When you replace a roof on a home that was built before the implementation of the statewide Florida Building Code on March 1, 2002, the nailing of the roof sheathing (decking) must be brought up to current standards for hurricane resistance as part of the installation of the new roof. I explained that often I experience "soft" decking after the shingles are installed and that as long as the roof holds my concentrated load it is not an issue. How to Prepare Your Home for Weather Extremes, DDA: Suburban Wildfire Adaptation | December 8-10, 2020. 300.4(E), "A cable, raceway, or box, installed in exposed or concealed locations under metal-corrugated sheet roof decking, shall be installed and supported so there is not less than 1 ½ in. We are using cookies to give you the best experience on our website. This website uses cookies so that we can provide you with the best user experience possible. The State of Illinois has not adopted statewide building codes. An existing roof should be evaluated based on design wind speeds and uplift loads that were in place at the time of permitting, and it is important to recognize the difference in the definition of the reference speeds. 1.2 Hail . While not all jurisdictions require a permit for roofing work, repairs or replacements will need to comply with the applicable code in effect at the time of the repairs or replacement. Homes with roofs built under the previous code might have spaces between the plywood decking. The International WUI Code is often adopted in these regions. The building code requires (in Section R502.2.2.4 of the 2009 IRC) that "Wood/plastic composite deck boards shall be installed in accordance with the manufacturer's instructions." Users should contact the authority having jurisdiction if there are questions. measured from the lowest surface of the roof decking to the top of the cable, raceway, or box. Nothing contained in this manual is intended or written to be used, nor may it be relied upon or used, by any person and/or business as legal advice. The ASCE 7 calculation procedures and the tables of design pressures are not reproduced here; please refer directly to ASCE 7 to obtain that information. My understanding is that after 2008 all roof decks had to be re-nailed when a new roof is installed. The ice barrier should extend from the lowest edges of all roof surfaces and extend at least 24 inches inward from the exterior wall line of the building. And it’s a construction feature that has changed over the years. Proper installation of snow retention systems is critical to achieve the intended performance. Both sets of tables include roof design pressures suitable for design of the elements identified above. Roof design wind pressures are determined using the wind speeds at the mean roof height of the building (i.e., average of the eave and ridge heights). Wind design requirements for specific types of roof covering are addressed in Chapter 15 of the IBC and Chapter 9 of the IRC. All of these codes are produced by the International Code … 1.3 Wind International Building Code ®, 2015 Edition (IBC®, 2015) September 17, 2018. The code provides the types of fasteners, the size of the fasteners and minimum penetration requirements. However, older buildings have been built to a variety of building codes or in some cases to no building code. There are no specific requirements for hail resistance of roofing products in model building codes. Do not vent exhaust air directly into roof … Building codes also require that many products and materials comply with applicable test standards, which are referenced in building codes. Compliance with test standards is verified by independent testing laboratories, and confirmation of compliance is typically noted on package labeling or direct product labeling. November 19, 2014, 10:38pm #1. They may also be included by owner’s choice. The IBC and IRC have specific requirements for roof construction where certain types of fire-resistance-rated walls that terminate at the underside of the roof decking. Manufacturers may also provide general recommendations for product uses in cold climates. below the lowest point of the metal decking. The ASCE 7 Commentary notes that the majority of buildings (perhaps as much as 60%–80%) have an exposure category corresponding to Exposure B. Not more than 25 percent of the total roof area or roof section of any existing building or structure shall be repaired, replaced or recovered in any 12-month period unless the entire roofing system or roof section conforms to requirements of this code. Wind speeds vary with height above ground and typically increase with increasing elevation. Vent exhaust air from kitchens, baths, and laundry to the outdoors with vent pipes that run through the roof cavity or attic to roof ventilators. Chapter 4101:8-9 Roof Assemblies. IRC or IBC) focus on weather protection, structural performance, roofing materials, and installation. Local building officials also have discretion in determining product approvals and their use, and in authorizing variances.Note: Ask to see ‘approved’ variances in writing, as some parties will claim they are allowed but do not have tangible proof. As per Sec. The exposure category may vary for a certain building depending on the terrain in a given upwind direction. All rights reserved. B. Other geometric discontinuities may have increased pressures as well, especially those at greater height on the structure. Roof repairs (not an entire roof replacement) does not require re-nailing of the entire roof deck however you would be required to re-nail any decking that is to be exposed and does not meet current requirements!! measured from the lowest surface of the roof decking to the top of the … Concrete Pavers are an example of noncombustible roof decks. The resulting