IIBEC 2020 Virtual International Conve ntion & Trade Show | June 12-14, 2020 D oddridge | 137 Specifying Fenestration – Understanding the Consultant’s Purpose in the Process Ron Doddridge, FMPC Moisture Intrusion Solutions 475 Fentress Blvd., Ste. A, Dayton Beach FL 32114 850-259-8520 • rdoddridge@moisturesolutions.net Ron Doddridge holds bachelor’s degrees in architecture, mechanical engineering, and business/religion. He has 24 years of experience in fenestration and building enclosure consulting. Most recently, Doddridge completed his professional certification as an AAMA Fenestration Master, of which there are currently only 105 in the world. 138 | Doddridge IIBEC 2020 Virtual International Conve ntion & Trade Show | June 12-14, 2020 ABSTRACT SPEAKER A testing technician from an accredited field testing lab is on site and is reviewing the project documents when he notices that the windows do not meet or exceed the building design pressure. He identifies the problem, determining that 200 windows must be removed and 800 windows on the project must be rejected, costing the project months and several hundred thousand dollars. With a proper understanding of the code requirements, this could have been avoided. This presentation will cover the current practice and how it is flawed. It will explore the requirements for the International Residential Code (IRC) and the International Building Code (IBC) as they pertain to fenestration product certification. The speaker will specifically delve into the IBC 2012 and the newer Section 1710, which requires that all windows and sliding glass doors be tested to conform to the North American Fenestration Standard (NAFS). The question, “What does this actually mean?” will be answered. This will be compared to the code requirements for storefronts/ curtainwalls. The presenter will look at the NAFS, fenestration specifications, and building design pressures based upon an ASCE-7 calculation, and complete the presentation by answering the question, “What is the role of the building enclosure consultant in this process?” CURRENT PRACTICE A project goes out to bid with plans and, hopefully, specifications. If we are blessed, the fenestration manufacturer actually sees the project specification and/ or the component and cladding chart (Figure 1) in the structural drawings. Fenestration submittals are then approved without much regard to detail—meaning that an architect may or may not be aware of the code requirement in the state that the project is in, which states that windows shall be tested to conform with the North American Fenestration Standard (NAFS). If the architect is aware, they may not truly understand the complexity involved. Therefore, twin and triple windows get approved that have performance ratings that either do not meet the minimum required in Section 2 of the window specification and/or do not meet the specific minimum of the component and cladding chart within the structural drawings. Windows show up at the project site and are installed. And then the test lab shows up to perform field quality control testing. The lead test technician discovers the issue and raises the flag, and time and money are lost. WHAT ARE IRC, IBC, AND IECC? Many may know the initialisms IRC, IBC, and IECC for International Residential Code, International Building Code, and International Energy Conservation Code; however, few may really know for certain if a particular structure’s windows fall under the IRC or the IBC. Even fewer actually know how the IECC defines structures or that the definitions are actually different from those in the IRC and IBC. Therefore, we will perform a little quiz to test the knowledge of participants at this presentation. What buildings fall within each of the IRC, IBC, and/or the IIECC? • Single family home – IRC and IECC residential • Duplex – IRC and IECC residential • Triplex – IBC and IECC residential (Figure 2) • A three-story singlefamily home – IBC and IECC residential • A three-story multifamily apartment building – IBC and IECC residential • A four-story multifamily apartment building – IBC and IECC commercial These are the basics, although a local municipality can get much more specific. Consequently, a triplex and a three-story single-family home actually fall within the requirements of the IBC. (As a side note, blower door testing of every unit is now required by the IECC residential sections for three-story multifamily structures and below. The IBC may vary slightly from state to state.) As an example, the Florida IBC version states windows must be tested to conform to the NAFS. Then there is a big “OR.” This little two-letter word actually messes it all up and creates confusion within the state. This confusion has extended outside of the state when developers, architects, engineers, and contractors actually think that a Florida product approval technically complies with another state’s building code. Typically, it does not. Florida product approval can be achieved with a NAFS product certification, but it also can be achieved with a Miami/Dade product certification. These two certifications are not the same. And many say that Miami/Dade is more stringent, when in reality, this is a relative statement that is not entirely based in fact. However, that is a different topic for another presentation. Specifying Fenestration – Understanding the Consultant’s Purpose in the Process IIBEC 2020 Virtual International Conve ntion & Trade Show | June 12-14, 2020 D oddridge | 139 Figure 1 – An example of a component and cladding chart from structural drawings based upon an ASCE 7 calculation. Figure 2 – A triplex that falls under the IBC and the IECC residential codes. IBC 2012 AND THE NEWER