Un système de toiture construite est un choix populaire pour les bâtiments avec des toits plats ou à faible pente. Often referred to by the acronym BUR, this system has been used for 100-plus years in the U.S.
What makes BUR systems so popular? Ils sont connus pour offrir une excellente protection grâce à leur nature redondante, car ils sont constitués de plusieurs couches de feuilles et d’asphalte. Ces couches sont ensuite recouvertes d’une feuille de finition ou d’une couche d’asphalte et de granulés. The multiple plies provide resistance to weather and heavy-duty protection for the building.
Components of a Built Up Roof System
Built up roof systems can be constructed in a variety of ways. Often, the built up roof system starts with a base sheet installed over the polyisocyanurate (polyiso) insulation or cover board, typically through the use of mechanical fasteners. The base sheet serves as the bottom layer of waterproofing protection for the roof system and provides a surface that will allow subsequent sheets to be adhered with hot asphalt.
A layer of asphalt is applied over the base sheet for the installation of reinforcing felt, sometimes called a ply sheet. Many people picture kettles of hot asphalt being mopped onto the base sheet in order to install the ply sheet, but advances in manufacturing have created alternative options. For instance, contractors can choose to use cold-applied adhesive solutions instead of hot mopping asphalt and kettles.
When saturated in asphalt or cold-applied adhesive, the reinforcing felt creates a barrier that provides additional resistance to water intrusion. Le processus est répété avec l’application d'asphalte ou d’adhésif appliqué à froid, suivi de la pose de couches supplémentaires jusqu’à ce que le nombre de couches souhaité soit atteint. The system is then either capped with a mineral-surfaced cap sheet or topped off by covering the top layer with asphalt and spreading gravel or slag.
This video provides an easy-to-understand look at the layers that make up a typical four-ply system.
Benefits of Built Up Roofing
Built up roofing owes its popularity to a number of benefits it provides, including:
- Time-tested technology. It's hard to argue with more than 100 years of history.
- Redundancy. Built up roofs provide many layers of protection, so if the top layer is damaged, the additional layers below will continue to protect the building from water intrusion.
- Guarantees/Warranties. Les systèmes BUR peuvent bénéficier de garanties allant jusqu’à 20 ans, en fonction des matériaux utilisés et du système installé. Check with the manufacturer for guarantee/warraaty requirements and coverage.
- Reflective cap sheets available. White-coated cap sheets are availableto help reflect the sun's rays away from the building, which can help lower internal termperatures.
There are many options when it comes to choosing an asphaltic roofing system, each with different benefits. Pour choisir votre système, le mieux est de commencer par déterminer les caractéristiques que vous souhaitez pour votre toiture. You can review this commercial product brochure to see a comparison of the different products, learn about their features, and browse available guarantees. Of course, you can always talk to GAF to help you find the best solution.
