Foundation Contractor Wall Survey
The CFA Questionnaire received an excellent return with 53 of our contractor members responding. It will take quite some time to sort through all of the results but some of the easier to-tabulate summaries are listed below. These are based on the 53 returned questionnaires – not on the full membership.
- Number of basements poured in 2002: 12,467
- Number of basements in past 10 years: 112,624
- Strength of concrete (walls): 2500 psi – 1; 3000 psi – 29; 3500 psi – 18; 4000 psi – 10 (note: some respondents use more than one strength, depending on the project).
- Use horizontal steel: 47 – yes; 5 – no (note: the number and location of reinforcement bars varied)
- Number of wall problems from lateral loading: Approx 120
- Number of above problems where top bracing or deck was not in place: approx 114
- Most frequent cause of failure: (1) Heavy machinery next to foundation; (2) Excessive soil pressure from soil/water
- Number of above listed problems that occurred after two weeks of pouring: 11
A full report of this information plus the cold weather portion of the survey will be published in a future edition of the newsletter.