SECTION 1710 Windows Exterior windows and sliding doors shall be tested and labeled conforming to the AAMA/WDMA/CSA 101/I.S.2/A440 (i.e., NAFS). Exterior side-hinged doors shall be tested and labeled conforming to AAMA/WDMA/CSA 101/I.S.2/A440 or shall comply with Section 1710.5.2. (Figure 3). These two statements are actually vague if someone is not intimately familiar with the NAFS. Certification agencies, such as AAMA, WDMA, NAMI and Keystone have authority to product-certify windows and doors conforming to the NAFS. The state of Florida does not. Nor does Miami/Dade. Florida accepts the certification of either of these certification agencies to issue a Florida Product Approval or notice of acceptance (NOA). The authors of the NAFS, in cooperation with ASCE, issued a technical explanation bulletin in 2011 (Figure 4) clarifying how the minimum performance grade of a fenestration product was to be determined. In essence, one takes the highest negative load as calculated by the ASCE 7 zone 5 and rounds it up to the nearest 5-psf increment. This becomes the minimum performance grade of a fenestration product that should be installed into a building to ensure that all openings/zones are covered. If this were followed, there would never be a situation where hundreds of window/doors would need to be removed and replaced on a project, costing hundreds of thousands of dollars and countless hours. Windows Outside of the Gateway Test Size Almost every project has large windows and/or mulled configurations. So, how should this be handled when the NAFS does not specifically cover it? The answer is simply to perform project-specific testing with signoff by a professional engineer. This testing is not a complete reiteration of the product certification testing, but rather just air, water, and structural testing based upon the highest negative load that the ASCE 7 calculation revealed or the minimum performance grade that the fenestration specification identified. This testing will then follow the requirements of the NAFS for the performance class that the base product certification produced. This project-specific testing needs to be performed in the lab by a testing laboratory accredited to test conformance to the NAFS. Storefront/Curtainwall The minimum structural performance of storefront and curtainwall fenestrations has to be at least the highest negative load as identified by the ASCE 7 calculation as established in an ASTM E330 structural test. Technically, the IBC does not care if the storefront or curtainwall meets any air or water performance criteria. However, it is worth noting that the IECC does care about air leakage. And I would dare say that the owner of the project cares about its water performance. So, what should a specifier do? At a minimum, a specifier should require that the storefront and curtainwall have an ASTM E283 air leakage test, 140 | Doddridge IIBEC 2020 Virtual International ConveVEntion & Trade Show | June 12-14, 2020 Figure 3 – The IBC language pertaining to the NAFS requirements for windows and doors. Figure 4 – An excerpt from the technical bulletin from the authors of the NAFS and ASCE. an ASTM E547 water penetration test (or AAMA 501.1 dynamic water), and the ASTM E330 structural test. There are multiple other tests that really should be included, but this is the minimum. Lastly, storefront and curtainwall fenestrations can actually have a NAFS product certification as fixed windows. This is somewhat unusual, though, because it limits the size and performance grade. Generally, the only way that this is actually worth doing is to well exceed the fixed window gateway test size and include vertical and horizontal mullions. Exceed it to a point of covering what would cover most slab-to-slab heights and as wide as an air and water wall in a test lab can handle. This results in covering most opening sizes. Storefronts and curtainwalls spanning more than a single floor would not be worth attempting a product certification test on. NAFS There are four performance classifications: R, LC, CW, and AW. Each has its own specific requirements in order for varying types of windows and doors to be classified as any one of them. Additionally, the requirements are progressively more and more strict, respectively, with AW having the most stringent requirements. Additionally, the criteria to attain a particular performance class vary from fenestration type to fenestration type. This can get complicated, and the building envelope consultant does not generally need to know the specifics—rather only that the criteria vary and that an AAMA Fenestration Master or an accredited test lab can provide the specifics. Then there is performance grade (PG), which is often confused with design pressure (DP). This is understandable because that is what it was called before NAFS 08. According to the NAFS, a window’s DP is the combination of its positive and negative psf capability before the overload testing, and it will most likely be different afterwards. However, the PG is both the positive psf and negative capability combined into one singular value. So, if a window is assigned a PG of 40, this indicates that it has a positive DP of 40 psf and a negative DP of at least 40 psf. If it had a negative 50 psf, then the DP would be +40/-50. Yet the PG remains PG 40 (Figure 5). The NAFS does not allow for a higher positive DP than that of the PG. Just because Miami/Dade assigned a DP rating to a fenestration product, that does not mean that the same product at the same test size and configuration would attain the same PG rating. As an example, a window has a NAFS product certification rating of H-LC35 (current version would be LC-PG35-H), yet the Miami/Dade