If the locking joint is coming apart then just try kicking the board so the joint locks together again. If both boards are starting to lift but the joint looks OK it may be that it has expanded. Remove the beading from around the edge of the room and check that you still have an expansion gap up to the skirting. If the floor expands and touches the skirting then it has no where else to go exept upwards. This is caused by damp, a water leak or cleaning with a wet mop.
Trevor, January 2009