variations are also reasonable for hurricane winds, but are likely non-conservative for thunderstorm outflow winds and tornadoes. Whether this applies in your case depends on whether your deck boards came with manufacturer's instructions. Decking R905.2.2 Slope Asphalt shingles shall be used only on roof slopes of 2 units vertical in 12 units horizontal (2:12) or greater. Asphalt shingles shall be fastened to solidly sheathed decks. Consult the manufacturer’s specific instructions for details. A cable raceway, or box shall not be installed in concealed locations in metal-corrugated, sheet decking-type roof. 311 COMMUNITY CONTACT CENTER. Asphalt shingles shall be fastened to solidly sheathed decks. See Section R302.2.2 of the IRC when roof decking needs to be replaced on townhouses. As per Sec. Contact an engineer or design professional for more information. The 311 service is a single telephone number for all non-emergency City of Albuquerque inquiries and services. Disclaimer: This manual has been prepared for informational purposes only. Installers should follow code requirements, energy standards, and manufacturer’s guidelines for the use of insulation in an approved roofing assembly, as they may differ across industries and product types. RICOWI, IBHS, and the participating roofing industry organizations expressly state that they have no liability, in negligence, tort, or otherwise, with respect to the use of any of the information and/or practices described in this article. [Comment: When a reference is made within this rule to a federal statutory provision, an industry consensus standard, or any other technical publication, the specific date and title of the publication as well as the name and address of the promulgating agency are listed in rule 4101:8-44-01 of the Administrative Code. measured from the lowest surface of the roof decking to the top of the cable, raceway, or box. The type, grade, thickness and installation of materials used for roof decks should conform to the requirements of the relevant local building codes of practice and regulations. Answer: False Explanation: While it is true that Sec. Some local building codes establish a threshold that requires the roof structure to be evaluated for conformance with the latest building code provisions when more than a certain percentage of the roof is being replaced or if remodeling exceeds a certain threshold. Code requirements change periodically as building codes are updated. When required, testing is in accordance with ASTM E108 or UL 790. • Solidly-sheathed roof decks: - Minimum 3/8-inch plywood sheathing, rated by The Engineered Wood Association (APA).1 - Minimum 7/16-inch Oriented Strand Board (OSB), rated by The Engineered Wood Association (APA).1 - Installed with minimum 1/8-inch and maximum 1/4-inch spacing at all panel edges and end joints. to outdoor applications, except where roof sheathing is exposed on the underside such as with open soffits. Roof sheathing shall be attached in compliance with the Florida Building Code, Florida Statue 553.844 and the Hurricane Mitigation Retrofit Manual. The requirements herein are applicable only to properties located seaward of the Intracoastal Canal on the Texas coastline (or seaward of the boundary authorized to be established by the Commissioner by the Insurance Code, Article 21.49, as amended). Standards are developed by independent laboratories and industry groups. Code interpretation: This section gives the parameters for the specific types of fasteners that are requirements for the attachment of asphalt shingles to the deck. The IBC allows non-classified roof coverings to be used on Residential Group R-3 (see IBC Section 310.5) and Group U (see IBC Section 312) buildings such as agricultural buildings, barns, carports, if the separation between the leading edges of the adjacent roofs is less than 6 feet unless otherwise required by local requirements, such as the International Wildland Urban Interface Code. Beginning with the 1995 edition of ASCE 7, the design wind speed basis was changed to a 3-second gust wind speed, which is different than the 1-minute average speed used in the Saffir-Simpson Scale for hurricanes. Minimum requirements for roof assemblies are found in Chapter 15 of the IBC, Chapter 9 of the IRC, and Chapter 7 of the IEBC. Design wind speeds are provided by the adopted building code, and are assigned based on the location and risk category of the building. Fire-resistance classification requirements are based on the type of construction and the building use group. 300.4(E), "A cable, raceway, or box, installed in exposed or concealed locations under metal-corrugated sheet roof decking, shall be installed and supported so there is not less than 1 ½ in. Wind produces different magnitudes of pressure acting on the surfaces of a building due to the building’s geometry, and can create small areas of higher pressure on a surface while at the same time other areas on the same surface experience lower pressures. Building codes, such as the IBC, reference ASCE 7, Minimum Design Loads for Buildings and Other Structures, for the determination of design snow loads on buildings. 