A hardwood installation is an expensive and major home addition. You want the job to be completed by a quality installer to ensure your investment is completed exactly the way you would expect.
Hardwood must be delivered 3 days before teh installation to adjust to the climate and temperature of the house. Some prep work to the subfloor and then felt has to be rolled out for noise reduction A quarter inch expansion gap left on all sides then sealed with quarterround.
Engineered hardwood needs all the same but it is glued down