08-8021 - Laserfiche WebLink

Browse Search

'- Subsidence Investigation Pittman Residence - Zephyrhills, Florida son Project Number: 3017839 3.3 Relative Floor Elevation Contour Map The data for a relative floor elevation contour map were collected on February 13, 2008. The methods used to evaluate the floor configuration are described in Appendix A. The floor elevation map indicated that there was a total elevation difference of approximately 0.9 inches across the floor slab of the main living area of the residence. There was a radial slope of approximately 0.6 inches over a span of 10 feet recorded descending toward the north central portion of the northern wall of the structure. It is important to note that this slope corresponds to the general location of the depression encountered beneath the slab at the rear of the site. This correlation indicates that minor differential settlement has occurred at this portion of the structure. The floor slab of the garage was constructed 4.0 inches below the finished floor elevation (FFE) of the living area. The floor elevations in the garage have been adjusted to reflect this difference. The floor slab of the garage exhibited a slope of approximately 1.0 inch over a span of 20 feet descending toward the southeast comer of the garage. It should be noted that the floor slab of a garage would normally be sloped toward the garage door opening to allow proper drainage. Therefore, given that the garage floor does not slope toward the door opening and there is damage present in the garage, it is the opinion of SDU that the garage has experienced differential foundation movement. Figure 5 depicts the contour map showing the relative elevations of the floors. Where carpeting, wood, tile, or other floor coverings exist, corrections have been made to obtain the top of slab elevations. 3,4 Evaluation of Structural Damage The observed damage on the exterior and interior of the residence is consistent with either the direct result or the collateral effect of differential movement of the foundation. The direct result of differential movement of the foundation occurs when a portion of the structure is damaged directly due to a loss of support of underlying soils. The collateral effect occurs when stresses resulting from uneven foundation settlement are redistributed through the structure. Differential movement results in the cracking of concrete, masonry and drywall, and in some cases results in the sloping of the floor slab. See Section 2.0 "Geologic and Geotechnical Evaluation" for further discussion of deleterious soil conditions encountered at the site that may have initiated the differential movement of the foundation. 3.5 Summary of Structural Evaluation It is the professional opinion of SDU that the observed damage on the exterior and interior of the residence is consistent with either the direct result or the collateral effect of differential movement of the foundation. 3-2