Roofing Florida September 201110

Insight into how the Metal Roofing Industry can benefit from

the Upcoming Code Changes

Turning Change into Profit

On March 15, 2012, the fun and frustration of learning how to do business under a new set of buildingcodes will begin. Although publication of the code is scheduled for October 1, 2011, it is not until thisdate that the 2010 edition of the Florida Building Code (FBC) goes into effect. Innovative manufacturersof metal roofing systems and other affiliated products and services, along with the contractors incharge of its installation, are already looking for ways to turn thischange into innovations and profit. If you’re eager to catch a glimpseof what’s to come, you can view drafts of the code in supplementformat by visiting the Florida Building Commission (theCommission) and the Florida Department of Community Affairs(DCA) website at http://www.dca.state.fl.us/fbc/index.htm.

The 2010 Unified Florida Building Codeconsists of two sections:

•The High Velocity Hurricane Zone (HVHZ) – anexclusive two-county area that includes Miami (DadeCounty) and Fort Lauderdale (Broward County)

•The Non-HVHZ, which consists of the other65 counties – commonly referred to as thestate sectionAn HVHZ classification does not describe the wind design velocity of a certain section. For instance, the Florida Keysand Palm Beach County have equal or higher wind velocities than those found within the two HVHZ counties wherestringent building codes mandate an extensive product approval process that includes compliance with the Notice ofAcceptance criteria and the limitations of NOA use. However, according to the ASCE 7 national standard, all of Floridais in the Hurricane Prone Zone for wind design.

Building the New Codes and Tracking the Changes

The 2009 International Building Code was used as the foundation for the 2010 Florida Building Code in Non-HVHZareas but the finished product includes numerous Florida specific modifications. The HVHZ code section is based onthe former South Florida Code with new modifications and is compatible with the unified code. A major feature uniqueto Florida is the statewide Florida Statute (FS 553.842) that requires a local or state product approval with “productsand systems which comprise the building envelope and structural frame for compliance with the structuralrequirements of the Florida Building Code”. (FAC Rule 9N-3)The most substantial and wide-ranging change in FBC 2010 is the adoption of design standard ASCE 7-10. As a sidenote, this change is scheduled for inclusion in the IBC’s 2012 edition. Just wait until you see the three-state, wind-velocity contour maps with speeds 20 to 40 m.p.h. higher than the previous single map plus the reappearance ofcoastal exposure D! But, before you say some bad words in front of the kids due to the overwhelming prospect oftrying to make sense of these new regulations, read on . . .With the exception of areas found approximately within a mile of the ocean’s shoreline or other undefined large bodiesof water, the bottom line dictates that the design uplift pressures for roofing be the same or slightly lower. That's right,the same or lower for B or C exposures! Based on preliminary calculations, roofs in the D exposure appear to registerin a 10-22 percent higher range. How you get from higher velocities to about the same design uplift pressures is byusing a series of charts, formulas, definitions and calculations. (Could be one of the reasons the current edition ofASCE 7-10 is now almost double the number of pages than the previous edition.) It is an analytical methodology thatonly an engineer like me finds exciting. If you prefer a much simpler chart, Table R301.2(2) in the residential codevolume and RAS 127 or RAS 128 in the HVHZ Test Protocol volume are code prescriptive uplift pressures that can be

By James L. Buckner, PE, SECB, President of CBUCK Engineering

Reprinted with Permission by: ROOFING FLORIDA Magazine

September 2011 Roofing Florida

Continued on page 12

used for estimating purposes and for permitting within theconditions of use. If you plan on working on larger jobs/commercial projects and/or want more precise lowerdesign values, you can take classes, buy software, DIYor find a good engineer to work with you.

Tools to help you get from there to here . . .

You must know the risk category definitions in order toselect the correct wind velocity map. Counties shouldhave large-scale maps of their jurisdiction, which will helpdetermine a specific project’s location relative to itsdesign contour. Wind velocity maps for Risk Category Iare seldom applicable and apply to areas with a low riskto human life in the event of failure. Category II is formost of the ordinary buildings not found in anothercategory. The map for both III and IV has the same riskfactor. Buildings whose failure poses a substantial risk tohuman life are Category III and those designated asessential facilities are Category IV. Install to an incorrectmap and you risk a redo (by the way, a redo almostnever makes a profit). A full page of details can be foundin Chapter One of ASCE 7-10 on page two. At this time, Ido not know where these definitions can be found in FBC2010.

