For most single-ply membrane roofing projects, chemical resistance of the membrane is not a consideration. However, in a few cases, the roof can be exposed to chemicals, oils, greases and the like. In these situations, the right membrane must be chosen. If chemical resistance is required, it must be balanced against other key factors that must be satisfied in order to meet all the requirements of the specific project. Other key factors may include protection against the damaging effects of UV rays and heat, ease of installation, heat seam-ability, guarantee or warranty requirements, etc.
In general, emissions and releases of chemical materials from industrial and commercial operations are tightly regulated and should never be a concern for a building's roof. In fact, membrane specifications often do not include requirements for chemical resistance and manufacturer guarantees and warranties typically exclude from coverage leaks or other damage caused by chemical exposure. However, membrane suppliers do occasionally get asked for guidance relating to potential chemical exposure. Building owners sometimes have concerns about such things as cleaning materials, oil, grease spills from grease traps, and "fumes."
Of course, designing a roof to meet the specific needs of a building remains the responsibility of the architect, specifier, engineer, or roofing contractor of record. Nevertheless, certain membranes can withstand exposure to chemicals better than others. In all cases, however, damage due to oil, greases, or chemicals are typically excluded from coverage under manufacturer guarantees and warranties.
TPO：“全方位”膜
房产申诉专员署屋顶膜有一个很好的平衡properties. They provide excellent protection against the damaging effects of UV rays and heat, good seam strength and easy welding, and high overall value. Guarantees or warranties lasting as long as 35 years can be obtained for adhered longer-life TPO membranes, such asEverGuard Extreme® TPO.However, TPO may weather faster than normal when exposed to certain chemicals. It may also absorb greases and oils, causing staining. Therefore, a second "sacrificial" layer of membrane should be applied in areas around grease traps, vents, and stacks that might be exposed to chemicals.
PVC：柔性膜
PVC屋顶膜比TPO更柔软，并且由于其易于处理，有时是首选。它比TPO更耐酸，通常推荐用于可能接触油脂和油的屋顶。然而，润滑脂和油通常会从板材中“抽出”塑化剂，导致薄膜硬化和脆化。
PVC-KEE: For improved resistance
PVC-KEE is widely regarded as having excellent chemical resistance. It can withstand a broad range of chemicals and solutions, making it a better choice than other heat-weldable single-ply membranes for projects that may experience chemical exposure. However, as noted in the next section, the degree of exposure, the area of exposure, and the frequency of exposure will increase the effect on the membrane.
项目特定耐化学性
Obviously, the degree of chemical attack on any material will be influenced by a number of factors and their interactions.
- 某些化学物质的组合可能比单个化学物质对膜的危害更大。
- Increasing the concentration of chemicals increases their damaging effect on the membrane.
- 较高的温度会增加化学物质对膜的破坏作用。
- 暴露程度、暴露面积和暴露频率可增加对膜的损伤作用。
结论
In general, roofs should not be exposed to chemicals. In fact, the first question that should be asked if a building owner has a concern about chemical exposure is how to eliminate or reduce the risk of chemical release from the building. If a roof is being exposed to chemicals, it might be a sign of broader, more serious issues.
但是，可能会发生油脂收集器泄漏、偶尔释放化学雾气等情况。任何类型的强酸、氧化剂和大多数强碱都会引起大多数屋顶膜的问题，无论是哪种类型。需要注意的是，任何材料的腐蚀程度都受到许多可变因素的影响，包括化学品浓度、温度、通风、暴露时间、流体稳定性、可能与该区域其他化合物发生的化学反应等。
建筑师、指定人、工程师或屋顶承包商应对建筑业主的问题进行评估，以确定项目特定条件是否与任何屋顶膜兼容。
