Last spring I installed 3/4" Myrtle flooring in our house. The flooring was nailed down with 1.75" staples over 15# felt and about 1" of OSB subfloor.

http://www.greenmtwood.com/california-b ... oring.html

This summer I installed a radiant system under the floors between the joist using a thermofin heat transfer plates

http://radiantengineering.com/productsthermofin/

Our boiler operates on a heating curve and has been pumping some pretty hot water under the floors (140 f) now that its cold and wintery. Last night's low was about 8f.

We have a few area rugs over our flooring and the Myrtle has gotten very hot in these areas since they are insulated by the rugs. I can see the gaps between these boards have opened up more than in other areas. I think I am cooking the flooring in the areas where there are rugs.

I am going to back off the heating curve and make sure these areas under the rugs stay a lot cooler.

Will these gaps close up with time now that I have lowered the heating curve? Should I get a humidifier and try to get some moisture back in the floors? Have I buggered the installation and will the floors be affected indefinitely?

Thanks in advance..

-j

I have always been told to never let a radiant heat get over 80deg if you want to keep your floor from shrinking/drying out. Honestly I never have seen a myrtle wood floor and know nothing of the specie. General rule of thumb is you never know for sure if its going to go back, depends how severe the cracks are and how long they have been there. Wood floors do have a memory and will close backup once the conditions return to "normal" in many cases. Just cut down that floor heat to keep it from getting so hot and I think you will see some improvement, probably be next spring before it goes back like it was before the heat.