On Feb 11, 9:04*pm, Mikepier wrote:
Lately I've noticed a problem in my living room floor in that the wood
is buckling or crowning a bit with gaps between the boards directly
above where there is an HVAC duct running underneath between the floor
joists( about 10 feet length total). I think it has gotten worse this
past year because recently I finished my basement and closed the
ceiling with sheetrock, so I'm guessing all the heat from the duct is
concentrated upward towards the floor, although I thought wood shrinks
when its warm and dry instead of expand. Is there an easy fix for
this? Can it be hammered down with a 2X4 and hammer?

Does your hvac system have a humidifier in it? If so and the metal
boot ends at the subfloor then you may have moist air infiltrating the
floor area. Enclosing the space below may have kept the air in closer
proximity to the wood for longer. But enclosing the space below may
just be a coincidence. You can use hvac mastic to seal any gaps. You
might be able to raise the metal boot as well. If you don't have a
humidifier then I'm a bit surprised.

In most cases crowning at the joints is caused by moisture. I would
not expect heat alone to do anything. Typically in the winter wood
floors shrink and have more pronounced gaps. Unfortunately after it
drys the crowning may remain. Unless it is really bad you probably
just want to live with. The only fix is to sand the floor flat again
with a belt sander and refinish.