FBC 2007 versus FBC 2010A General Comparison of Roof Uplift Pressures

The charts on page 12 are only for general relativecomparisons and based on posted, in-progress code

modifications not yet officially published. Both are typicalresidential buildings with a mean roof height of 25 feetand a 4:12 slope. The first chart illustrates thecalculations for a Risk Category II project located in themiddle of Florida and the second illustrates those for usein Miami-Dade for Category II.

Change for Profit – Opportunity for a Two-for-One Special

These prescriptive wind tables provide good ballpark upliftnumbers for manufacturers to use when reviewing theirproduct’s approved uplift resistance. If you use theserelative comparisons based on yet to be published codemodifications, some systems might be more competitivein the market place, with additional assemblies tested tohigher resistance for the edge and corner zones. Nowwould be a good time to economize a two-for-one Floridafee. Additional tested and evaluated models can beadded to an existing Product Approval number as part ofthe recertification to FBC 2010 for one revision charge.Manufacturers with existing Florida Product Approvalswill need to demonstrate compliance with the new editionof the code by the effective date or risk being rejectedby local building departments according to an email sentby the DCA on July 13, 2011. Demonstration ofcompliance should show if the edition change hasaffected the product and state the appropriate code

11

Reprinted with Permission by: ROOFING FLORIDA Magazine

Roofing Florida September 201112

Design Uplift Pressures PSF per RAS 127

Miami – Dade

Field (Zone 1)Edge (Zone 2)Corner (Zone 3)

FBC 2007 – HVHZ

(w/ 2009 Supplement) Exp. C3

FBC 2010 – HVHZ

Exp. C4

Roof Zones

- 48.8- 85.0- 125.7

- 47.3- 82.3-121.8

FBC 2010 – HVHZ

Exp. D4

- 40.9- 71.3-105.4

3. Basic Wind Speed Using FBC 2007, HVHZ: V3s

= 146 mph 4. Ultimate Wind Speed Using FRC 2010:VUlt

= 185 mph

1. Basic Wind Speed Using FRC 2007: V3s

= 110 mph 2. Ultimate Wind Speed Using FRC 2010: VUlt

= 140 mph

Design Uplift Pressures PSF per Residential Code Table R301.2(2)

Mid-Florida

Field (Zone 1)Edge (Zone 2)Corner (Zone 3)

FRC 2007 (w/ 2009 Supplement)

Exp. C1

FRC 2010

Exp. C2

Roof Zones

- 26.2 psf- 45.5 psf- 67.3 psf

- 26.8 psf- 46.8 psf- 69.2 psf

CHANGE INTO PROFIT continued from page 11section number(s) or standard(s) of the new code edition.The good news is that this process is usually way lessexpensive than the initial approval. But, as with mostcode issues, there are several paths to choose from,each with their own pros and cons . . . The do it yourselfpath is the least expensive but beware – there are noallowances for edit changes. The documents you preparefor design professionals, contractors and building officialsmay only reference old code language with no mention ofthe new code. The second path, the Revision Method,only costs $400 more per approval number for the statefee, plus a modest fee from the evaluator to revise andedit the report. This additional expenditure often yieldsgood returns because the reports are very clear to theend users as to specifics regarding current code. Therevised report can state FBC 2010 code references alongwith any new clarifications. Visit the FBC’s websitewww.floridabuilding.org for further information.

