CONSUMER GUIDE TO ROOFING A guide for the selection of Roofing Services 9734—201 Street, Langley, BC V1M 3E8 604-882-9734 Website: www.rcabc.org Email: [email protected] Contents SECTION 1 CONSUMER GUIDE TO ROOFING ......................................................................................................2 SECTION 1.a CONSUMER TIPS ON BUYING A ROOF .................................................................................2 SECTION 1.b CHOOSING THE RIGHT MATERIAL FOR STEEP ROOFS.....................................................3 SECTION 1.c CHOOSING THE RIGHT MATERIAL FOR LOW SLOPE/FLAT ROOFS .................................5 SECTION 1.d REPAIR OPTIONS.....................................................................................................................5 SECTION 1.e SELECTING A CONTRACTOR .................................................................................................6 CONCLUSION ...................................................................................................................................................7 SECTION 2 SELECTING ROOFING PROFESSIONALS ..........................................................................................8 SECTION 2.a WHY CHOOSE A PROFESSIONAL ROOFING CONTRACTOR? ...........................................8 SECTION 2.b ROOFING CONTRACTORS ASSOCIATION OF BRITISH COLUMBIA ............................... 10 SECTION 3 ROOF GUARANTEES & WARRANTIES ............................................................................................ 12 SECTION 3.a RGC GUARANTEE PROGRAM DESCRIPTION ................................................................... 12 SECTION 3.b A REVIEW OF THE RCABC GUARANTEE CORP. (RGC) GUARANTEE CERTIFICATES, MAINTENANCE BONDS, AND CONTRACTORS’ GUARANTEES .............................. 15 SECTION 4 ROOF MATERIAL INSTALLATION .................................................................................................... 20 SECTION 4.a ASPHALT SHINGLES............................................................................................................. 20 SECTION 4.b CEDAR SHAKES AND SHINGLES ........................................................................................ 39 SECTION 4.c CONCRETE AND CLAY TILES .............................................................................................. 50 SECTION 4.d ARCHITECTURAL METAL ROOFING ................................................................................... 68 SECTION 4.e METAL ROOFING TILES ....................................................................................................... 94 SECTION 4.f BUILT-UP ROOFING (BUR/TAR & GRAVEL) ....................................................................... 94 SECTION 4.g MODIFIED BITUMINOUS MEMBRANES (TORCH ON) ...................................................... 100 SECTION 4.h MEMBRANE ROOFING NON-BITUMINOUS ...................................................................... 105 SECTION 5 ROOF MAINTENANCE ..................................................................................................................... 115 SECTION 5.a THE IMPORTANCE OF ROOF MAINTENANCE ................................................................. 115 SECTION 5.b CEDAR RESTORATION ...................................................................................................... 117 SECTION 5.c MOSS AND ALGAE CONTROL ........................................................................................... 118 SECTION 6 TECHNICAL INFORMATION ............................................................................................................ 120 SECTION 6.a ROOF DECKS ...................................................................................................................... 120 SECTION 6.b VAPOUR RETARDERS ........................................................................................................ 125 SECTION 6.c ROOF DECK INSULATION .................................................................................................. 128 SECTION 6.d VENTILATION ....................................................................................................................... 136 SECTION 6.e METHODS FOR GRANULE LOSS REPAIRS ..................................................................... 139 SECTION 6.f RIDGING AND WRINKLING OF MODIFIED BITUMEN ROOF MEMBRANES ................... 