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Safety and Buildings Division Structural Requirements (Commercial Buildings) Code Council Meeting Summaries Meeting summaries are tentative until reviewed at a subsequent meeting.
Friday, October 30,
2009, 9 a.m. - noon, Room 3B, Thompson Commerce Center,
201 West Washington Avenue, Madison, Wisconsin Gusests: Joel Anderson, KJWW Engineering Consultants; Wayne Vandenbergh, KJWW Engineering Consultants Bob Schumacher opened the meeting with a welcome and a review
of the agenda. The council accepted the draft progress report
for the preceding council meeting on September 16, 2009, after agreeing
to delete the paragraph addressing steel decks on page 4. A motion was made by Mike West, seconded by John Rave, and
passed unanimously, to modify chapter 18 of the 2009 edition of the IBC
as agreed, for both ground-improvement systems and for allowable loads
on driven piles.
Chapter 19 – Concrete
The council did not recommend any modifications for the 2009 changes to IBC chapter 19. In reviewing the Wisconsin modifications in Comm 62 for
chapter 19 of the 2006 IBC, Sam Rockweiler noted several of the
modifications may be replaced with a general rule in chapter Comm 61
that would globally delete all mandates to get an approval from a local
building or fire code official. Similar global deletions in
Comm 61 could likewise allow deleting numerous other individual
modifications relating to submittal of construction documents, special
inspections, construction in flood hazard areas, detached one- or
two-family dwellings, and local permits or certificates of occupancy.
Chapter 21 – Masonry
The council did not recommend any modifications for the 2009 changes to IBC chapter 21. In reviewing the Wisconsin modifications in Comm 62 for chapter 21 of the 2006 IBC, there was agreement to delete section Comm 62.2109(1) because the lintel design requirements there are included in section 2109.3.4.7 of the 2009 IBC. For openings in exterior masonry walls, Larry indicated staff would review the requirements in ACI standard 530 and TMS standards 402 and 602, which are incorporated into the 2009 IBC, to determine whether the corresponding requirements in Comm 62.2109(2) should be deleted or revised. The requirements in Comm 62.2109(3) for expansion and jointing in exterior masonry walls will be retained because they are not included in the 2009 IBC or its incorporated standards.
Next Steps
Wednesday, September 16, 2009, 9 a.m. to 3 p.m. Conference Room 3B, Thompson Commerce Center, 201 West Washington Ave., Madison, WI.
Attendance
Bob Schumacher opened the meeting with a review of the agenda, and the Council accepted the draft progress report for the preceding, August 5, 2009, Council meeting, after agreeing to change “high-end welding or bolting” to “welding or bolting in complex structures” in the paragraph for truss inspections on page 2. Review of draft 2009 changes to International Building Code® chapters 18, 20, 22, 24 and 25
Chapter 18 – Soils and Foundations
Mike Oliva asked whether the design is based on allowable or factored loads. Mike West noted that although foundation design for bridges can be based on factored loads, foundations for buildings continue to be based only on allowable stress design. Mike West suggested clarifying that the maximum allowable load or bearing stress may not exceed one-third of the calculated ultimate bearing capacity. John Rave asked how that factor of safety compares to foundation designs which do not include ground improvement, and Al explained a factor of 3 is typical, but can be reduced to 2.5 for piles if dynamic testing is included. Mike Oliva asked where the maximum differential settlement of ¾ inches, and the maximum total settlement of 1 inch, are derived from. John noted they are widely used industry standards, – Al explained some structures can tolerate more, but some specialized structures may need less. Al explained the draft requirements are intended for native soils rather than fill, and they fit with other requirements for shallow foundations, since the purpose of ground improvement systems is to avoid needing deep foundations. Al agreed to develop a list of methods that the requirements can be used for, and to redraft the requirements to reflect the discussion. In reviewing the setback requirements in IBC section 1803.5.10, Sam Rockweiler noted that the reference to “building official” there, and likewise throughout the IBC, may be modified through a general rule near the beginning of chapter Comm 61, rather than individually deleted from each reference in the IBC, which the current version of Comm 60 to 66 does. The main purpose of this deletion or modification is to avoid imposing unfunded mandates on local officials. Mike West recommended retaining the corresponding references for being able to obtain specific approvals from the Department or local officials, for unusual circumstances. In reviewing the requirements in IBC section 1803.6 for reporting geotechnical investigations prior to permit issuance, Al recommended deleting the requirement to include driving criteria for deep foundations, as referenced in IBC 1803.5.5. Al explained the driving criteria is typically not developed until the construction stage, and should instead be required then, such as in conjunction with the requirements for driving criteria in IBC section 1810.3.3.1.1. Mike West agreed. John indicated that currently geotechnical reports typically are not submitted, and are instead referenced in the submittal. John recommended modifying IBC 1803.6 to only have the geotechnical reports submitted where required by the building official. Larry Swaziek indicated the reference to obtaining a local permit would likewise be deleted, to avoid imposing an unfunded mandate on local officials. The Council agreed to delete the driving criteria from IBC section 1803.5.5; and to modify IBC 1803.6 to not refer to permit issuance and to only have the geotechnical reports submitted where required by the building official. In reference to the requirements for flood hazard areas, Sam explained that as with the references to “building official,” a general modification may be added near the beginning of chapter Comm 61 to show that construction typically is not allowed in flood areas, rather than individually deleting each reference as in the current version of chapters Comm 60 to 66. In reviewing the requirements in IBC section 1805.4 for a gravel or crushed-stone base course for basement floors, Al noted concern for migration of silt and fine sand into the base course, and recommended requiring a geotextile fabric below the base course. In reviewing the requirements in IBC section 1806.2 for presumptive load-bearing values, Larry noted the Department may continue to apply the Wisconsin modification in section Comm 62.1805 (2) that allows use of design criteria for post foundations in ANSI/ASAE EP 486.1 in lieu of the design criteria in IBC section 1807.3.2. In reviewing the requirements in IBC Table 1806.2 for presumptive load-bearing