Do you have a raised foundation? Easy ways to tell: Do you walk up the steps to get to your front door? Jump! You can hear you are on wood, not on the brunt force of concrete. Walk around the outside of your house and look for a crawl space. Once you have determined you have a wood subfloor you can start to plan your installation.
First, to start your new hardwood floor, make sure the earth underneath your house is covered in heavy plastic. This will ensure your floor doesn't respond as much to the moisture in the earth coming up into your hardwood floors. Then we check for level of the subfloor before we install it. Often the earth has settled and the subfloor is sagging over joists. If we solve the leveling issues with leveling compound you can no longer nail your floor, so you need to consider floating or glue-down installations. A combination of leveling compound and grinding high spots may be used, but we are limited in how far down the plywood we can grind. You might also want to consider the weight of leveling compound if you are trying to make up for large discrepancies. If you are filling a depth of more than an inch you might want to use plywood and feather it out with leveling compound. If you are able to nail down your hardwood, because you didn?t need leveling compound, then be sure to put building paper/?felt paper?, further blocking moisture transmission from the earth below.
Be sure to make sure the vents around the outside of your house are not blocked and you have adequate airflow under the house to ensure the future success of your new flooring.
If your foundation is concrete, then you won?t be able to nail your hardwood down, and you will need to decide between gluing and floating your hardwood flooring. Gluing is only an option if the hardwood is engineered; solid hardwood should not be glued down. The only exception is if it is small, narrow pieces, like parquet hardwood, or the manufacturer recommends gluing. In that case, follow all instructions of the manufacturer concerning glue options and procedures. Some hardwoods cannot be floated, so again the manufacturer's instructions MUST be followed. Consulting your hardwood professional is always recommended before purchasing any flooring.