Replacing timer floor with concrete

[Lounge About]

Hello!

After sanding the living room floor last summer it is now evident that the winter months will have to spent with big thick socks unless something is done with the floor and I wanted to ask your opinion on one option.

There is only a small void under the joists not enough to crawl under so most of the boards would have to be lifted just to insulate it.

So I was thinking why not rip the whole lot out and replace with hard-core, DPM, concrete slab, insulation, then underfloor heating (wet) in screed.

Easy?

 

[stuart45]

Easy if you know what you are doing. More work than lifting the boards and sticking some celotex between the joists. Depends on your budget and skills.

 

[Lounge About]

Are there any reasons not to replace a timer suspended floor with concrete?

I like to think i'm a competent DIY'er, 2 rooms would be done so probably need 15 ton of hardcore, 3 cubic meters of concrete, the underfloor heating won't be cheap (I got 200m of pipe for doing some electrics for a friend), about 8 sheets of 100mm insulation and probably just shy of 2 cubic meters of screed.

 

[stuart45]

The main thing would be the cost. DIY is just your time. Some people do prefer timber floors though, and also if your walls don't have a DPC, there is a chance that underfloor moisture could be sent up the walls, once it can't escape through the DPM.

 

[Lounge About]

Damp was my main concern, the house was built 150 years ago so probably has no damp proofing. I can see another forum thread is just round the corner

 

[stuart45]

Limecrete is an option for floors like this. Look on Mike Wye's site.

 

[freddiemercurystwin]

Assuming your joists are sound and ventilation to the void is adequate ripping up your timber floor and replacing with concrete is a complete waste of time and money and you will not end up with a warmer floor than just insulating between the joists.

 

[Lounge About]

if just insulating between joists is as warm as underfloor heating why does anyone bother with underfloor heating?

 

[stuart45]

if just insulating between joists is as warm as underfloor heating why does anyone bother with underfloor heating?

An insulated timber floor is as good as a concrete one without the underfloor heating. With U/F heating the floor will be warmer.

 

[Lounge About]

Are you trying to say; insulate the timber floor using battens on the joists and fit underfloor heating on top of this (notching the joists for the pipe at each end) and covering with screed up to the level of the joists?

 

[stuart45]

That's one of the method used for U/F heating on a suspended timber floor.

 

[Lounge About]

Is it the method you would use?

Is the screed a dry mix?

 

[stuart45]

The screed is a dryish lightweight mix. For an older property this method is probably as good as any.

 

[Lounge About]

Cheers for that, it will be much quicker too

 

[Nige F]

Limecrete is an option for floors like this. Look on Mike Wye's site.

I saw limecrete used on a Grand Design programme - not that clever IMHO . Also if you convert wooden to solid you`ve got to provide conduits for ventilating the existing wood floors that might be isolated by the concrete one