3. Early maps used what is called the fastest-mile wind speed as the reference standard design wind speed. C&C design pressure coefficients and the associated roof zones in ASCE 7-16 reflect results of a major reanalysis of databases produced from wind tunnel results. For example, the State of California has requirements for certain types of roof coverings, vents, and/or openings in areas of the state prone to wildfires that fall under the WUI restrictions. below roof decking. In areas where the average daily temperature in January is 25°F (-4°C) or less, solid sheathing is required on that portion of the roof requiring ... Los Angeles Residential Code > 9 Roof Assemblies > R905 Requirements for Roof Coverings > R905.8 Wood Shakes > R905.8.1 Deck Requirements > R905.8.1.1 Solid Sheathing Required. The IRC Section R902.1 requires Class A, B or C fire-resistant roofing only in jurisdictions designated by law, or where the edge of the roof is less than 3-feet from the property line. (i.e. Again, if this type of decking is discovered during the tear off of the roof shingles, a thorough inspection must be made to make sure that it is in good overall condition and that the gaps between the individual boards does not exceed ¼” to ½”. In moderate hail zones, recover of an existing roof is often not permitted (please refer to the jurisdiction having authority). The user assumes the sole risk of making use of the information provided in this manual. Circuits shall be run perpendicular to the roof pen - etration point to supports a minimum of 25 cm. IRC requires shingles to be fastened to solidly sheathed decks ('09, 905.2.1). Refer to the jurisdiction having authority to determine if snow retention systems are required. The roof system and the building must be designed to resist loads from retained snow. 300.4 (E) requires raceways, cables, or boxes to maintain a 1-½ in. September 2017 Repairing My Roof after a Storm The storm damaged my roof. Inspection Requirements **You can now request an inspection online, by clicking the link, " Inspection Request Form " and completing the form ** (Please be advised that an inspector will confirm the date and time of the inspection requested) Have any of you guys found or developed any more specific criteria for when a roof deck should be replaced? Check back often to see the most up-to-date edition of the guide. C&C loads are used to design roof sheathing elements and their attachment to the roof framing as well as secondary members such as purlins, rafters, and truss top-chord members between panel points. This also means that when re-roofing there are opportunities to improve the roof’s wind performance by following best practices for roof-to-wall and sheathing attachment. IBHS translates science into action to inform the insurance industry, prevent avoidable suffering, strengthen our homes and businesses, and support thriving communities. It will support roof loads for most situations and is the standard for most roof applications. New roofs must comply with the 2015 IECC. The International Energy Conservation Code (IECC) is of particular importance to low-slope roof design due to its R-value requirements, which affect the amount of insulation that has to be included in roof assemblies. The 311 Community Contact Center is a centralized call center for the City of Albuquerque. Roof sheathing conforming to the provisions of Table 2304.7 (1), 2304.7 (2), 2304.7 (3) or 2304.7 (5) shall be deemed to meet the requirements of this section. Vent exhaust air from kitchens, baths, and laundry to the outdoors with vent pipes that run through the roof cavity or attic to roof ventilators. Many manufacturers limit the use of the Ice barrier to 24 inches maximum from the exterior wall line, or require special ventilation if the ice barrier extends inward for more than 24 inches. Typically, plank decking. You can find out more about which cookies we are using or switch them off in settings. Listed below is a checklist for building construction requirements per the 2016California Residential Code, Section 327: Roofing – Section R327.5 . A "4:12 roof slope" means the roof rises 4 feet for every 12 feet of horizontal roof span. Roof decks shall be covered with approved roof coverings secured to the building or structure in accordance with the provisions of this chapter. For buildings with low-slope roofs (less than 2:12 slope), the wind speed at eave height is used. Panel applications shall meet the minimum requirements of the applicable building code and comply with the manufacturer's recommendations. Generally, design wind speed maps from ASCE 7 are adopted into the model building codes during the next update cycle. R905.2.1 Sheathing requirements. d) 2 in. Building Code Roof Decking question. Article 300 covers general wiring requirements for wiring methods and materials for all installations. Verify any local requirements with the authority having jurisdiction. Consequently, building codes allow different approaches for determining design wind loads for these systems. For buildings constructed in accordance with the IBC, the requirements are fairly complex and depend on the type of construction, use group, and rating of the wall, as well as fire separation distance between buildings and the construction of the roof assembly. Therefore, it is more likely that the roof-to-wall connections, roof sheathing attachment and roof covers are under-designed, than is the roof structure when compared with current design loads and construction practices. The nominal size of wire used with a 100 amp service shall be No. The IRC uses Exposure B as the default wind exposure category, while the IBC uses Exposure C as the default wind exposure category. Similarly, if a roof is recovered, the existing roof covering layer must be in good condition to support the new covering. ASCE 7 wind loads are specified for the Main Wind Force Resisting System (MWFRS) and for Component and Cladding (C&C). For the purposes of roofing, cold climates are those in which ice dams form and snow retention may be needed. Noncombustible Roof Decks. This has been the practice of the departments I have worked in out here and frankly most homeowners would go ballistic if I mentioned replacing the roof sheathing. Some homes being built after 2002 the builders started to use the new nailing and some AHJ required new nailing on new builds. sheet roof decking, shall be installed and sup - ported