This is important because the osha definition is used as a basis for implementing low slope fallprotection measures, such as warning. Download it once and read it on your kindle device, pc, phones or tablets. Asphalt shingles are an acceptable roof covering for steep slope roof decks. Most low slope roof membranes have three 3 principal components. Special thanks to the ontario industrial roofers contractors association and the sheet metal workers international association for their contributions to the creation of this manual. Nov 27, 2018 the disadvantages of a low slope roof are the following.
A guide to vapor retarder design in lowslope roof systems gaf. Low slope roofing products are those primarily intended for roofs with slopes of 3. Design professionals frequently specify the minimum codepermitted slope with little, if any, consideration of the resultant valley slope created by the intersecting planes figure 1. Waterproofing layer or layers the weatherproofing component is the most important element since it keeps water from entering the roof assembly 2. With the exception of foam and metal, all low slope systems can be incorporated into protected membrane roof pmr designs. See nrca roofing and waterproofing manual, the manual of low slope roof systems griffith and fricklas, and roofs baker. Therefore, certainteed cannot assume responsibility for. Structural metal panel roof systems can be used in steep slope applications but this is the only metal roof system that can be used in low slope applications.
Components that form part of the vegetated roof systems assembly providing unimpeded flow of water on the roofs surface to the roofs drainage points. This manual replaces all previous versions of the cedar shake and shingle bureau design and application manual for new roof construction. Jul 01, 2006 manual of low slope roof systems, 4th ed. Insulating lowslope residential roofs greenbuildingadvisor. Shingles should not be installed on roof decks with slopes lower than this. Glossary of low slope roofing terms lsg 3 updated august 2017 drainage layer. Finding the right products for your low slope roof. Download for offline reading, highlight, bookmark or take notes while you read manual of low slope roof systems. Coach general description 032407 chapter 3 page 3 bluebird vagabonds handbook turning radius curb radius. Building offsets are common and create intersecting planes that contribute to drainage issues for low slope applications. The purpose of this guide is to provide some fundamental information and. Structural metal panels are designed to inhibit the ability of water to enter the system at laps and other joints by the use of sealant or anticapillary designs used in the seams.
Griffin mcgrawhill education for decades, this manual has been the most widely respected guide. Numerous and frequentlyupdated resource results are available from this search. For decades, this manual has been the most widely respected guide to designing, constructing, and maintaining low slope roofing systems. The nrca roofing manual membrane roof systems nrca roofing manual. The manual recognizes some building codes and man ufacturers allow for the application of watershedding roof systems on slopes as low as 2. Steep slope roof decks are decks that have a slope at least 2 51 mm of rise per 12 305 mm run of roof span. Manual of lowslope roof systems fourth edition building. The manual is a widely respected guide to designing, constructing, and maintaining low slope roofing systems. Residential low slope roofing can generally be divided up into two broad categories. A low slope roof is one that has a slope of less than 3in12. Bur a continuous semiflexible membrane comprised of plies of organic or inorganic asphalt saturated felts adhered into full interply mopping of bitumen. Enclosed attics and enclosed rafter spaces formed where ceilings are applied directly to the underside of roof rafters shall have cross ventilation for each separate space by ventilating openings protected against the entrance of rain or snow. The conservation technology epdm roofing system offers any homeowner, builder, or roofer the means to reliably and permanently waterproof low slope roofs, rooftop decks, and green roofs.
Roof failure causes in depth and specific methods for avoiding them. Reliable information about the coronavirus covid19 is available from the world health organization current situation, international travel. If something damages your low slope metal roofs, then the impact also occurs in other parts of the roofing system. Arca divides roof systems and materials into two classifications.
A roof that is nearly flat or slightly pitched is called a flat roof or low slope roof no roof should be dead flat because it must have at least a slight slope to drain. Once the low spot has been filled in, evenly broadcast 16 grit silica sand or colored granite roofing granules into the wetuncured slope mix until refusal. Plus the manual contains more great info on the pitfalls of ventilating low slope roofing and the authors do a great job hammering home the importance of. The term replacement is used when the existing roofing system is to be. As in all construction work, paying attention to the little details can make all the difference between a longlasting, troublefree project and one that results in callbacks and early failure never a good option with a new england roof. Roofslope roof leveling compound powered by plidek. Use features like bookmarks, note taking and highlighting while reading manual of lowslope roof systems.
The average slope is the slope of a line from the low end support to the point of maximum deflection for a member. In the absence of adequate ventilation, a vaporair retarder is recommended to limit the movement of moisture into the roof system. Nrca makes this recommendation in recogni tion of the fact that rapid and complete drain age is essential for watershedding roof systems. In this article, roofing specialist dyami plotke describes his process for getting the details right so that a low slope epdm roof can last for 20 years or longer of leakfree service. In this article, roofing specialist dyami plotke describes his process for getting the details right so that a low slope epdm roof. Roof system types roof systems and materials generally are divided into generic classifications. The premier guide to commercial and industrial roofs for decades, this manual has been the most widely respected guide to designing and specifying low slope roof systems.