values, Al noted the values are accurate for moist soils but not for saturated soils, because buoyant soils provide only about half as much structural resistance. Al recommended adding a footnote that would reduce the values by half for saturated soils – which would be consistent with footnote a for Table 1610.1. That footnote currently recognizes how lateral loads on a foundation wall or retaining wall that are caused by saturated soils differ from the loads caused by unsaturated soils. Al noted that the requirements for allowable bearing capacity and settlement in IBC section 1808.2 are more generalized than the specific criteria in his draft requirements for ground improvement. In reviewing the requirements in IBC section 1809.5 for frost-protected shallow foundations, Larry noted there may be interest in posting a notice that the design is based on heating occurring during frost conditions. Al emphasized a need to retain the requirements in Comm 62.1808 (1) and (2) for neutral plane and downdrag. Mike West noted the requirements in IBC section 1810.3.1.5 provide little guidance for helical piles. There was agreement that the references in Comm 62.1808 (3) (f) to “occupiable” and “nonoccupiable” structures should be changed to structures in “occupancy categories II to IV,” and “occupancy category I,” respectively. Al noted the alternate criteria for pile capacity in Comm 62.1808 (4) can be deleted because they are now included under the Davisson Offset Limit referenced in IBC section 1810.3.3.1.3. However, an informational note could be provided for this section to identify any other load-test evaluation methods that are currently acceptable to the Department. Al recommended deleting the exception under IBC section 1810.3.3.1.5. The exception allows reducing the factor of safety for uplift due to wind or seismic loading if the capacity is determined by analysis and load tests. Al explained the reduction is unwarranted because of the uncertainty in the calculations and because there is no redundancy during uplift – as there is during compression, from having both side and toe bearing then.
Chapter 20 – Aluminum
Chapter 22 – Steel
In reference to the requirements in IBC section 2209.2 for steel decks, Mike West noted the table in the referenced standards includes values that have not been independently verified. In reviewing the steel truss requirements in IBC section 2210.3.4, Mike West noted the new requirement to have a registered professional design both temporary and permanent bracing for spans of 60 feet or greater matches the same new requirement for wood trusses. As with wood trusses, this 2009 IBC change newly applies the registered-designer requirement to temporary bracing during construction – instead of continuing to have the construction contractor responsible for it then. As with the requirement for wood trusses, the Department may delete this requirement. In reference to the requirements in IBC section 2210.7 for steel framing for detached one- and two-family dwellings, Sam explained that as with the references to “building official,” a general modification may be added near the beginning of chapter Comm 61, in conjunction with the current Note 3 under Comm 62.0100, to further clarify that detached one- and two-family dwellings are addressed by chapters Comm 20 to 25 rather than Comm 60 to 66.
Chapter 24 – Glass and Glazing
Chapter 25 – Gypsum Board and Plaster
Welding
Next Meeting The next meeting was set for October 30, 2009, at the same location and time, with a focus on reviewing chapters 19 and 21 in the 2009 IBC. Wednesday, August 5, 2009, 9 a.m. to 3 p.m. Conference Room 3B, Thompson Commerce Center, 201 West Washington Ave., Madison, WI.
ATTENDANCE
Department of Safety and Professional Services STAFF: Steve Dobratz, Sam Rockweiler and Larry Swaziek Larry Swaziek opened the meeting with a welcome, a round of introductions, a review of the agenda, and an overview of the electronic version of chapters 16 to 25 in the draft 2009 International Building Code® that he made available to the Council prior to the meeting. The draft included arrows showing where text has been deleted, and sidebars showing the IBC sections that have been revised – except in chapter 18, where the entire chapter has been revised and reorganized. The Council subsequently elected Bob Schumacher and Mike West as chair and vice chair, respectively. Review of the draft 2009 changes to IBC chapters 16 to 25
Chapter 23
In reviewing the truss requirements in IBC section 2303.4, Mike West questioned whether the new requirement in 2303.4.1.3 to have a registered professional design both temporary and permanent bracing for truss spans of 60 or greater should also apply to shorter spans. Steve Cramer noted substantially more guidance is available for spans under 60 feet, but Mike indicated the guidance is typically too general. Mike emphasized that the 2009 change newly applies the registered-designer requirement to temporary bracing during construction – instead of continuing to have the construction contractor responsible for it then – which is very unusual in the IBC and elsewhere in the industry. John Rave recommended that truss bracing be designed by the truss manufacturer, and asked why the Wisconsin Commercial Building Code currently excludes the 2006 IBC requirements for truss design drawings. Larry responded that the design drawings and other construction documents are addressed instead in chapter Comm 61 of the Wisconsin Code. Larry added that each of the current Wisconsin modifications of the IBC which are retained will be reviewed and updated where needed to be consistent with any 2009 IBC section numbering that differs from the numbering in the 2006 IBC. In reviewing the truss inspections in IBC sections 2303.4.6 and 2303.4.7, Larry noted that the Wisconsin Code typically defers to the designer for deciding whether to require third-party inspections, and Mike West explained that such inspections tend to occur in applications such as high-end welding or bolting. Larry summarized that the Department would likely (1) delete IBC section 2303.4.1.1; (2) review and possibly delete section 2303.4.1.3; (3) delete sections 2303.4.1.4.1, 2303.4.2, and 2303.4.3; (4) delete the last sentence of section 2303.4.6; and (5) delete section 2303.4.7. In reviewing the design requirements for lateral-force-resisting systems in IBC section 2305, and the criteria for allowable stress design in IBC section 2306, it was noted that the 2009 changes primarily consist of replacing general requirements with references to consensus standards, particularly for wind and seismic loads. The load and resistance factor design criteria in section 2307 are likewise changed to reference the American Forest and Paper Association design standard for wind and seismic loads. Staff noted the published 2009 IBC newly italicizes defined terms in the code text whenever they have the meaning that is specified in IBC chapter 2 – such as in section 2308.3.3, where “stories in height” is changed to “stories above grade plane.”
