1 – Let your wood acclimate in the room(s) it’s being installed. Two weeks is a pretty common guideline, although longer can be advised. Also, try not to let the wood acclimate during unusual weather or when “wet” trades are still working. Projects like real plaster, some painting, etc. can make the environment unusually humid. If you install that damp wood, it’s likely to shrink and crack when it dries out. 2 – Start with a really flat surface. I actually took a belt sander and smoothed out the seams/transitions in our 3/4″ plywood subfloor. Even slight lips at the edges where your subfloor meet up can make for unsightly bumps on your finished floor. A little extra prep work here goes a long way. 3 – Most installers recommend rosin paper or 15 lb roofing felt to underlay the flooring. Some applications require a membrane to keep moisture from below the subfloor away from the wood. Since our install was on a 2nd floor above other living space, I just used 15lb felt and butted the edges carefully before stapling them down. If you overlap the felt you can get a bump in your finished floor. The felt provides a little cushion between the wood and subfloor, which can help reduce squeaks and noise. 4 – The starting and finishing rows are the hardest. I started on the inside wall and worked my way to the outside wall. Make sure your first rows are parallel to the walls so you don’t wind up with slightly diagonal flooring and gaps. Generally you want to use your longest and straightest boards for the start. Depending on your board size, you likely won’t be able to use the floor nailer in the first couple runs. I face nailed the very first board (since the nails would be under the shoe moulding later. I then toe nailed the first and next couple boards before I could start swinging the nailer. I pre-drilled and used finish nails, followed by a nail set to countersink them. Pre-drilling helps avoid splitting. 5 – Leave an expansion gap around the floor. I left about 1/2″-3/4″ on the two long sides. I couldn’t leave a gap for some of the floor lengthwise since the boards were captured on both sides, but generally wood expands over the width of the boards more than the length. If you have the option, leave a gap for all sides, but make sure you have baseboards / shoe moulding that will cover the gap from view. Having an exposed gutter around your new floor probably wouldn’t look very good. 6 – Buy more wood than

Excerpt from:
Top 10 Things I Learned Installing Hardwood Flooring