Hardwood:
Here are some guidelines from the NWFA to better help you understand the installation process.
Subfloors must be flat:
3/16” in a 10-foot radius.If the slab or wood subfloor is out of specification, consider grinding, floating or both. Many high spots can be removed by grinding, depressions can be filled with approved patching compounds, and slabs also can be flattened.
Subfloor moisture test should be performed on both concrete and wood substrates:
A wood subfloor can be tested by a pin meter and the readings should be no more than 14%. Most manufactures want the concrete to be tested for moisture emissions. This test is done by ASTM F1869–Standard Test Method for Measuring Moisture Vapor Emission Rate of Concrete Subfloor
using Anhydrous Calcium Chloride and readings typically should be no more than 3 pounds in 1000sf within 24 hours.Wall to Wall Flooring Specialist will not warrant an installation unless these requirements are met.
There is much more information on installation and sand and finish of solid and engineered wood floors. We will send you more information at your request.