Chapter 16
Staff noted the 2009 IBC moves the requirements for posting large live loads from chapter 16 to section 106in chapter 1 – however, all of chapter 1 in the 2006 IBC is currently deleted by section Comm 62.0100 of the Wisconsin Code. The Council agreed that the current modification in section Comm 62.1603 (5) to post design live loads which exceed 100 pounds per square foot is still needed, and could be renumbered to be near other signage requirements, or to be in addition to the special detailed requirements based on use and occupancy in IBC chapter 4. The Council also agreed the threshold for posting should remain at 100 psf. Staff noted the Department will likely continue to delete the criteria for flood loads in IBC sections 1605.2.2, 1605.3.1.2, and 1612, since construction in flood areas is not allowed in Wisconsin. In reviewing the uniform live loads for townhouses in Comm Table 1607.1, Mike West questioned whether the 5 psf load for uninhabitable attics without storage should be either deleted or also applied elsewhere. Larry and Bob Schumacher noted attics in 1- and 2-family dwellings historically have been used for some storage, and Larry indicated the 5 psf load would likely not be deleted. Mike recommending (1) applying the 5 psf load to uninhabitable attics without storage in all residential occupancies; (2) similarly applying the Table’s 20 psf load for uninhabitable attics with storage, in townhouses, to all residential occupancies; and (3) similarly applying the Table’s 40 psf load for all other areas in townhouses, except balconies, to habitable attics in all residential occupancies. These changes could be added after line 4 or 27 or 40 in Table 1607.1 of the 2009 IBC. Staff noted that uniform live loads for exterior balconies and decks have been changed in line 5 of Table 1607.1 in the 2009 IBC to be the same as the occupancy served, rather than 100 psf – so the exception in Comm Table 1607.1 which has resulted in a load of 100 psf for balconies will likely be deleted. In discussing the requirements in section Comm 62.1608 (2) for drifted or sliding snow on roofs that are horizontally within 15 feet of taller roofs, there was agreement that a long-enough roof can cause similar drifted-snow loads on a roof which is horizontally within 15 feet but at the same elevation. Larry noted the Department will likely continue to apply the current requirements rather than expand them to also address long roofs at the same elevation. In reviewing the new text in IBC section 1610.1 for the pressure on foundation walls from undrained backfill, Al Wagner noted that the superfluous reference to the “weight of the” pressure should be deleted. In discussing the design rain loads in IBC section 1611.1, Larry agreed to review whether the Department’s plumbing code requirements include prescribed rain loads that could be used in lieu of newly basing the rain load on the 100-year hourly rainfall rates in IBC Figure 1611.1. In discussing the site classes for earthquake loads in IBC section 1613.5.2, the Council noted several projects where substantial cost savings have resulted from extending the subsurface support to underlying soil strata that have better seismic resistivity. It was noted that all of the requirements in IBC section 1614 for structural integrity are new, especially for structural steel.
Chapter 17
Chapter 18
Next Meeting The next meeting was tentatively set for September 2, 2009, at the same location and time, with an initial focus on completing review of chapter 18 in the 2009 IBC. [The meeting date was subsequently changed to September 16.] , 9 to 2 p.m., room 3B; Thompson Commerce Center, 201 West Washington Avenue, Madison, Wisconsin Council Member Attendance: Greg Bares - Present; Steven Cramer - Excused; David Hyser - E; Michael Oliva - P; John Rave - P; Robert Schumacher (Chairperson) - P; Alan Wagner - P; Michael West - P. Department of Safety and Professional Services Staff: Steve Dobratz, Sam Rockweiler; Larry Swaziek. Robert Schumacher opened the meeting, and the Council accepted the draft meeting summary from the preceding, March 11 meeting. Review of draft code changes Sam Rockweiler led discussion of the draft rule changes that were emailed to the committee on October 14, which were developed from discussions at the preceding five meetings. The council agreed that in adopting the 2006 edition of the International Building Code, current section Comm 62.1615, as revised in the draft rules, is no longer needed for deleting a 15 percent g seismic contour in southeastern Wisconsin, because the 2006 IBC moves this seismic contour to below the southern border of Wisconsin. Larry agreed to verify whether the seismic parameters on the corresponding U.S. Geological Service Web site have been updated to be consistent with the 2006 IBC. Larry reported that the department’s Commercial Building Code Council and the Multifamily Dwelling Code Council have both noted concerns with continuing to apply seismic design criteria in Wisconsin. Larry explained that the department does not expect to discontinue the application, but is looking for ways to ease compliance with the criteria. Larry noted the draft rules do not yet reflect a complete identification of the 2005 changes to Comm 62 that can be repealed because they are addressed in the 2006 IBC. Sam noted that the draft rules likewise do not yet reflect review of any new references in the 2006 IBC to detached one- or two-family dwellings, flood loads, or required approvals from local jurisdictions. The council agreed that proposed Comm 62.1808(2) in the draft rules is no longer needed for deleting a maximum settlement of piles, because the final version of the 2006 IBC no longer includes this maximum. 2006 changes to IBC chapters 16 to 25 Larry explained that the 2006 changes to IBC chapters 16 to 25, which were displayed in the reference materials he transmitted to the council on October 11, consisted of (1) code change proposals that the International Code Council had presented at a public hearing in Cincinnati, and (2) subsequent code changes that the ICC voted on in Detroit at the end of September. Larry noted that of the 226 structural-related code change proposals which were presented to the ICC, 24 were eventually withdrawn, 50 were disapproved, 72 were approved as submitted, 70 were approved after being modified by an ICC review committee, and 10 were approved in Detroit after being modified to reflect the hearing results. Larry led discussion of the 2006 changes, beginning with the list of highlights that was included in the October 11 transmittal. In discussing the highlights, the council noted that (1) the changes for wind loads in IBC section 1609 reflect updating to achieve consistency with updated criteria in the referenced ASCE 7 design standard from the American Society of Civil Engineers; (2) the changes for foundation walls in IBC Table 1805.5(2) are helpful in providing more detail, and designers can continue to engineer the design of the walls rather