Nashua, NH Resident Looks for Advice Hardwood flooring is best installed in an area with controlled humidity levels that range from 30 to 50 percent. High and fluctuating humidity levels can cause the wood to expand and contract over time. Once installed, this can lead to buckling and warpage as the floor boards change their size and shift. This contraction can also cause the floor boards to crack and separate from one another. A homeowner in Nashua was looking to…