still here] and so have had large amounts of foot traffic and dirt/dust to contend with and so can't be too obsessional .Interesting concept that 'patina development'.Do you think he's saying that once several stains happen you don't notice the original ones?.Sorry, maybe its just me being very cynical.

Maybe you'll get damp. Sorry, can't be sure.

If I were in your situation, I'd spend the next 6 months testing walls & ceiling with a damp meter. If there's no damp, I'd risk the insulation. (But keep the drafty windows for ventilation.)

If it's slightly damp, I might still risk it but keep monitoring and be prepared to haul all the insulation out again if you start getting a problem.

Idea: start a House Log Book. Note all significant works, draw diagrams of pipework and wiring when you take floors up. And hand it on to the next owners, so they can carry on the monitoring and know which boards to take up to get to what.

Daisie our floor has developed a patina already.Tiler was commenting on the fact.He has just laid more travertine in the dining extension and it is noticably lighter.He says the floor becomes polished with use and it changes the look of it.Our floor has developed a patina in a few weeks due to lots of workman plus plaster/wood and furniture landing on it!.