Hardboard manufacturers have very clear specifications regarding both aspects, but many contractors disregard this vital information. Most hardboard is warranted against product defect for 20-25 years. Obviously the ideal situation is to monitor the installation and have deficiencies corrected as they occur. This is where you friendly home inspector can be of assistance. Again, a qualified inspector can identify deficiencies and any related damage, and propose remedial action needed.
Moisture is the enemy of hardboard siding.
Almost all installation deficiencies allow exposure to moisture, resulting in absorption and subsequent degradation of the material. Nail heads should be driven to where they butt tight to the siding or are flush with the siding face. The siding then swells out beyond the nail, creating more access for moisture and the situation goes from bad to worse. Most builders spray paint a house. Unfortunately this technique results in less paint applied than the specifications require.