than use the Table; (3) the extensive changes in IBC chapters 19 and 21 reflect updating to achieve consistency with updated criteria in standards 318 and 530 from the American Concrete Institute; (4) the changes in IBC 2304.8, 2306.1, and 2306.1.4 incorporate detailed design criteria for tongue-and-groove lumber decking that are needed because they are no longer promulgated as a separate standard; and (5) the changes in IBC 2203 and 2205.1 adopt an updated structural steel specification from the American Institute of Steel Construction - that advances a trend toward more reliance on the load and resistance factor design method rather than on the allowable strength design method, which may be a significant change for some designers. In discussing the remaining 2006 changes, the council noted that (1) in IBC Table 1604.5, the assignment of an importance factor for assembly occupancies is changed from being based on the number of people who congregate in an area of a structure, to the number in the primary occupancy for the entire structure; (2) numerous IBC sections were simplified and condensed, under code-change proposal S39-04/05, in conjunction with no longer having these sections reprint many of the requirements in the ASCE 7 design standard; (3) the changes for truss-design drawings in IBC 2303.4.2, 2303.4.4 and 2303.4.5 should be helpful, and the requirements for the drawings should be retained - rather than deleted, as they currently are in Comm 62 - but the changes still do not adequately address the permanent-bracing details that are needed from truss designers. Mike West agreed to submit draft text addressing the bracing details. The council concluded its discussion by agreeing to accept all of the 2006 changes to IBC chapters 16 to 25. Scheduling of further meetings was postponed until after public hearings are held for proposed changes to Comm 61 to 65. Friday, March 11, 2005, 9:30 a.m. to 2 p.m., Room 3B, Thompson Commerce Center, 201 West Washington Avenue, Madison, Wisconsin Council Member Attendance: Greg Bares – Present; Steven Cramer – Excused; David Hyser - P; Michael Oliva – P; John Rave – P; Robert Schumacher (Chairperson) – P; Alan Wagner - P; Michael West – P Commerce Staff: Sam Rockweiler, Larry Swaziek Larry Swaziek opened the meeting with a review of the agenda, and the Council accepted the draft meeting summary from the preceding, February 11th meeting.
Updates on unresolved
topics
from the February 11 meeting
Sam Rockweiler noted that the rationale for a recent requirement to separate secondary roof-drain systems from primary roof-drain systems was sent to the Council members on March 8. There was agreement that the rationale adequately explained the need for the separation; and agreement that the January 1, 2005, changes to Comm 62.1507 are offsetting the difficulty of separating the two roof-drain systems, by allowing roof slopes of less than two percent.
2003 and 2004 IBC
chapter 17
changes
A motion was made by Bob Schumacher, seconded by Mike Oliva, and passed unanimously, to continue deleting the requirements for special inspections, testing, and structural observations, in IBC 1707 to 1709, for seismic resistance. Based on discussion at the preceding meeting, and on agreement that the included criteria would be helpful rather than burdensome, a motion was made by John Rave, seconded by Bob Schumacher, and passed unanimously, to no longer delete the criteria for design strength of materials, alternative test procedures, safe-load testing, in-situ tests, and preconstruction load tests, in IBC 1710 to 1714, and to accept the 2003 and 2004 IBC changes to these sections. A motion was made by Bob Schumacher, seconded by Mike Oliva, and passed unanimously, to continue deleting the requirements for quality assurance for seismic resistance and wind resistance, in IBC 1705 and 1706. In discussing the special inspections that are addressed in IBC 1704, Mike West commented that they are intended to all be conducted by an independent, third party. John Rave noted that requiring these inspections in Wisconsin would create a new industry. Alan Wagner noted he was opposed to the preceding deletion of the inspection requirements in 1704.7 for fill placement, because of too many problems he has observed that resulted from inadequate oversight; and he said that the inspections referenced in 1704.9 should be required for all pier foundations rather than only for those in Seismic Design Categories C to F. Mike West agreed that inspections for fill are important and significant, and he requires them. However, Mike questioned whether they relate to life-safety, and Alan indicated they likely only would be in extreme circumstances. Alan added that the inadequate oversight is an occasional problem rather than a widespread problem, and the Council should consider what can be done to reduce the problem. Mike commented that other parts of 1704 also address inspections which are generally good to do, but similarly not related to life-safety - and if the Council recommends no longer deleting the inspections in 1704.7.2 and 1704.9, then it would have to also recommend no longer deleting the inspections in the other parts of 1704. Mike added that the requirements for concrete in ACI 318 include criteria for testing concrete, but do not specify who must do the testing. John Rave suggested that the oversight which Alan recommended be added to the requirements for soils and foundations in IBC Chapter 18, without specifying that the oversight must be by an independent, third party. Mike noted that the building owner and designer typically can adequately address testing in their contracts. For comparison, John commented that welds in structural steel can visually appear adequate, which is generally the extent of their inspection, but they can then be inadequate for life-safety. Mike Oliva asked whether adequacy of fill is addressed elsewhere in the IBC, and Alan explained that 1803.4 has requirements for footings which bear on compacted fill. Mike West noted that building inspectors can require evidence of compliance with 1803.4. There was discussion that the amount of associated testing is project-dependent, and Dave Hyser commented that the amount needed is determined by professional judgement, but is generally not a life-safety issue. Alan commented that driven piles have corresponding testing, and consequently have not had the problems he has observed elsewhere. Larry explained that the Insurance Services Organization has determined that Wisconsin ’s requirements for construction oversight by supervising professionals are equivalent to the special inspections required in IBC 1704. A motion was made by Dave Hyser, seconded by John Rave, and passed with a dissenting vote from Alan Wagner, to continue deleting the requirements for special inspections in IBC 1704. A motion was made by John Rave, seconded by Dave Hyser, and passed unanimously, to continue deleting the general criteria, definitions, and approval requirements in IBC 1701 to 1703.