141 RCABC - CONSUMER GUIDE TO ROOFING SECTION 1 CONSUMER GUIDE TO ROOFING The information provided in this publication from the Roofing Contractors Association of British Columbia (RCABC) was compiled as a guide to assist consumers with the selection of roofing services in British Columbia. This roofing guide includes information sections reprinted from the RCABC Guarantee Corp. (RGC) Roofing Practices Manual (RPM) and other publications including those used by the RCABC Educational Foundation (REF) during the training of roofing apprentices and journey persons for the province of British Columbia. SECTION 1.a CONSUMER TIPS ON BUYING A ROOF PURPOSE This article is intended as an overview to assist in the process of buying a new roof. An overview of basic information is provided to help you make informed decisions with regard to roof types, materials, inspectors and contractors. It is not intended as a “how-to” roofing guide to enable the homeowner to act as a contractor or roofing inspector. TYPES OF ROOFS Aesthetics may be the most significant aspect determining the type of roof for your home. The roof is a large and often highly visible surface and can affect the overall look of the building. What you like has the greatest impact on your choice. Neighborhood covenants may also determine the type of roofing material. Slope The slope of the roof is another significant factor. There are limits of application for most materials depending on how steep your roof is. If a roof has a 5:12 slope, for every 12” of horizontal run, there is a vertical rise of 5”. On roofs with low slopes, like 3:12, some materials do not perform adequately to shed water, so they may not be recommended or may even be disallowed for that slope. Pitched (Water-Shedding) Low-Slope – Most materials designed for water-shedding roofs are designed for slopes above 4:12. There are fewer options when the roof slope approaches 2:12. Cedar is available down to 4:12 for shakes and 3:12 for shingles. Asphalt shingles can be applied as low as 2:12; however below 4:12 a superior underlay is required. Steep Pitch – It is difficult to safely walk on a roof when the slope is steeper than 7:12. Application is more difficult and therefore more complicated and expensive. There is a wide variety of material for steep roofs. 2 | Page RCABC - CONSUMER GUIDE TO ROOFING Flat (Waterproof) Flat roofs are not as common as pitched roofs in residential roofing. The methods and materials are similar to those used for commercial roofing. Proper application requires a contractor with special training and experience to apply commercial types of roofs. SECTION 1.b CHOOSING THE RIGHT MATERIAL FOR STEEP ROOFS One good way to determine the type of roof to buy is life cycle costing; comparing the cost of the roof with the life expectancy of the material, to calculate the annual cost. Roofing materials have a fire rating to determine their permissible application. According to the 2006 BC Building Code, high-occupancy buildings (noncombustible construction, i.e.: apartments, condos, public buildings) require Class A, B or C (Article 3.1.5.3) fire-resistance (the highest rating), residential single-family dwelling for most applications has no such requirement (Sentence 9.10.8.1.(1)). ASPHALT SHINGLES Asphalt shingles are the most popular choice in North America for water-shedding roofs. They are relatively inexpensive, easily applied and durable in all weather conditions. There are two basic types: organic and fiberglass. Both of these types are available in a variety of styles such as tab and laminate. Tab – Tab shingles are the kind most people recognize with their familiar tabs and slots. Although the three-tab style is most common, some manufacturers produce a five-tab shingle. They are very versatile since they can be used on a roof slope as low as 2:12 when special application methods are applied. Laminate – Laminate shingles (also known as architectural shingles). They do not have slots and tabs but rather have a strip adhered (laminated) onto the base shingle giving it a textured appearance. They come in a variety of patterns and colors. CEDAR Cedar comes in two basic forms: shingles and shakes. The basic differences are that shingles are sawn, shakes are generally split. Shingles are 3 ply and shakes are a 2 ply application. Cedar can be installed over solid sheathing, like plywood, but is better installed over spaced sheathing as it provides better drying. Shakes can be applied as low as 4:12, but shingles can go down to 3:12 with a reduced exposure. Grade – Cedar is graded to meet specific standards by designated cedar grading authorities. No. 2 Grade is the minimum accepted by the building code for shingles; however, some guarantees require No. 1 Grade to minimize warping, dishing and splitting as the wood ages. Shakes are required to be a minimum No.1 grade. Both must be a certified by a Standards Council of Canada accredited agency Treatments – Cedar is prone to decay since it is an organic material, particularly when it is close to overhanging trees and vegetation. There are, however, anti-fungal