hardwood floor question over UFH

[glasshouse]

evening, we are thinking of having a solid hardwood floor(oak) over our proposed new UFH which is between joist with a dry mix covering the pipes up to the top of the joists.The joist c-to-c are 400 mm.The UFH supplier and wood flooring suppliers are a bit vague about the following ..Can the hardwood be secret nailed straight on to the joists?With no other material between?. If so is there a minimum thickness of board and is there a maximum width that we should be looking at? Any other major pitfalls we should watch out for?Any advice welcome, thanks

 

[WoodYouLike]

Hi glasshouse
Solid wood on UFH is not very recommendable. Wood-Engineered will be much better suited for the task. See here for more advice and methods for wood on UFH

 

[joe-90]

Timber is very insulating. Have you considered tiling?



joe

 

[glasshouse]

thanks for replies, WYL have looked at the site v.good info still a bit lost on whether engineered wood can span those joist c to c's and if they are t+g'd all 4 sides can the joints be between joists?and if they can be laid straight on to joists without an intermediate layer.?However the wider board is a good thing .Joe -90 it's for a living room and family room so the tiling option isn't really on with the little ones around.Any obvious downsides to engineered wood that I've not read about?

 

[WoodYouLike]

Glasshouse, if I understand correctly the screed will cover the UFH pipes and will be level with the joists? So in fact, the screed will also 'support' the floorboards. You can then either glue the floorboards completely to the screed and joists, or you can install the floor floating and use DPM and sound-insulation.
No known down-side to engineered boards, as long as you go for quality ones, without MDF/HDF backing.

 

[glasshouse]

Thanks WYL, the "screed" is only 25-35mm thick on celotex type insulation so isn't really structural. If installed as floating why would it need a DPM?Would the sound insulation start to affect the UFH 's output?With this in mind I would like to install the floor straight on to joist to minimize any air gaps affecting the UFH, am I right in assuming the end of the boards would have to be over the centre of joists?Sorry to be so vague it's a situation with no clear answer I feel. cheers

 

[WoodYouLike]

I misunderstood the 'structure' then.
Every board has to 'rest' (and nailed) on minimum 3 joists, doesn't mean every joint has to be on a joist. See here for more practical advice on installation methods

 

[glasshouse]

I see that the recommeneded joist gap is 30-35 cm I have 40 cm. Will this cause a problem do you think?Thanks

 

[WoodYouLike]

Not really in this situation. It would be more of a problem on joists above a ventilation area or upstairs.

 

[glasshouse]

Thanks WYL for your time and advice much appreciated, I 'm sure i'll be back on before long..