Clarifying seismic
design
requirements
2005 IBC public hearing
in Cincinnati
Structural requirements
for
existing buildings
Next meeting
Friday, March 11, 2005, 9:30 a.m. to 2 p.m., Room 3B, Thompson Commerce Center , 201 West Washington Avenue, Madison, Wisconsin Council member attendance: Greg Bares Present; Steven Cramer Excused; David Hyser P; Michael Oliva P; John Rave P; Robert Schumacher (Chairperson) P; Alan Wagner P; Michael West P
Larry Swaziek opened the meeting with a review of the agenda, and the council accepted the draft progress report from the preceding, February 11th meeting.
Updates
on unresolved topics from the February 11 meeting
Sam Rockweiler noted that the rationale for a recent requirement to separate secondary roof-drain systems from primary roof-drain systems was sent to the Council members on March 8. There was agreement that the rationale adequately explained the need for the separation; and agreement that the January 1, 2005, changes to Comm 62.1507 are offsetting the difficulty of separating the two roof-drain systems, by allowing roof slopes of less than two percent. 2003 and 2004 IBC chapter 17 changes The was agreement to accept the 2003 and 2004 IBC changes to the requirements for joist hangers in Sections 1715.1.4 and 1715.1.2, respectively. A motion was made by Bob Schumacher, seconded by Mike Oliva, and passed unanimously, to continue deleting the requirements for special inspections, testing, and structural observations, in IBC 1707 to 1709, for seismic resistance. Based on discussion at the preceding meeting, and on agreement that the included criteria would be helpful rather than burdensome, a motion was made by John Rave, seconded by Bob Schumacher, and passed unanimously, to no longer delete the criteria for design strength of materials, alternative test procedures, safe-load testing, in-situ tests, and preconstruction load tests, in IBC 1710 to 1714, and to accept the 2003 and 2004 IBC changes to these sections. A motion was made by Bob Schumacher, seconded by Mike Oliva, and passed unanimously, to continue deleting the requirements for quality assurance for seismic resistance and wind resistance, in IBC 1705 and 1706. In discussing the special inspections that are addressed in IBC 1704, Mike West commented that they are intended to all be conducted by an independent, third party. John Rave noted that requiring these inspections in Wisconsin would create a new industry. Alan Wagner noted he was opposed to the preceding deletion of the inspection requirements in 1704.7 for fill placement, because of too many problems he has observed that resulted from inadequate oversight; and he said that the inspections referenced in 1704.9 should be required for all pier foundations rather than only for those in Seismic Design Categories C to F. Mike West agreed that inspections for fill are important and significant, and he requires them. However, Mike questioned whether they relate to life-safety, and Alan indicated they likely only would be in extreme circumstances. Alan added that the inadequate oversight is an occasional problem rather than a widespread problem, and the Council should consider what can be done to reduce the problem. Mike commented that other parts of 1704 also address inspections which are generally good to do, but similarly not related to life-safety – and if the Council recommends no longer deleting the inspections in 1704.7.2 and 1704.9, then it would have to also recommend no longer deleting the inspections in the other parts of 1704. Mike added that the requirements for concrete in ACI 318 include criteria for testing concrete, but do not specify who must do the testing. John Rave suggested that the oversight which Alan recommended be added to the requirements for soils and foundations in IBC Chapter 18, without specifying that the oversight must be by an independent, third party. Mike noted that the building owner and designer typically can adequately address testing in their contracts. For comparison, John commented that welds in structural steel can visually appear adequate, which is generally the extent of their inspection, but they can then be inadequate for life-safety. Mike Oliva asked whether adequacy of fill is addressed elsewhere in the IBC, and Alan explained that 1803.4 has requirements for footings which bear on compacted fill. Mike West noted that building inspectors can require evidence of compliance with 1803.4. There was discussion that the amount of associated testing is project-dependent, and Dave Hyser commented that the amount needed is determined by professional judgement, but is generally not a life-safety issue. Alan commented that driven piles have corresponding testing, and consequently have not had the problems he has observed elsewhere. Larry explained that the Insurance Services Organization has determined that Wisconsin’s requirements for construction oversight by supervising professionals are equivalent to the special inspections required in IBC 1704. A motion was made by Dave Hyser, seconded by John Rave, and passed with a dissenting vote from Alan Wagner, to continue deleting the requirements for special inspections in IBC 1704. A motion was made by John Rave, seconded by Dave Hyser, and passed unanimously, to continue deleting the general criteria, definitions, and approval requirements in IBC 1701 to 1703. Clarifying seismic design requirements Larry distributed maps showing the seismic design categories for IBC Use Groups I, II and III, based on soil types A to C, D, and E, in Wisconsin; and he included the corresponding guidance article the Department has published for designers, which includes reference to the USGS Web site that displays whether an inputted zip-code area is north or south of the 4% g contour line in IBC Figure 1615(2). Larry agreed to post the guidance article on the Department’s Web site, and John reported that ASCE has produced a corresponding compact disc that is helpful.
