Floorboards over wet underfloor system - wax or varnish?

[blissbaby]

We are currently installing wet underfloor heating system, and once done we plan to reinstate the original pitch pine floorboards.
We have heard various - and many!! - opinions as to whether timber floorboards would be detrimental to the efficiency of the system, but as we can't afford to replace all flooring, we are going to replace the floorboards anyway.
My dilemma is this - a joiner said that the wood will warp if we are going to varnish the floorboards (as the varnish will make the wood inflexible on the varnished side). I asked about wax - thinking that this would be leave the wood more flexible... but he wasn't sure about my theory!
What do people think?
I'd appreciate any suggestions or opinions.
Thanks!
BB


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[tall_tone]

My dilemma is this - a joiner said that the wood will warp if we are going to varnish the floorboards (as the varnish will make the wood inflexible on the varnished side). I asked about wax - thinking that this would be leave the wood more flexible... but he wasn't sure about my theory!
What do people think?
I'd appreciate any suggestions or opinions.
Thanks!
BB

Most modern waterbased lacquer (varnish) are flexible and mircoporus (breathable). They have the same chance of holding back wood expansion as I do of competing in the 2012 Olympics.
Old solvent lacquers were less breathable and less flexible. but had a tendency to crack or craze after a period of wood expansion or contraction. They would never hold back wood expansion.

If the wood warps it is down to moisture content in the wood.

As for wax, it would come down to which finish you prefer the look of.

 

[blissbaby]

Thanks for the advice... and good luck in your Olympian challenge!
BB


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[mac391]

Your joiner is technically correct !!