HI JIM, I AGREE TOTALLY, HOW DO I SOLVE MY PROBLEM, SOMEONE POSTED THAT THEY USE PASTE MIXED WIT SAW DUST AND SAYS THE SAME THING AS YOU DO BUT WHAT KIND OF PASTE ASKED BUT NO RESPONSE YET, IF YOU HAVE A SUGESTION PLEASE LET ME KNOW ALSO THIS BUILD MAKES IT DOUBALLY A PROBLEM AS IT NEEDS IT BOTH SIDES INTERIOR AND EXTERIOR IF I CA FIND A SOLUTION TO THE GAP/FILLER PROBLEM IT WOULD BE GREAT, I KNOW THE BEST THING IS TO GET THE PLANKS AS TIGHT AS I CAN BUT I KNOW THERE WILL GAPS, LET ME HERE. GOD BLESS STAY SAFE Don