2005
IBC public hearing in Cincinnati
Structural
requirements for existing buildings
Larry explained that the next meeting is expected to occur in the Fall of 2005, when a complete draft of the 2006 IBC changes becomes available for review. Larry said he would present the Council’s output from the five meetings since November 2004 to the Department’s advisory council’s for commercial buildings and for multifamily dwellings, which are scheduled to jointly meet on April 28 at the Holiday Inn Madison East. Friday, February 11, 2005, 9:30 a.m. - 3 p.m., Conference Room 3B, Thompson Commerce Center, 201 West Washington Avenue, Madison, Wisconsin Council member attendance: Greg Bares Present; Steven Cramer P; David Hyser P; Michael Oliva P; John Rave P; Robert Schumacher (Chairperson) P; Alan Wagner P; Michael West Excused
Commerce staff: Sam Rockweiler,
Larry Swaziek
2003 and 2004 IBC chapter 16
changes
Snow loads: John Rave commented that the county-line based, ground-snow-load zones which are shown in Comm Figure 62.16-1 as simplified alternatives to the isobar-based zones in IBC Figure 1608.2 are not as useful as the zones that result from enlarging the Wisconsin portion of IBC Figure 1608.2 to equal or exceed the size of Comm Figure 62.16-1. A motion was made by John Rave, seconded by Greg Bares, and passed unanimously, to replace the simplified ground-snow-load zones in Comm Figure 62.16-1 with the Wisconsin portion of IBC Figure 1608.2, as enlarged to equal or exceed the size of Figure 62.16-1. Corresponding discussion included agreement that indicating the county names on the enlarged map would be helpful, and included recognition that the Department may choose to retain the simplified zones if enforcement difficulties would result. John indicated that the option in Comm 62.1608 (2) to use a snow exposure factor of 1.0 for any flat roof is an oversimplification and should be repealed. A motion was made by John Rave, seconded by Greg Bares, and passed unanimously, to repeal Comm 62.1608 (2). Larry Swaziek distributed and discussed sample calculations, and corresponding excerpted text, for illustrating the unbalanced roof snow loads that are predicted by the 1998, 2002, and 2005 editions of ASCE standard 7, as compared to the loads predicted by the alternative, Canadian-based equation which was incorporated into Comm 62.1608 (3) on January 1, 2005. A motion was made by John Rave, seconded by Greg Bares, and passed unanimously, to retain the alternative equation in Comm 62.1608 (3) for unbalanced roof snow loads. The discussion included agreement that Comm 62.1608 (3) adequately addresses roofs with slopes of 15 degrees or less. Wind loads: There was agreement that the alternative, simplified wind loads in Comm 62.1609 (1) for building components and cladding are no longer needed, but the substituted text in Comm 62.1609 (2) for wind loads on low-rise buildings is still appropriate. A motion was made by John Rave, seconded by Dave Hyser, and passed unanimously, to repeal Comm 62.1609 (1).
Soil lateral loads: In discussing the 2003 changes to the soil lateral-load criteria in IBC 1610, Alan Wagner questioned what is meant by the included reference to "flexible" floor systems. Larry responded that generally any flooring other than monolithic concrete is consider flexible in restraining basement walls. Alan commented that the 2003 changes to IBC 1610 adequately incorporate Wisconsin’s Comm 62.1610 changes to the soil lateral-load criteria in the 2000 version of IBC 1610, and he consequently suggested repealing Comm 62.1610. Greg Bares asked whether the factor of safety for retaining walls, in 2000 IBC 1610.2, was deleted by the 2003 IBC changes, and discussion noted that the 2003 changes included moving that factor of safety to IBC 1806. A motion was made by Alan Wagner, seconded by John Rave, and passed unanimously, to repeal Comm 62.1610. Rain loads: John reported that problems are resulting from the new requirement in Comm 82, as referenced in Comm 62.1611, to not connect a secondary roof-drain system to a primary roof-drain system. There was agreement that a secondary system generally is intended to function as a bypass around a clogged intake of a primary system, and separating the secondary system from the remaining portion of the primary system is needless and costly. Sam Rockweiler agreed to research the rationale for the new requirement and report back at the next meeting. Earthquake loads: Larry reported that at training sessions he conducts, attendees frequently question whether the seismic requirements in Comm 61 to 65 can be deleted. Greg argued that they should. Greg noted the State owns about 8,000 buildings that have been built since the mid- to late 1800s without analyzing for seismic resistance, and none of them are experiencing corresponding problems. According to Greg, substantial taxpayer funds are now being expended on exorbitant related costs – such as with extensive redundant masonry – for a problem that does not appear to exist in Wisconsin. Greg questioned whether simplified empirical values could be substituted instead. John noted agreement for considering whether a lateral notion load could be substituted instead. Alan agreed the seismic requirements have created complications, and he described a construction project where he needed to analyze subsurface conditions to a depth of 100 feet, to accommodate adding a ninth story to an eight-story building. However, Alan cautioned that the 8,000 buildings Greg cited have all been built after the benchmark earthquake activity at New Madrid in the early 1800s. Mike Oliva explained that the seismic requirements are based on a 500-year period of risk, and on a presumption that a newly constructed building should have the same level of protection against that risk regardless of where in the nation it is built. According to Mike, retreating from the current seismic requirements would be a political or economic decision rather than a structural engineering decision. Greg responded that political decision-makers may depend on structural engineering experts for input in achieving common-sense requirements. John commented that training programs typically are presenting seismic requirements as protecting property rather than protecting life safety. Mike explained that seismic designs generally are based on protecting life safety, rather than on protecting property, because protecting property, such as at nuclear power facilities, involves higher level, more restrictive requirements. According to Mike, constructing a building to meet the seismic requirements means that at the 1-in-500-year event, the occupants would survive, but the building would no longer be useful. John explained that seismic analyses are routinely showing that for low-rise buildings in Wisconsin, wind loads are more restrictive than seismic loads, so deleting the seismic requirements for these buildings would only result in discontinuing the seismic analyses there. John added that this conclusion may not be true for high-rise buildings. Greg questioned the value that