Apr 12, 20 the manual of low slope roof systems also has valuable information on inverted irma or protected membrane roof pmr systems that readers in more extreme climates may find interesting. Manual of lowslope roof systems mcgrawhill education. Steep slope roof systems is one of the four volumes which make up the roofing manual and is sold separately. Low slope roofing includes water impermeable, or weatherproof, types of roof membranes installed on slopes less than or equal to 3. A solar electric or hot water system can be the feather in your roofs cap. Griffin, published by mcgraw hill professional which was released on 17 february 2006. Lowslope roofs rei engineers building enclosure consulting. Designers frequently select low slope roofs when the roof is expected to accommodate rooftop equipment.
As the codepermitted l120 or l180 ratios are approached, the deflection curve extends below a horizontal datum to create a bowl. Roof air conditioning this system includes 2 two,500 btu air conditioning units with condensate drain systems. Builtup, polymer modified bitumen, singleply, spray polyurethane foambased and structural metal panel roof systems fit this category. Shingles are to be used only in areas approved by state and local building codes. Products purchased from third party sellers are not guaranteed by the publisher for quality, authenticity, or access to any online entitlements included with the product.
Surfacing surfacing of membrane protects it from sunlight and weather. It is essential to roofing contractors across the united states. Lowslope roofs design solutions for building codepermitted low slope. Chapter 15 in the 20152018 international building code ibc contains installation guidelines that permit a design slope of 14 in 12 for certain types of roof covers. The latest edition supersedes the aia manual of built up roof systems 1982 and the griffinfricklas third edition 1996, both now out of print. If you want to learn how to build a deck on top of a flat roof, read the article decking over a roof. It remains unique the only working handbook that treats all topics in roof design, from fundamentals to roof systems. Mar 28, 2017 to provide the roofing industry with the most comprehensive information about the design, materials and installation techniques applicable to all materials used in steep slope roof system applications, nrca has released the nrca roofing manual. Lowslope roofs design solutions for building codepermitted low slope applications that cause ponding water. In most cases we custom fabricate a single sheet the size of each roof, eliminating the risks associated with field seaming. Refer to the maintenance manual for detailed operating instructions.
Lowslope roof system types roof asset learning center. Glossary of low slope roofing terms lsg 2 updated august 2017 cant strip. A triangular shaped strip of wood or fiberboard that forms a bevelled transition for membranes between the horizontal to vertical planes. In some cases, a homeowner may choose an option such as a selfadhering membrane residential roof system, which offers the multilayer protection of a membrane roof, with the traditional granule look of a shingled or builtup roof. Glossary of low slope roofing terms vegetated roof systems. The manual of low slope roof systems fourth edition. He is a consulting engineer specializing in roofing and energy conservation and a former senior editor for mcgrawhills engineering newsrecord. Low slope roofs are rotting was an article published in july 2016 in interface journal about three buildings in a northern united states climate experiencing premature deterioration of their roofs due to moisture condensation within the roof assembly.
The manual s reroofing section offers guidelines for determining. Shipping may be from multiple locations in the us or from the uk, depending on stock availability. Nondestructive testing for the purpose of locating breaches in the. Design solutions for building codepermitted low slope applications that cause ponding water. The upper ply of two ply modified bitumen membrane which is fully adhered to the base sheet. Oclcs webjunction has pulled together information and resources to assist library staff as they consider how to handle coronavirus. For decades, this manual has been the most widely respected guide to designing, constructing, and maintaining lowslope roofing systems. Members optimized to a codepermitted deflection ratio further reduce the average slope and may create a negative slope or a bowl condition at the low end that limits or prevents free drainage. Reinforcement reinforcement adds strength, puncture resistance, and dimensional stability 3. Historical background of contemporary roof systems chapter 10. Just like different types of roofs, without proper and routine inspections, low slope roofs are prone to leaks and possible collapse. Download manual of low slope roof systems books now. Prior to the midtolate 1970s, almost all lowslope roofs were asphalt or coal tar builtup roofs.
A triangular shaped strip of wood or fiberboard that forms a. In either case, find a professional roofing contractor experienced with low slope roofs and these specific products. Flat roofs are difficult to install properly, and as a result, many dont last for anything close to the life span theyre capable of achieving. Gaf offers roof guarantees for a fee for roofing system specifications published in this manual when installed by gaf factory certified lowslope roofing contractors. Roof slope osha defines a low slope roof as a roof having a slope of less than or equal to 4 inches of vertical rise for every 12 inches horizontal length 4.
Download manual of low slope roof systems book pdf epub mobi. Membrane roof system this manual provides best industry practices and technical information about the design, materials and installation techniques applicable to membrane roof systems used in low slope applications. How to install a low slope roofing system gaf liberty. Low slope roofing includes water impermeable, or weatherproof. Manual of lowslope roof systems fourth edition roofing. This fourvolume manual gives you comprehensive information about low and steep slope roof system design, materials and installation. The acheat master switches, located on the shifter panel, for each ac unit must be on. Nrca defines low slope roof systems as a category of roofing that includes weatherproof types of roof systems installed with slopes less than or equal to 3in12 14 degrees. Manual of lowslope roof systems fourth edition building enclosure. Ponding water is commonly observed at valley intersections for low slope roof and deck. These offer lasting protection against snow, ice and elements and hold up well to foot traffic on low slope roofs. Installing lowslope metal roofing metal construction news. For architects, roof designers, roof consultants, contractors, spec writers, attorneys, materials manufacturers anyone who needs authoritative, uptodate information on all aspects of roof technology the manual of low slope roof systems dominates the field.
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