Can I install hardwood flooring on wood joists systems with other than 16″ on center spacing?
NOFMA’s subfloor tests (1992) concluded that good performance of 3/4″ thick strip and plank flooring could be obtained with 16″ on center spacing and proper subflooring, see NOFMA’s Installing Hardwood Flooring. Today, with “Engineered Joists and Trusses,” spans and spacing are often encountered which are longer and wider than with the solid wood members previously tested. Even though these systems are properly engineered for loads encountered, more deflection along the length of the span and across the spacing is also often encountered. 3/4″ thick hardwood flooring can be installed over these properly engineered systems, but the expected “in use: performance of the flooring may suffer. The added movement may influence the flooring to have more than expected creaking and cracking between strips. Also, as pieces flex and move against each other, surface finishes may be stressed and show whitening along edges. These possible results most often should be noted to the end user. Comparable
