Hi. I am installing unfinished maple 3/4 x 3 1/4 #2 & btr over 3/4 t&g ply subfloor. Wife and I are carpenter and electrician very well skilled in construction. House has had constent 68 deg for over two years. Subfloor flat = - 1/16" in any 10 ft. Zero squeeks in joists or plywood. and has a MC of 8 to 8.5%. My maple flooring has acclimated in the house for 2 months stacked flat and stickered. It has a MC of 6.5 %. To me this seems like perfect conditions. I used aquabar paper between hardwood and subflroor. I installed a 13x13 room last weekend using 2" cleats with an air nailer. Got nice tight joints and all, nails spaced 4 to 6" and 2" from ends. floor looked great. came back a week later. and walked across floor and it crackles every place I walk the first time. the more I walk on it the less it talks to me. Am I srewing something up here or do my maple floor just miss me? Outside air temp did drop into the 20s this week. inside is maintained at 68 deg F. House has forced air heat ducted underfloor to rooms. No radiant heat in floor. Should this Squeek at this stage? will sanding a finish change the situation? And thoughts from the pros? I would be forever greatful. Thanks Rick.