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Subsidence lnvE;stigation SDII Project Number•3023547 Quiros-Martin4;z Residence-Zephyrhills, Florida redistributed through the structure resulting in hairline cracking of the drywall in the ceilings and interior wall��, Locations that are particularly susceptible are above windows, doorways and openings, at or near changes in geometry of the framing, and at or near abrupt changes or corners of a drywal] �;�anel. These separations and cracking resulting from minor differential foundation movement, long term deflection, and post-construction settlement have no bearing on the structural inte;rity of the structure. The cracks ol_�served in the floor tile within the structure are consistent with movement (both horizontal and vertical) along concrete shrinkage cracks and construction or control joints in the slab beneath the tile that have been aggravated by thermal expansion and contraction, additional drying shrink��ge of the slab, or minor differential settlement of the slab. The movement along these types oi'joints and concrete cracks can propagate up to the floor tile. According to the American N��tional Standard Specifications for the Installation of Ceramic Tile, proper installation of ceramic tile involves using an isolation membrane between the floor tile and the concrete slab c�ver any existing cracks. Also, movement joints should be placed over joints in the concrete slab. The observed ��racking on the exterior of the structure is consistent with materials shrinkage of the masonry aiid/or stucco and minor differential foundation movement. The effects of thermal stress have further exacerbated the exterior cracks. Material shrinkage cracks form when the wall is constructed, though may not be visible for some time afterward. The width of these cracks is also influencecj!.by thermal stress caused by temperature changes, which cause the wall to expand and contract. 1VIaterial shrinkage cracks are commonly found in residential construction and typically oceur� at those locations in which the wall is considered to be the most susceptible to cracking, such as at window openings and corners. The degree of movement associated with thermal stress is a fiinction of the building materials, the length of the wall, and the amount of temperature cl��ange. Minor differential movement of the foundation appears to have further aggravated thi.; damage. See Section 2.0 "Geologic and Geotechnical Evaluation" for further discussion of ;�oil conditions encountered at the site that may have initiated the differential movement of 1;he foundation. These damages do not have a signifcant impact on the structural integrity or req uired design capacity of the wa11s. The ohserved cracking in the concrete slab of the driveway is consistent with conerete shrinkage and/or the effi�ct of therma( expansion and contraction. Concrete slabs on grade shrink after construction inrtially due to thermal volume change as the hydration process(curing)slows. The slab will also c;ontinue to shrink after construction due to drying shrinkage as free water(water not chemically bound during the hydration process) leaves the slab. Both of these shrinkage rnechanisms are inherent in the concrete curing/aging process. In large commercial projects, the use of constri_iction joints and control joints are commonly used to control the random curing/shrinka�;e cracking. The use of construction or control joints in residential construction is not common �md the resulting random cracking in residential slabs on grade is most often covered by interior floor coverings and typically does not present a problem. in general, the darnages observed by SDII are minor in severity and sparsely distributed. The observed conditions are not structurally significant in that they do not compromise the load 3-3