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HomeMy WebLinkAbout12022004 BSC Agenda Item 5I I Draft amendment of the Standard Codes Schedule regarding foundations With revisions through 11-29-04 Standard Codes Schedule Adoption. Subject to the amendments and deletions indicated beneath each code, each of the following codes, including all of its published appendices and attachments, is adopted, ordained and made a part of the Code of Ordinances of the City and of each chapter where it is referenced, except as otherwise expressly provided. Procedure for amendments, etc. The procedure for adopting new codes, updated codes, local amendments and provisions for administration and enforcement of these codes is as follows: (1)proposal by the building official or other appropriate City official, (2)referral to the Building&Standards Commission, (3)consideration by the City Council, after giving required meeting notices, and(4)adoption and publication, as required by Article II of the City Charter. International Building Code, 2000 Ed., International Code Council, Inc.. * * * professional enginecr("RPE"), and the work shall bc: . . . : - . .•• - . : _ • 'U. • • , . . • fiuthei- 3. All foundations for new buildings (or additions to existing buildings)with more than one story, or with a gross floor area of 485 square feet or more, must meet the criteria in this section, as applicable. In this section: "A2LA Lab"means a laboratory accredited by the American Association for Laboratory Accreditation on the basis of ISO/IEC 17025:1999 ("general requirements for the competence of testing and calibration laboratories"). "RLPE"means a licensed or registered professional engineer of the State of Texas who is: (1) listed with the State Board of Professional Engineers in either the Page 1 civil or structural branch of engineering (but, from and after May 1, 2006, listing in the structural branch is required); (2) employed by a registered engineering firm of the State of Texas; and (3) covered by professional errors and omissions insurance that: (i) has limits of at least$250,000 per claim (and at least $500,000 per year, aggregate) and(ii) has effective dates—including any retroactive coverage date—that include the entire period when the person provides services or takes actions regulated by this section. "RLGE"means a person who is: (1) either: (a) a registered professional geoscientist of the State of Texas, or(b) a licensed or registered professional engineer who is listed with the State Board of Professional Engineers in a relevant branch of engineering (civil, structural or geological) and employed by a registered engineering firm of the State of Texas; and (2) covered by professional errors and omissions insurance that: (i) has limits of at least$250,000 per claim (and at least $500,000 per year, aggregate) and (ii)has effective dates—including any retroactive coverage date that include the entire period when the person provides services or takes actions regulated by this section. a. Engineering. Foundations must be constructed in accordance with complete plans and specifications prepared, signed and sealed(with a manually-impressed seal and manual signature) by a RLPE. The plans and specifications must be prepared specifically for the site of the work, and they must meet criteria as to scope, content and form specified by the building official. If there are existing trees (either to remain or to be removed)that could affect a foundation, the RLPE must certify that the trees have been taken into account in the preparation of the plans and specifications. b. Geotechnical Report. The plans and specifications for each foundation must be based on a written geotechnical report prepared, signed and sealed by a RLGE. The report must cover all testing and site evaluation, and all must meet all Page 2 applicable criteria in "Recommended Practice for Geotechnical Explorations and Reports"published by the Structural Committee of the Foundation Performance Association, Houston, Texas (Document#FPA-SC-04-0, Rev#0, 11 April 2001, issued for website publishing), a copy of which is on file in the City Secretary's office. Partial exception: If the basic type of foundation is "structural slab with void space and deep foundations"or"structural floor with crawl space and deep foundations,"as described below, the testing, evaluation and report may be limited to a determination of the appropriate depth for the deep foundations, but they must meet the other applicable criteria. The minimum depth of borings is 20 feet in all cases. All tests and other laboratory work must be performed by an A2LA Lab. c. Foundation Performance Standard. For each foundation, the RLPE must certify that the plans and specifications were prepared to achieve a soil-caused foundation movement potential of one inch or less, and that the RLPE used the estimated depth of the active zone and at least two of the following methods to prepare the plans and specifications: (1) Potential vertical rise(PVR) determined in accordance with Test Method Tex-124-E, Rev. January 1, 1978/December 1982, Texas State Department of Highways and Public Transportation, Materials and Test Division, "Method for Determining the Potential Vertical Rise, PVR"(a copy of which is on file in the office of the City Secretary). For this purpose, the "dry"moisture condition(from which little shrinkage is experienced, but where volumetric swell potential is greatest) shall be used for each sample and test. (2) Swell tests performed in accordance with ASTM D4546-03, "Standard Test Methods for One-Dimensional Swell or Settlement Potential of Cohesive Soils"as last revised prior to June 1, 2004. (3) Suction and hydrometer swell tests performed in accordance with ASTM D5298-03 "Standard Test Method for Measurement of Soil Potential (Suction)Using Filter Paper"and ASTM D6836-02 "Standard Test Methods for Determination of the Soil Water Characteristic Curve for Desorption Using a Hanging Column, Pressure Extractor, Chilled Mirror Page 3 f Hygrometer, and/or Centrifuge,"as such methods were last revised prior to June 1, 2004. (Partial exception: If the basic type of foundation is "structural slab with void space and deep foundations" or"structural floor with crawl space and deep foundations,"as described below,neither a PVR determination nor a swell, suction or hydrometer test is required.) d. Foundations, Basic Types. Each foundation must be of an approved basic type. Approved basic types are listed below. In this list, types of foundations are defined and described in "Foundation Design Options For Residential and Other Low-Rise Buildings on Expansive Soils"published by the Structural Committee of the Foundation Performance Association, Houston, Texas (Document#FPA- SC-01-0, Rev#0, 30 Jun 04,marked"For Website Publishing"), a copy of which is on file in the City Secretary's office ("FDO"). (1) Structural slab with void space and deep foundations. (2) Structural