Suspended timber floor - replace with concrete?

BoardsMember

Hi All. At the early stages of doing a refurb job on our house, to include improving insulation, re-wire and an extension.

It's a 1920's house with original suspended wooden floors. The only really effective way to insulate properly while keeping suspended timber floors appears to be to rip them up, insulate between the joists, membrane on top, tape, then boards back down. These would have to be new boards as taking them up will make sh1t of them. I don't think there is crawl space to do without ripping them up.

The alternative is to fill the cavity with stones then pour concrete, and screed and put in underfloor heating. With the underfloor heating option, we'd probably still go with boards in sitting room, albeit they'd have to be the right type.

As we enter into a cold stretch, this option is increasingly appealing to me. I've asked a QS to price up the two options. Just wondering has anyone made this change? I know the running costs would be slightly higher with uf heating (downstairs only), and we'd need to be sure we have a good builder/plumber to ensure good level of floor insulation. Apart from that, I wonder if this is considered a sensible option.

BryanF

Damp specialist or site investigation required by experienced arch tech or eng

Insulating the timber floor may work out a little cheaper but, opening up required to confirm method mad achieving

> continuous insulation
>air-tightness
> extent of vents sub floor
> rotten timber once opening up
> heating system routes, water, electricity etc

BoardsMember

Hi BryanF, thanks for answering.

How "open" would the floors need to be investigate properly? Could it be done definitively pre tender so that I know what I am dealing with, and know which direction to go in the tender?

I'm not sure I understand this bit "....mad achieving" and the list of points after that....some seem like benefits of doing the job, some seem like criteria that might determine whether to do the job. If you have the time could you explain please?

Thanks.

BryanF

BoardsMember wrote: »

Hi BryanF, thanks for answering.

How "open" would the floors need to be investigate properly? Could it be done definitively pre tender so that I know what I am dealing with, and know which direction to go in the tender?

I'm not sure I understand this bit "....mad achieving" and the list of points after that....some seem like benefits of doing the job, some seem like criteria that might determine whether to do the job. If you have the time could you explain please?

Thanks.

Mad 'of' achieving

Creteria a good arch tech would consider.

I went suspended timber floor route - it took a lot of time effort and it's not perfect as I have subfloor vents letting cold air into the subfloor/rising walls.

BoardsMember

Thanks for the info, much appreciated

tedimc

If it's of any help; I had a suspended timber floor over our basement.

Some joists had some rot, so we removed the joists and replaced them with concrete T-beams. Between the t-beams we then fitted an insulated block. I put UFH pipes down then and 100mm of concrete screed on top.

If you had the height, you could just go with concrete block infill's and plenty of insulation over that.

Happy with it so far.