rating is DP +50/-50 (Figure 6). This is because in order to attain a NAFS performance rating, all required testing for the appropriate performance class and PG must pass. If one thing is not capable, then either the PG or the performance classification will be reduced. Additionally, Miami/Dade simply assigns a DP of “passing” an ASTM E330 structural test. There is a correlation between the DP and the lab water test pressure; however, there evidently is not a requirement to pass 15% of the DP in water resistance and still be able to attain an assigned DP. Using the example stated previously, that window product also identifies the lab water resistance to be 5.43 psf. This is certainly not 15% of DP 50. IIBEC 2020 Virtual International ConveVEntion & Trade Show | June 12-14, 2020 D Doddridge | 141 Figure 5 – Note in this photo, the performance rating is H-R6; however, it identifies a negative design pressure (DP) of 75 psf. Figure 6 – Note the DP of 50, but only a 5.43 psf water test in the lab, yet it has a LC-PG35 NAFS rating. The building enclosure consultant should understand that a NAFS product certification is required by code in almost every state today for windows and doors. A Miami/Dade certification means little to nothing towards complying with code outside of Florida unless it has been adopted in coastal areas for hurricane impact requirements. DETERMINE THE FIELD TEST PRESSURE Currently only two standards state how to determine the field test pressure for NAFS-certified fenestration products. They are AAMA 502 (Figure 7) for windows and doors and 503 for storefront and curtainwalls. For most test labs, these are the default standards. ASTM E1105 does not tell one how to determine the field test pressure, except to default to what is specified. If the specifier does not include a “Field Quality Control” section in the specification, an accredited field testing lab will default to AAMA 502 or 503. There are exceptions, and they can get confusing. If a fenestration product is not product-certified conforming to NAFS, then AAMA 502 cannot technically apply, because it says to start with the PG. Without a NAFS product certification, there is no PG, nor is there a performance class. A Miami/Dade certification does not assign a performance class or PG, rather a DP. It also only requires 15% of the DP for water resistance in the lab for all fenestration product types, whereas the NAFS requires 20% of the PG for AW-rated products. The AAMA 503 requires 20% from the DP storefront and curtainwall. Therefore, if you apply the AAMA 503 standard to a Miami/Dade-certified storefront or curtainwall product, then it will be tested in the field at or close to the lab test pressure. In this case, the “Field Quality Control” section of the specification is critical, and it needs to identify the field test pressure and the pass/fail criteria. Without it, the accredited field testing lab cannot legitimately determine the field test pressure. The alternative is to have the architect and storefront/curtainwall manufacturer agree upon an appropriate field test pressure and put it in writing to cover all concerned. If the storefront/curtainwall happens to have a NAFS product certification as a fixed window, and the size falls within the product certification test size, then AAMA 502 would apply because a performance class and PG would be assigned. If the storefront and curtainwall do not have a fixed window product certification, then once again, the specifier needs to identify in the specification the field test pressure and the pass/fail criteria. In the case of a project-specific test of either windows, doors, or storefront/curtainwall, two-thirds of the lab-tested water resistance pressure is appropriate for the field. THE ROLE OF THE CONSULTANT The building enclosure consultant should understand that a NAFS product certification is required by code in almost every state today for windows and doors. A Miami/Dade certification means little to nothing towards complying with code outside of Florida unless it has been adopted in coastal areas for hurricane impact requirements. The consultant also should know and understand that the minimum PG of a window or door on a project needs to meet or exceed the highest negative load according to the component and cladding chart or Section 2 of the window/door specification. If it is not covered in Section 2 of the window/door specification, then it simply defaults to the component and cladding chart. Additionally, Section 2 of a specification states the minimum required performance of a fenestration product, and it is not considered to be a default performance criterion. This means that just because a manufacturer does not want to allow a window/door to be tested according to the PG in the field, that does not mean that it is acceptable to then just test based upon the minimum required by Section 2 of the specification. The IECC also has been adopted in most states and has energy performance requirements for fenestration products within it. Unfortunately, the air leakage requirement within the IECC is stricter than the NAFS or Miami/Dade. As building enclosure consultants, we should point this out to the design team and request that a determination be made as to which takes precedence. Similarly, a swing door can have a level of water resistance, but that water resistance is drastically reduced or even eliminated when compliance with ADA is required. It is unfortunate, but you typically cannot have both. 142 | Doddridge IIBEC 2020 Virtual International ConveVEntion & Trade Show | June 12-14, 2020 Figure 7 – An excerpt from AAMA 502 (ref 5.3.2) that states to test in the field at two-thirds of the NAFS performance grade.