so there is not less than 38 mm (11/2 in.) Intake and exhaust vents are the preferred method of attic ventilation. Building construction codes effective March 1, 2017 or as noted otherwise. permitted under the 2004 code or newer). Most other roof system requirements in the building codes (i.e. In such situations, an ice barrier is required to prevent dammed meltwater from penetrating through the roof assembly and into the interior spaces. [Comment: When a reference is made within this rule to a federal statutory provision, an industry consensus standard, or any other technical publication, the specific date and title of the publication as well as the name and address of the promulgating agency are listed in rule 4101:8-44-01 of the Administrative Code. Once the model building codes have been updated, the updates will begin to make their way into locally adopted codes and standards. Roof drainage water from a building shall not be permitted to flow over public property. Please report broken links or other issues to Simon Kellogg ([email protected]). Building Codes for roofing reqiure a minimum 1x4, and the spaces between battens should not exceed 3 1/2 inches (Figure 2-46 - wood shingles over spaced sheathing, and Figure 2-47 wood shakes installed over wood sheathing are illustrated below). Calculated values in ASCE 7 are based on factors such as: ground snow load value; importance factor based on use or occupancy; wind exposure; roof slope and shape; roof obstructions; thermal factor related to expected roof temperature; and snow drifting. 706.7 When a roof covering on an existing site‐built single family residential structure is removed and replaced, the following procedures shall be permitted to be performed by the roofing contractor: (a) Roof‐decking attachment shall be as required by Section 706.7.1. Roof Decking . These design approaches are not included in this document but can be reviewed in the IBC and in other industry literature. R905.2.1 Sheathing requirements. It is understood that the Contractor(s) awarded a contract will comply with the most stringent industry-standard construction requirements and … A roof replacement is the process where all existing layers of roof covering are completely removed down to the roof deck before a new roof covering is installed. The minimum service entrance shall be 100 amperes with a 3-wire, 120/240 volt, single-phase service with a grounded neutral. The intent of TMCS is to remedy health and safety defects, particularly life threatening deficiencies. The manufacturer of the products should be consulted for the proper number, location and fastening requirements to resist the loads associated with the anticipated snow accumulations. Users of this manual are strongly urged to follow accepted safety practices, refer to applicable local building codes and standards, and relevant manufacturers’ instructions for appropriate technical requirements, and to work with a qualified professional in order to operationalize the information contained herein. You cannot have a wood roof deck over 20% of the roof area in NYC. International Code Council (ICC) Online Code Library. A cable, raceway, or box installed under metal-corrugated sheet roof decking shall be supported so the top of the cable, raceway, or box is not less than _____ from the lowest surface of the roof decking to the top of the cable, raceway, or box. I understand that the HVHZ is different, I am asking about everywhere else in the … International Residential Code (IRC) 2006 | Section R905 This guide highlights and clarifies the recognized minimum standards in the IRC base building codes for asphalt roof installation. Roof slopes between 2:12 and 4:12 can use shingles, but require roof application techniques to take into account Building codes may provide specific instructions and limitations for conditions when recovering is permitted and when replacement is required. Local jurisdictions may have additional requirements or design criteria for roofing assemblies in cold climates. Reroofing requirements Building codes provide specific guidance for reroofing projects by Mark S. Graham The code includes several exceptions to its requirements Specific building code requirements apply to roof system re-cover and replacement proj - ects. Local building departments identify areas where there has been a history of ice forming along the eaves, and should be consulted for additional cold climate requirements. Decking is the layer of plywood between the shingles on your roof and its structure. This includes structural components such as roof sheathing or rafters, or roof cover components and the connections of these elements. 1504.4 Concealed piping. Roofs are framed with rafters or trusses, which are rafters joined by internal braces so they install as a single component. several key changes to the requirements for roof assemblies. Minimum Insulation R-value Requirements by State: Non-Residential, Above Roof Deck. clearance from the lowest point of the metal decking, there is an exception that permits … State and local jurisdictions frequently make amendments to the model building codes, and as the authority having jurisdiction, these will represent the required code for a particular area. Your roof covering and the deck beneath it are your home’s first line of defense against high winds, rain, and hail. A cable, raceway, or box installed under metal-corrugated sheet roof decking shall be supported so the top of the cable, raceway, or box is not less than _____ from the lowest surface of the roof decking to the top of the cable, raceway, or box. Please refer to the ventilation manufacturer for product installation and limitations. of roof decking or sheathing except where directly below the roof surface covered by PV modules and associated equipment.