American Society of Home Inspectors (ASHI^® ), identified the most common home problems, many water related.(source:ASHI^® )

1. Improper Surface Grading and Drainage.

   By far the most frequent problem. It is responsible for the most common household aggravations, including water penetration into the basement or crawlspace. All basements will eventually leak.

2. Improper Electrical Wiring.

   A number of respondents found this to be a significance defect. This includes such situations as insufficient electrical service, inadequate overload protection, and amateur often dangerous) wiring connections.

3. Roof Damage

   Ranked third, leaking roofs are a frequent problem. This is caused by old or damaged shingles or improper flashing and drainage.

4. Heating Systems.

   Defect items in this category include broken or malfunctioning controls, blocked chimneys, and unsafe exhaust disposal.

5. Poor Overall Maintenance.

   A common problem with all homeowners. Signs of poor maintenance include cracked, peeling or dirty painted surfaces; crumbling masonry; makeshift wiring or plumbing; and broken fixtures and appliances.

6. Structurally Related Problems.

   As a result of problems in one or more other categories, damage is sustained by such structural components as foundation walls, floor joists, rafters and window and door headers.

7. Plumbing.

   Though not ranked as a number one problem, plumbing defects still rank high. This includes the existence of old or incompatible piping materials, as well as faulty fixtures and waste lines.

8. Exteriors.

   Flaws in this category, such as windows, doors and wall surfaces, rarely have structural significance but may pose discomfort to the occupants due to water and air penetration. The most common culprits are inadequate caulking and/or weather-stripping.

9. Poor Ventilation.

   In an effort to save energy, many homeowners have "oversealed" their homes, resulting in excessive interior moisture. Significant moisture can lead to rotting and failure of both the structural and non-structural elements.

10. Miscellaneous.

    This category includes interior components (often cosmetic in nature) which were so infrequent that they did not rank individually in the survey.