I have installed 1/2" engineered maple flooring (model brand) and I noticed a couple of places that make noise when walked on. The flooring was stapled down using 1 1/2" 18 gauge crown staples with a bostich stapler. The first area installed was stapled approx every 4-6" as per install instructions. The next area I did I stapled every 2-3" b/c I noticed some noises in the first area the flooring was installed. The floor is better where I stapled closer together. When inspecting the noisey area, I discovered the noise is caused from parallel boards rubbing on each other. The sub floor is secure and has no movement/squeaks. Is this normal and do all hardwood floors eventually make noise? Wont the staples holding down the flooring eventually loosen over time and cause movement/noises?

I've never heard of a perfectly silent wood floor but that said, you could have a slight milling issue. If your manufacturer states the floor can be glued, floated and nailed then they mill in some slop.

This question always reminds me of the book I read about the Japanese Emperors and how they constructed the wood floors in the temples to squeak on purpose. They did this so that the Ninja could not sneak in down the hallways so easily without alarming the guards. True story swear to Alah.

I have some noise in my hallway, but I don't care cus then I can hear the teenager if he is trying to sneak out of the house. Then the dogs also hear it and start barking. No one will be sneaking down my hallway anytime soon.

The floor can be stapled, nailed or glued down. I thought it might be because there might be some play between the tounge and grooves. I purchased the highr priced engineered floor b/c I didnt want squeaks. Would a glued down floor be quieter/less noises than a stapled down floor because the flooring would be held down by the entire bottom of the board and not just by the staples through the tongue?

How flat is your underlayment and what is the underlayment or subfloor made of? Then you could have had a slightly bowed plank that did not seat down all the way as well. Those smaller staplers cannot pull down the planks as tight as the big guns can. It may stop squeaking later..

If you staple to close you risk splitting the tongue, then your going to have some severe squeaks.

The subfloor is 5/8" plywood. I installed anothe 3/8" plywood on top to have my finished floor height level with exixting tiled floors. I sanded all the high spots to try to get the subfloor as level as possible. The subfloor was tight and didnt have any squeaks. The noise is definately coming from the engineered flooring boards rubbing on each other.

How long has the floor been down? Did you notice any tounge splitting when you were installing. If the boards are rubbing they have some play in them somewhere. the t&g might be a little loose if they have dried out some. Or they are loose milled like someone mentioned before. A floors T&g should go together snug but not tight. Its not good if its was so loose that you have vertical movement after its nailed up.