| Materials commonly used in flat roof installation and | | | | modified bitumen product and finally a metal product. |
| repair: | | | | This roof is also less commonly installed owing to its |
| Built-Up Roof | | | | expensive nature, limited material warranty, etc. |
| Otherwise referred to as tar or tar and gravel roof, | | | | Single Ply Membrane |
| this roof comprises of 3-5 layers of asphalt laminated | | | | It is a myth that all single ply membranes are similar. |
| with coal hot tar, hot asphalt or pitch. Gravel is finally | | | | The single ply membranes include different |
| added for protection from UV rays. This is now | | | | membranes and their performance varies. The main |
| becoming less popular owing to its short life, abundant | | | | requirements of the single ply membrane nature that |
| heat gain, non-energy efficient, requirement of | | | | must be satisfied are being waterproof, non-flammable, |
| continuous maintenance and aesthetically unpleasant | | | | compliant with building codes, easy to work with as |
| nature. | | | | well as repair, pliable at different temperatures and |
| Modified Bitumen | | | | weldable. Most widely employed membranes are CPE, |
| This is just modified asphalt to enhance the plastic and | | | | EPDM, Hypalon, TPO, PVC, CPA, etc. |
| rubber-like properties. The commonly employed | | | | TPO has been used only for the past ten years and |
| modifiers include Atactic Polypropylene and Styrene | | | | hence its performance cannot be determined yet. |
| Butadiene Styrene. When this roof is properly installed, | | | | EPDM, otherwise called rubber, is a black single ply. |
| this can last up to around 15 years. | | | | Many EPDM installations have failed owing to improper |
| Metal Roof Installation | | | | installation, material failure and harsh climates. CPA and |
| Metal roofs are installed normally with underlying | | | | PVC are similar in properties and performance, the |
| asphalt saturated as well as coated roof. | | | | only difference existing in the chemical composition and |
| Underlayment is inadequate mostly in low slope roofs. | | | | viability of material. |
| It is better to apply an underlayment of asphalt, then | | | | |