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HomeMy WebLinkAboutSubmission for City CommissionDOUGLAS WOOD & ASSOCIATES, INC. D STRUCTURAL ENGINEERS 299 ALHAMBRA CIRCLE ❑ SUITE 512 CORAL GABLES, FLORIDA 33134 (305) 461-3450 FAX: (305) 461-3650 Report on Present Condition of Structural Systems for Two -Story Residence At 1010 IN.W. 9th Court Miami, Florida January 29, 2004 AFFIRMATIVE ACTION 1 EQUAL OPPORTUNITY EMPLOYER EB 6353 REPORT ON PRESENT CONDITION OF STRUCTURAL SYSTEMS FOR TWO-STORY RESIDENCE AT 1010 N.W. 9TH COURT, MIAMI, FLORIDA INTRODUCTION As requested by the owner, the writer visited the two-story residence at 1010 N.W. 991 Court in Miami and conducted visual observations of the structural systems. The purpose of this investigation was to determine the general condition of the structural systems at this point in time, along with the feasibility of rehabilitating the existing residence. METHODOLOGY AND LIMITATIONS This investigation was conducted by visual observations. Since this is a completed building and since there is restricted space in the crawl space and attic, many of the structural members and/or their connections could not be directly observed, and, in general, we did not destroy existing finishes or other construction to gain visual access to structural members. Also, due to the constraint of time, investigations did not include an exhaustive member by member inspection. Where not directly observed, a sampling of members was observed, or observations were directed at secondary signs of structural distress such as cracks, staining and deflections. Therefore, it must be expected that there are additional deteriorated structural components, which were not directly observed during this investigation. Drawings for the existing construction were not made available to us. Calculations were not performed to verify the adequacy of the original design and construction. It should be noted that the original construction is quite old. The owner reported to the writer that the building was originally constructed in the 1920's. The building codes, practices and materials of the times the residence was constructed were different from those of today. Therefore, it should be remembered that there are many aspects of the existing structural systems, which do not conform to today's standards and codes. This is particularly applicable to the anchorage and lateral bracing of the roof framing and other structural elements. For the purpose of this investigation, and in the absence of a specific observation to the contrary, we assume that all construction was properly designed, permitted, constructed and inspected in accordance with the South Florida Building Code in effect at the time the work was performed. Environmental issues and hazardous materials are not within the scope of this investigation. The owner should consider investigation of these issues prior to any decision to proceed with a proposed project. DESCRIPTION OF SYSTEMS Structural systems include those members and systems of members which are used to support and brace the building against the weights of building materials, superimposed dead loads, live loads and wind loads. For this building, these include foundations, floor framing and sheathing, bearing walls, bearing partitions, stair framing, roof framing and sheathing, concrete beams and columns. They do not include ceiling finishes, doors, windows, non -bearing partition walls, roofing materials, decorative elements, cabinetry, finishes, mechanical equipment, plumbing or electrical systems and driveways. However, where readily apparent while making structural observations, some non-structural items may have been noted and reported herein for the benefit of the owner. f Report on Present Condition of Structural Systems For the Two -Story Residence at 1010 N.W. 9th Court, Miami, Florida January 29, 2004 Page 2 of 5 General: This building is a two-story residence. It appears to be quite old. We estimate that it was probably originally built in the 1920's. It appears that the entire residence is of the original construction, without significant additions or alterations. It appears that there was originally a porch at the south rear area of the residence which was previously removed. Roofs: The lower, flat roof structures are relatively typical of early construction in board sheathing on small wood rafters. The rafters are supported on which are in turn supported on the wood ceiling joists. The ceiling joists are supported by the exterior concrete walls (See Photographs No.'s 2, 5, The upper roof is a sloped roof with wood board sheathing, rafters Photographs No.'s 11, 12, 13, 18, 22 and 26). South Florida with wood wood studs and plates extend into pockets and 8, 9 and 10). and ceiling joists (See Floors: The floor structures primarily consist of finish flooring over wood board sheathing over wood joists. Again, the wood joists bear in pockets on the exterior concrete bearing walls, and concrete beams (See Photograph No. 4). The front entrance porch is a concrete slab -on -ground. Bearing Walls: The exterior bearing walls consist of an unusual construction. They consist of a core of loosely cemented large sized gravel (See Photographs No.'s 17, 19, 30, 31, 32, 33 and 34). There was no fine aggregate or gradation of aggregate in this mix. The result is a honeycombed core of loosely cemented stones. Wood furring strips were embedded directly into the stone/cement mixture on both sides of the wall (See Photograph No. 33). Wood lath was then tacked to the furring strips, and the exterior finished with stucco, and the interior finished with plaster (See Photographs No.'s 1, 17 and 19). The chimney walls are constructed of stucco on 4-inch hollow terracotta tiles. Foundations: The foundations consist of shallow continuous wall footings with cast -in -place concrete stemwalls. NOTED OBSERVATIONS AND EVALUATIONS Roof Structures 1. The main second floor roofing is deteriorated throughout. When viewed from below the roof structure, the roof appears as a sieve, with countless points of light shining through. The roof undoubtedly leaks badly and it appears that it has been in this condition for a long time (See Photographs No.'s 11, 12, 13, 18, 22 and 26). 