results from applying the seismic requirements. Steve Cramer commented the Council’s scope does not include redefining an acceptable level of safety, and he questioned whether the Council could develop a reliable, empirical, notion load that could be substituted for the seismic requirements. Larry questioned whether deleting the seismic requirements would result in increased property-insurance rates, as based on the building-code ratings established by the Insurance Services Organization. John and Bob Schumacher agreed that engineers who design buildings in other parts of the country have developed computer-based programs and systems to accomodate the seismic analyses without charging exorbitant fees. Steve asked whether other assistance could be developed for in-state designers. Larry explained that the Department has scaled back the corresponding details it requires for plans that are submitted for buildings where wind loads exceed the seismic loads, but designers are still responsible for performing seismic analyses for those buildings. Larry indicated he did not know whether additional assistance can be developed, such as for Seismic Design Categories B, C, and D, in IBC 1616. Bob suggested including a note in Comm 62 for informing designers of a US Geological Survey Web site that displays whether an inputted zip-code area is north or south of the 4 percent g contour line in IBC Figure 1615(2). Larry said a hyperlink to the USGS site is currently included on the Department’s Web site. A motion was made by John Rave, seconded by Dave Hyser, and passed unanimously, to replace the simplified, county-line based 4 percentg contour map in Comm Figure 62.162 with an informational note referencing the USGS Web site that displays whether an inputted zip-code area is north or south of the 4 percent g contour line in IBC Figure 1615(2). Larry asked whether the allowance in Comm 62.1615 (1) to ignore the 15 precent g contour line in IBC Figure 1615(1) should be retained, and there was consensus to do so. All of the remaining 2003 and 2004 IBC chapter 16 changes that were not addressed at the January 14th meeting were accepted.
2003
and 2004 IBC chapter 35 changes
Wisconsin
modifications to IBC chapter 21
2003
and 2004 IBC
section 1715 changes
The next meeting was set for March 11, 2005, at the same location and time, with an expectation of focusing further on IBC chapter 17. Friday, January 14, 2005, 9:30 a.m. to 3 p.m., Room 3B, Thompson Commerce Center , 201 West Washington Avenue, Madison, Wisconsin Council member attendance: Greg Bares Present; Steven Cramer P; David Hyser P; Michael Oliva Excused; John Rave P; Robert Schumacher (Chairperson) P; Alan Wagner E; Michael West P Guests: Paul Coats, American Forest and Paper Association
Commerce staff: Jack Miller P; Sam Rockweiler P; Larry
Swaziek P
2003
and 2004 IBC chapter 23 changes
2003
and 2004 IBC chapter 21
changes
Friday, December 3, 2004, 9:30 a.m. to 3 p.m., Room 3B, Thompson Commerce Center, 201 West Washington Avenue, Madison, Wisconsin Council Member Attendance: Greg Bares, Excused; Steven Cramer, Present; David Hyser, E; Michael Oliva, P; John Rave, P; Robert Schumacher, P; Alan Wagner, P; Michael West, P; Guests: Paul Coats – American Forest and Paper Association Commerce Staff: Steve Dobratz, Jack Miller, Sam Rockweiler, Larry Swaziek, John VanBuecken. Larry Swaziek opened the meeting with an introduction of newly attending staff and guests, and he summarized the reference materials that were transmitted to the Council prior to the meeting. The Council then accepted the draft progress report from the preceding, November 10 meeting of the Council. Mike Oliva commented that some of the Wisconsin modifications of the International Building Code address circumstances which are not unique to Wisconsin, and he asked whether the Department is attempting to have the International Code Council incorporate those modifications into the IBC. Mike suggested that if the ICC then chooses to not accept the modifications, and explains why, the Structural Council could then reconsider them. Mike indicated this additional review could further minimize the potential for Wisconsin having any inappropriate modifications of the IBC. Larry responded that the Department currently is not actively recommending IBC modifications to the ICC. Paul Coats commented that the ICC code revision process allows any individual to propose code changes, and Bob Schumacher commented that code changes which are proposed to the ICC by established organizations generally carry more weight. John Rave indicated that outside of Wisconsin, enforcement of building codes is generally more locally focused, and the ICC codes and code revision process are generally structured more toward accommodating that arrangement than Wisconsin’s state-driven code development and enforcement.
Larry reported that the 2000 IBC criteria which are not included in 2003 IBC section 1910.4.3, for anchor bolts in the tops of columns, are now included in section 7.10.5.6 of the current edition of ACI standard 318 – which is adopted by reference in the 2003 edition of the IBC. Alan
Wagner presented individual test graphs and a summary of
vertical head deflection versus applied axial compression loads, for
several recently conducted, significant pile tests; and he explained
how the data show that the 2003 text in IBC 1808.2.8.3 –
which
bases a pile’s load capacity on a settlement maximum of 0.3
inches during testing – is overly restrictive, because larger
settlements are acceptable for some circumstances. Alan showed that
each site’s appropriate controlling factor, which should be
applied to each of the pile tests instead of applying the 0.3-inch
limit, would indicate structural capacities ranging from 3 to 54
percent greater than the capacity allowed by the 0.3-inch limit. To
illustrate why use of these greater capacities is needed, Alan noted
that although 50- to 60-ton loads were typical for piles years ago,
today’s economics are resulting in 200- to 250-ton loads
which
are not uncommon. Alan explained that limiting the settlement to a
small amount is appropriate in some circumstances, where tight
tolerances are needed, but settlement is not always the most important
factor, and a similar overriding settlement limit is not similarly
prescribed for spread footings. In addition, Alan noted that performing
load tests for piles reduces uncertainty, which can allow use of a
lower factor of safety. Alan commented that for about 30 years, he has
used the Davisson Offset Limit, as currently reflected in section Comm
62.1807 (3) for these tests, without including an absolute, overriding
settlement limit, and he has found it to be rather accurate. A motion was made by Alan Wagner, seconded by John Rave, and passed unanimously, to delete the 2003 text in IBC 1808.2.8.3 that bases a pile’s ultimate load capacity on a settlement maximum of 0.3 inches during testing. Sam Rockweiler noted that the rule analysis which would accompany proposed adoption and modification of the 2003 IBC could explain why this text should be deleted.
