San Antonio Construction PVC Poly Vinyl Chloride Commercial Roofing
UNDERSTANDING LOW-SLOPE ROOFING SYSTEMS Very few people are experts on every kind of roofing system. However, the various types of low-slope roofing systems frequently considered for schools basically can be divided into two categories: multi-ply or single-ply. Multi-ply systems generally are bitumen-based (asphalt or coal tar), while single-ply includes polymer and metal systems. Several factors should be considered when selecting a roofing system. The installation design, its application and potential problems are important when determining the optimum system for a particular building. Another consideration is the environment. Although there are no nationwide programs to recycle roofing waste, some materials can be recycled or put to use in other ways.
PVC or THERMOPLASTIC Description: Thermoplastic sheets are seamed using hot air to heat-weld the two sides together. The resulting fusion of the sheets creates a seam as strong as the sheet itself. These sheets are manufactured from thermoplastic resins, the most common being PVC (polyvinyl chloride) and TPO (thermoplastic olefin). These sheets are typically reinforced with either a fiberglass or polyester scrim. Thermoplastic systems typically are mechanically attached to the deck through the lap area. This allows them to take advantage of their light color, scrim reinforcement and strong seams. Weldable systems also can be installed as a fully adhered or ballasted system.
Ideal Application: Thermoplastics are best suited for buildings where a highly reflective roof is desired, or the need for chemical resistance to animal fats is needed. They also are good for roofs where concerns about seams or puncture-resistance are an issue. For mechanically attached systems, it is necessary to have decks that will take and hold a fastener.
Potential Problems: These materials are very slippery when wet. On sloped roofs, walking can be dangerous if the roof is wet. The earlier versions of some of these products suffered premature failures that today's products overcome.
