I recently installed a floating bamboo floor.  It is an engineered floor that is 9/16" thick.  It is installed over a plywood subfloor on the second level of an apt building.  I let the boards sit in the space for 1 week prior to installation.  I put down the recommended foam vapor barrier and taped all seams.  Each board is 6'-3" X 7.5" it has a click joining system (glueless) along the 6'-3" seam and a standard tongue and grove along the 7.5" side.  I followed all manufactures guides for laying it. (ie never having seams closer than 20 inches, never have pieces shorter than 24" etc)
Over time the 7.5" T&G seams have started to separate slightly.  Anywhere from a hair line 1/32" to close to 1/8" gap.  The long clicking seams have stayed tight.  
I have already installed all of the trim so none of the board ends are exposed.  
Is there anyway to move these boards in place.  I though of putting a thin piece of rubber down and then placing a small section of 4x4 on it.  Then standing on the 4x4 and hitting the end with a mallot.  This worked ok but not that great at moving the boards back together.
Anyone have a better method?
Thank you,
Ryan
