Communicate-
- That you are the professional, the "go-to" person for direction and advice on wood flooring and flooring issues.
- You will follow recommended industry practices.
- Product selection determines substrate requirements.
- Wood flooring requires an established environment near occupied conditions.

Accepting similar site conditions can make you the responsible party for later problems since they don't follow recommended practices.
You Will-
- Check job site conditions before flooring delivery and installation.
- Advise on corrective options, if conditions are not correct.
- Install according to manufacturer's recommendations with attention to detail.
- Check product both before and during installation for acceptance.
A proper subflooring must be in place (see "Proper Subflooring for Mechanically Fastened Wood Flooring" FCI, October ‘04). Impress on the builder that wood flooring is a premium product and thus requires a better than "to code" flooring system or a "code plus" system. If the system simply meets code, the likely result will be call backs, from such issues as noises, movement, gaps, and related finishing issues. The time taken for just addressing a call back related to the minimum system will most likely cost more than the code plus upgrade for wood flooring.

Show you are a professional and have a moisture meter that you actually use.
You should know the typical conditions required for your area and report the conditions you expect to observe. If they are found to be different from the expected, give options for corrective action. Actions such as: using fans and dehumidifiers to reduce high moisture conditions, repairing/refastening subflooring, making the subflooring flat, and completing wet work installation. Also, you should report that changing environmental conditions can not be accomplished over-night they can take days or even weeks depending on conditions.

Showing this type of detail is not an acceptable practice.
From this conversation you have also pointed out some of the builder responsibilities. The builder should identify the specific flooring materials and provide the recommended subflooring. Proper site environmental conditions should be established, that is: the building is dry with all windows and doors in place and installed properly, wet work (including dry wall taping) is completed, and additional work to be completed will not harm the flooring. You have mentioned layout and this should be reviewed with each installation to determine flooring direction particularly with joist construction. Solid unidirectional flooring should be installed perpendicular to joist supports. If this is not the desired direction then builder responsibility is to provide additional support.
The builder calls on a Friday and has to have the flooring installed next week. When you visit the site, the great room stone wall and fire place are not in. You check the subflooring and get numerous readings of 15-16 percent moisture in the subflooring of rooms designated for wood flooring and 18-20 percent moisture at the entry and rear doorway to the future deck. There is water standing under the house.
What to do? Report the conditions to the builder. Suggest heat (if in winter use electric heaters, as kerosene heaters produce water as a product of combustion) and fans to produce significant air movement. Establish a specific moisture target, say, 12-14 percent moisture in all areas of the subflooring. Also report the higher conditions at doorways and the need to check for gaps and water intrusion. Suggest the crawl space or basement be pumped dry and ground cover installed with a dehumidifier operating. Document the visit with photos and acknowledge to the builder with a note or by email. Report that the conditions presented will likely produce cupping followed by gaps and crowning for site finished flooring.
You are fulfilling your commitment by giving sound advice. If this builder is a major customer he knows your reputation and should proceed with the suggestions. If time is really critical you may decide to proceed with installation only if the active moisture reduction is continued to help minimize performance issues. If no effort is started to reduce the moisture and you install the flooring you will likely become the responsible party to fix the floor. The fix will probably cost you much more than any profit from the original floor. You are the professional, if you accepted adverse conditions this will be your work not the builder's.

You are the last inspector and should not install obviously defective boards.
When you visit the site, your purpose is not to establish blame but to find a solution to the issue. Visiting with the builder shows you are both concerned and attentive to the issue. At the site review the issue with the consumer and repeat in your own words so that you understand. As the professional address the issue by collecting data. This involves noting your specific observations, moisture readings as necessary, and measurements. Ask what it would take to satisfy the complaint. Set a specific time to review your conclusions and remediation with the consumer. Most of the issues will not be settled at the site. You will have to review the data to make an informed recommendation for the fix. Keep the builder in the loop and respond promptly. This shows that you are concerned about customer service to the builder and the consumer. If the situation cannot be settled or you are unable to determine a solution, call for help from the distributor, manufacturer, or association. When all else fails, it may be necessary to call on a NOFMA- Certified Wood Flooring Inspector to review the case as an unbiased party. This should be the last resort.