floor with crawl space and deep foundations. (3) Stiffened structural slab with deep foundations. (4) Stiffened non-structural slab with deep foundations. (5) Grade-supported stiffened structural slab. (6) Grade-supported stiffened non-structural slab. (7) Grade-supported non-stiffened slab of uniform thickness (approved for one-story buildings--or additions to buildings--containing only garage or storage space,not habitable space). (8) Mixed-depth system for all new building construction. (9) Mixed-depth system for building additions with deep foundations. (10) Another type approved by special exception issued by the BSC. See (h), below. e. Foundations, Deep Support Components. Deep support components must be of an approved type. Approved types are listed below. In this list, types of deep support components are defined and described in FDO. (1) Drilled and underreamed concrete piers. (2) Drilled straight-shaft concrete piers. (3) Auger-cast concrete piles. Page 4 1 (4) Another type approved by special exception issued by the BSC. See(h), below. f. Foundations, reinforcement. Reinforcement for each foundation must be of an approved type. Approved types are listed below. In this list, types of reinforcement are defined and described in FDO. (1) Deformed bar reinforcing. (2) Welded wire fabric reinforcing(approved for one-story buildings--or additions to buildings--containing only garage or storage space, not habitable space). (3) Another type approved by special exception issued by the BSC. See(h), below. g. Foundations, Observation & Certification. Each foundation must be professionally observed and must be certified by an RLPE, as more fully described below: (1) Observations must: (i) be performed either by the certifying RLPE or by one or more persons under that RLPE's direct supervision and control whose professional qualifications are approved by the RLPE (any such person may be an RLGE, with respect to geophysical matters), (ii) include actual measurement of piers, fill, compaction, reinforcement, forms, materials, dimensions, structural elements, stressing, tendons,tensions, attachments, etc. before the work is covered or concrete is placed, (iii) be performed continuously during placement of concrete and any stressing or tensioning operations, and (iv) be documented in a form and manner approved by the building official (which may include photographs). (2) Certifications must: (i) refer to and be based upon the professional observations required by this section, Page 5 (ii) state that the work complies with the plans and specifications last approved by the building official (with any field changes that are ordered by the RLPE and reported to the building official and that comply with applicable regulations), (iii) state that the work complies with sound engineering practices, (iv) comply with criteria as to form and content as may be specified by the building official, (v) be signed and sealed by the certifying RLPE, and (vi) be filed with the building official. (3) Certifications may: (i) rely in part upon an attached certification by a RLGE, as to geophysical matters, and (ii) rely in part upon an attached certification by an A2LA Lab, as to materials testing. Before framing or other work commences atop a foundation(and before the foundation is otherwise covered), the permittee must obtain written acknowledgment from the building official that the certification for the foundation was duly filed as required above. Certifications, plans, specifications and related items may be kept on file by the City, for public inspection, for an indefinite period of time. h. Special Exceptions. The BSC may issue a special exception from any requirement in subsection"a"through "g,"above, but only upon a showing that: (1) the requirement will not affect life safety or the performance of a structure (for its estimated useful life); or (2) an alternate requirement to be imposed by the special exception will provide equal or better protection for life safety and long-term structural performance. In connection with any such special exception, the BSC may require that the applicant provide supporting engineering data and opinion, and the BSC may impose conditions to carry out the purpose and intent of applicable regulations. Page 6 • 1 4. All concrete piers, footings and foundations must be cured for at least 72 hours before any significant load is placed on them. 5. All walls and ceilings within a R-1, R-2, R-3 and R-4 type occupancy shall be sheathed with Type X gypsum board at least 5/8-inch (15.9 mm) thick. Exception: Where this code(IBC)requires otherwise for moisture protection. 6. Delete: Appendices A (Employee Qualifications), B (Board of Appeals)and D (Fire Districts). * * * Page 7 OPTIONAL ORDINANCE LANGUAGE FOR ACCESSORY STRUCTURES Note: Normally,these actions must be processed through the variance procedures. However,communities may wish to include provisions in their floodplain management ordinances for permitting the construction of accessory structures. Approval from the FEMA Region VI office is required prior to adoption. DEFINITION OF ACCESSORY STRUCTURE to be included in the DEFINITION section Structures which are on the same parcel of property as the principle structure and the use of which is incidental to the use of the principle structure (such as garages and storage sheds). STANDARDS FOR ACCESSORY STRUCTURES to be included in the appropriate regulatory section of the floodplain management ordinance The construction of such structure must satisfy the following standards in unnumbered and numbered A Zones: 1. Structure is low valued and represents a minimal investment 2. Structure shall small in size,not exceed 600 square feet in size. 3. Structure shall be unfinished on the interior. 4. Structure can be used only for parking and limited storage. 5. Structure shall not be used for human habitation(including work, sleeping, living, cooking, or restroom areas). 6. Service facilities such as electrical and heating equipment must be elevated to or above the BFE or floodproofed. 7. Structure is constructed and placed on building site so as to offer the minimum resistance to the flow of floodwaters. 8. Structure is designed to have low flood damage potential i.e. constructed with flood resistance materials. 9. Structure is firmly anchored to prevent flotation, collapse, and lateral movement. 10. Floodway requirements must be met in the construction of the structure. 11. Openings to relieve hydrostatic pressure during a flood shall be provided below the BFE No accessory structures are allowed in V Zones except for"disposable" sheds. If constructed, fill cannot be used for structural support and the areas below the BFE must remain free of obstruction or be constructed with non-supporting breakaway walls, open latticework, or insect screening. All accessory structures are to be located so as not to cause damage to adjacent and nearby structures.