2. The lower flat roofed areas are equally deteriorated and leaking. The southern lower roof has filled with leaves and dirt to the point where it is supporting significant plant growth. There is a sizable tree growing out of this roof (See Photographs No.'s 2, 5, 8, 9, 10 and 15). The northern roof area also has a small tree growing in it. Report on Present Condition of Structural Systems For the Two -Story Residence at 1010 N.W. 9th Court, Miami, Florida January 29, 2004 Page 3 of 5 3. There are several areas of roof structure which have completely failed due to rot (See Photographs No/'s 5, 18, 22, 26 and 29). 4. The car port roof has been completely removed. it appears that this area was also damaged due to a fire (Photographs No.'s 32, 33 and 34). 5. Almost every structural roof member observed, including the sheathing, rafters, plates, blocking and ceiling joists, has some degree of damage due to rot. Many of these are severely damaged and many (as previously stated) have already failed. 6. Many roof members were also observed to have damage due to insects (See Photographs No.'s 5, 8, 9 and 10). Floor Structures 1. Due to the extreme level of roof leakage throughout the residence over a long period of time, all of the wood floor structures have been damaged by rot. Every member observed has some degree of rot damage. Again, there are a few floor areas which have completely failed (See Photographs No.'s 4, 7 and 16). 2. Many structural floor members were also observed to have damage due to insects. Searing Walls 1. The wood lath and wood furring strips embedded in the exterior stucco and interior plaster are damaged due to rot in most areas. This can be directly observed in several areas where the stucco and plaster have already failed (See Photographs No.'s 1, 17 and 19). It is also evidenced by the widespread areas on the exterior wall which respond with a hollow sound when tapped with a hammer. These hollow sounding areas appear to be delaminating from the concrete stone/cement. 2. The wood furring and blocking embedded in the stucco has deteriorated to failure in a few areas (See Photographs No.'s 17, 20 and 21). 3. The large loose aggregate of the exterior walls is exposed in a few areas. The writer also removed the exterior stucco in two additional places to reveal the stones. In each of these places, the writer could remove some of the loosely cemented large aggregate stones with his fingers (See Photographs No.'s 30 and 31). 4. The stucco veneer over four -inch hollow unreinforced terra Gotta tile at the chimney provides insufficient wind pressure and impact resistance (See Photograph No 27). 5. The stucco -finished, wood -framed walls of the porch (north rear) are severely deteriorated due to rot (See Photographs No.'s 24 and 25). There is a vine growing right through the wall (See Photographs No.'s 23 and 24). 6. It appears that there was another porch at the south rear corner which has already been removed (See Photographs No.'s 28 and 29). 7 The wood studs of the interior bearing partitions (north and south walls of the living room) also exhibit deterioration due to rot. r Report on Present Condition of Structural Systems For the Two -Story Residence at 1010 N.W. 9th Court, Miami, Florida January 29, 2004 Page 4 of 5 8. The roots of the large tree growing on the southern roof have grown right through the concrete wall (See Photograph No. 33). 9. There is cracking and spalling of the concrete beams and columns in the cqr port (See Photographs No.'s 34 and 35). 10. There is spalling concrete at the rear crawl space access opening (See Photographs No. 24). Miscellaneous 1. All of the exterior doors and windows are broken and/or deteriorated. 2. All interior plaster, doors, millwork, finish flooring and cabinetry is damaged due to rot and smoke (See Photographs No.'s 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 and 16). 3. There are no remotely functional mechanical, electrical or plumbing systems. 4. It has been reported to the writer that the existing floor elevation is +7.07 NGVD. It has also been reported that the designated FEMA flood level for this site is +9.00 NGVD. RECOMMENDATIONS For the following reasons it is not possible to successfully rehabilitate this residence: 1. The pervasive deterioration of the wood members requires the complete removal of all roof structures, all floor structures, all wood -framed bearing partitions, and the entire rear porch. 2. The deterioration of all existing finishes, doors, windows, millwork and finish flooring require their complete removal. 3. The deterioration of the embedded wood furring and wood lath in the exterior bearing walls has already proved to be problematic, and this condition will worsen. 4. The loosely cemented gravel exterior bearing walls have inadequate capacity to resist in - plane wind shear forces, lateral wind forces, wind uplift forces and impact forces. 5. The fragile four -inch hollow terracotta tile walls of the chimney are likewise inadequate. 6. The already friable condition of the loosely cemented gravel renders the exterior walls inadequate to receive anchorages for exterior windows and doors. 7. Application of the requirements of the paragraph 3401.8.3.5 of the Florida Building Code, 2001 (commonly referred to as the 50% Rule) would require that all systems, including structural systems, be brought into compliance with current Building Code requirements. This will be impossible to achieve with the present exterior walls. Report on Present Condition of Structural Systems For the Two -Story Residence at 1010 N.W. 9th Court, Miami, Florida January 29, 2004 Page 5 of 5 8. Strict application of the 50% Rule would also require that the first floor be raised approximately two feet to meet current FEMA flood requirements. Again, this would be impossible without complete reconstruction of this residence. 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