Squeaks can be annoying but rarely do they indicate major problems. They usually occur when a board rubs against a nail or another board.
You can permanently fix your squeaky floor a few different ways. If you have hardwood floors you should first try to fix the problem from the bottom. Get a helper to stay in the house to step on the squeaky spots to help you locate them from under. When you find the exact spot of the squeak use a wood screw with a washer that will only reach half way into your surface floor to tighten it down in loose spots. You can also use small annular-ring finishing nails from the top after you have predrilled a hole.
If the squeak is between the joist and the floorboard you can lightly tap shims into the gaps to stop the noise. If there are big gapsÂ Â the joist and the sub-floor you can use a cleat to pull the flooring down tight. This will usually prevent noises at that contact point and on down the joist. It will also prevent bowing in the future.