Wednesday, November 10, 2004, 9:30 a.m. - 3 p.m., Room 3B, Thompson Commerce Center, 201 West Washington Avenue, Madison, Wisoncsin Council Member Attendance: Greg Bares – P; Steven Cramer – P; David Hyser – A; Michael Oliva – P; John Rave – P; Robert Schumacher – P; Alan Wagner – P; Michael West – P. S&B Staff: Steve Dobratz, Sam Rockweiler, Larry Stilen, Larry Swaziek, John VanBuecken. Larry Swaziek opened the meeting with an overview of the reference materials that were transmitted to the Council prior to the meeting. Larry explained that the Council would function as a specialty council for the Department’s Commercial Building Code Council, in reviewing potential changes to the structural requirements in the Wisconsin Commercial Building Code – chapters Comm 61 to 65 of the Wisconsin Administrative Code. Larry initiated a round of introductions, distributed a listing of council members and their corresponding representation, and followed with a review of the agenda. Sam Rockweiler distributed and summarized (1) an Advisory Council Manual produced by the Safety and Buildings Division, and (2) a projected timeline of the Council’s meetings, as coordinated with the Division’s other specialty councils and umbrella councils, for review of the corresponding 2003 to 2006 code changes from the International Code Council. Larry distributed proposed miscellaneous changes relating to the structural requirements in Comm 61 to 65, which the Department advanced to a public Hearing in March 2004 and which have an expected effective date of January 1, 2005. Bob Schumacher subsequently was elected as the Council chair.
2003
and 2004 changes to the International Building Code
IBC
Chapter 19
John questioned whether the 2003 IBC addition to section 1902.1 that defines prestressing steel should also address prestressing with other materials. Mike Oliva explained that the specificity to steel is intentional, because the corresponding requirements in Standard 318 from the American Concrete Institute address only steel. The current ACI 318 standard likewise incorporates the ASTM C 1157 specifications for cement, which resulted in deleting the C 1157 reference from IBC section 1903.2. Mike also explained that the summarized changes to IBC section 1908 address numerous modifications that have been developed for chapter 21 of ACI 318, as a precursor to those modifications appearing in the next edition of ACI 318. Bob Schumacher commented that the included criteria generally apply to regions that have higher seismic risks than occur in Wisconsin. Larry agreed to review whether the IBC 1910.4.3 criteria for anchor bolts in the top of columns were moved to another section, rather than deleted. Sam agreed to review whether the 2000 Wisconsin modifications to IBC 1914.4.2 and 1916.6 were directed at deleting a requirement to obtain an approval from a local building official. All of the other summarized changes to IBC chapter 19 were accepted.
IBC
Chapter 18
Sam noted the Department may delete the new criteria in IBC 1803.4 and 1807.1.2.1 - which address construction in flood areas - and the corresponding current criteria in IBC 1806.1.2.1, because construction in flood areas is not permitted in Wisconsin, and similar flood references elsewhere in the IBC have been deleted. Similarly, the new exceptions in IBC 1805.9 and 1808.2.23.2 for detached one- and two-family dwellings will likely be deleted, because those dwellings are within the scope of Wisconsin’s Uniform Dwelling Code rather than the Commercial Building Code, and similar references elsewhere in the IBC to those dwellings have been deleted. The Department may likewise review the new reference in IBC 1808.2.1 to local approval of piles designed as piers, but Mike West suggested that some of the other IBC references to local building officials may be helpful. Updating of affected section numbering in Comm 62 will also be needed, such as renumbering Comm 62.1807 to Comm 62.1808, to match the renumbering of IBC 1807 to IBC 1808. Mike West and Alan Wagner commented that alternate types of pier and pile foundations, such as geopiles and micropiles, are becoming more common nationwide, and although obtaining permits for them generally has not yet been a problem, codifying provisions for them in the future may be helpful. In reference to the distributed public hearing changes relating to the current criteria in Comm 62.1807 (3) for pier and pile loads, Alan explained that static analysis is an office review; dynamic testing is a field procedure that contributes to an economic design more so than to safety considerations, by enabling further identification of subsurface variations across a site; and static load testing is a more expensive field procedure. Alan explained that the Davisson Offset Limit, which is newly listed in IBC 1808.2.8.3.1 as a method for evaluating the load capacity of a pile, corresponds to the method currently prescribed in Comm 62.1807 (4). However, Alan noted concern that the corresponding new criteria in IBC 1808.2.8.3 – which bases the capacity on a settlement maximum of 0.3 inches during testing – may be overly restrictive, because larger settlements may be acceptable for some circumstances. Alan agreed to review and discuss the topic further at the next meeting, and recommended retaining the reduced safety factor in Comm 62.1807 (3) for nonoccupiable structures. Mike
West and Alan agreed that the modified references in IBC
1810.3.2 and 1810.4.2 to filing a pile-compliance certification with a
building official should be deleted, because the corresponding 2000 IBC
reference to that certification was deleted, and their legal counsels
continue to advise against it. Next meeting: The next meeting was set for December 3, at the same location and time. Links -- County Web sites || City/Town/Village Web sites || State Portal || Licensing and Permitting || Build Your Business The Department of Safety and Professional Services Safety and Buildings Division is an equal opportunity service provider and employer. If you need assistance to access services or need material in an alternate format, please contact us, 608-266-3151, TDD Relay dial 711 in Wisconsin or 800-947-3529. |