The NOA in the FBC

A Miami-Dade NOA is the main product approvalcertification in the HVHZ code section. It can also beused as the evaluation/certification report for a FloridaProduct Approval. The renewal cycle for NOAs is everyfive years. It may be specified as a project requirement in

the other 65 counties and some designer/owners willstipulate their use when specifying above-code minimumconstruction. Since most building officials will enforce theNOA requirements if it is the approval document used forpermitting, you need to proceed with caution. Forinstance, did you know that most or all Miami-Dade metalroofing NOAs reference RAS 133 in the system’slimitation, which regulates the maximum length of steelpanels to 45 feet and aluminum panels to 32 feet?Because of this and many other stipulations, it’simperative that you know all the limits of use and codesections that are referenced in the more restrictive HVHZareas before using a NOA in other areas of the state.Manufacturers of metal products used in buildingenvelope systems, may be interested in several productapproval changes found in the new code. Since soffitfailures were documented to be a cause of considerablewater damage after recent hurricanes, the new codestates that soffit materials and systems shall be subjectto state or local product approval. Permanently markedlabels are required for individual manufactured soffitpieces. In addition, a product that is integral with, or on,an approved roof system needs approval. If you are a roofmanufacturer issuing material and /or weather tightness

Reprinted with Permission by: ROOFING FLORIDA Magazine

September 2011 Roofing Florida

James L (Jimmy)Buckner, P.E., SECB

TURNING CHANGE INTO PROFIT continued from previous page

warranties, you might want to evaluate accessories such as solar photovoltaics, PV laminate, solar thermal collectors,tubular daylighting devices (TDD) and rooftop structures/equipment for compatibility with your system and code

attachment compliance.

Turning Change into FUN and Profit

As far as I’m concerned, the real fun and action begins when you bring design elements,manufacturing techniques, field construction and code regulations together to complete onesuccessful metal roofing project. Having been a contractor in Atlanta for over 20 years, I knowwhat an ordeal it is to bid work based on often-sketchy plans. I’ve juggled the intricacies ofdesigning a strong, structurally sound job while filing multiple permits, managing the fieldconstruction and collecting money so that perhaps at the end of the day, I might show a profithigher than the interest rate on my savings account. Now that I’m a consultant, offering tips and

pointing out potential issues, such as those in this article and listed below, are a rewarding part of the work I do.

After an examination of the new code, I discovered a few items I think contractors might find useful . . .

•Metal recover over an existing roof is not suitable for all projects but it is allowed and has some added code language that

includes several important conditions. One code section that addresses recovering versus replacement is locatedin a volume of the existing code, Section 611.3. It states that the existing roof cannot be water soaked. TheHVHZ section spells it out clearly “Complete and separate roofing systems, such as standing-seam metalroof systems, that are designed to transmit the roof loads directly to the building’s structural system and thatdo not rely on existing roofs and roof coverings for support, shall not require the removal of the existingroof covering.” Analyze the project to select the best roofing option.

•As mentioned previously, the permit applicant needs to demonstrate that the accessories attached to or on the primary

building envelope are installed to meet the wind pressure loads for that specific project. Products with Florida ProductApprovals or Miami-Dade NOA’s that provide more resistance than the design wind uplift are usually the easiest typesto use in these situations. If a product needs more resistance, or theproduct does not have a state/NOA approval, site specific engineering isan allowed method. Expect to be charged for the additional time neededfor the design and approval of these local site-specific designs.

•In various sections, the new code addresses the product approval and labeling

requirements for soffits and solar products. Be warned, building officials will beramping up their enforcement of wind load resistant codes on roof topstructures and equipment to comply with these modifications.

•Due to a recent report found in a Building Officials Association of Florida (BOAF)newsletter on recently reported cases of forged product approval documents, it is a

best practice to download your certifications for each job directly from the product

approval web site. This will insure that you are using the current model for eachproduct and allow the building official easy access to the web path you used to verifyproof of this approval.

If you develop a mindset that perceives change as an opportunity for growth, then profits are sure to follow.

As we approach the final date for the implementation of the 2010 Florida Code, it's my hope thatthe metal industry will grab this opportunity to not only adjust to working under these newregulations but create innovative ways to show case its products and revamp the methods fortheir use and application.

About the Author

James L (Jimmy) Buckner, P.E., SECB is President of CBUCK Engineering. CBUCK specializesin developing test programs, evaluating products/assemblies to enhance their marketability andthen expediting code related product approvals for manufacturers of building products. CBUCKhas established a reputation for efficient site-specific wind design on major projects as well asobtaining timely One Time Approvals for unique applications.

13

Reprinted with Permission by: ROOFING FLORIDA Magazine