| | | | | important parameters that cause aging and |
| | | | | fatigue to waterproofing membranes. This is not |
| We will check together | | | | the case for inverted roofs. |
| the pros and cons of inverted roofs. | | | | 4. The waterproofing layer plays also the roll of a |
| An inverted roof is one of the options for the | | | | vapor barrier: Two birds with one stone! |
| waterproofing and thermal insulation for a flat | | | | 5. The danger of water vapor trapped between |
| roof. | | | | vapor barrier and waterproofing layer doesn’t |
| The traditional or conventional way for | | | | apply to this case. The waterproofing layer is |
| waterproofing and insulating a flat roof is to place | | | | always in a temperature above dew point. |
| the waterproofing layer above the insulation | | | | 6. Flat roofs can be perfectly made to be fully |
| panels. | | | | accessible. |
| Long ago, before the advent of extruded | | | | 7. In case of a new floor addition most of the |
| polystyrene this was an one-way option. | | | | roofing materials can be reused. |
| Extruded polystyrene with its practically negligible | | | | 8. APP and SBS membranes could be applied |
| water absorption rate initiated the inverted roof | | | | semi-adhered. Fatigue and creep due to substrate |
| concept: insulation placed above waterproofing | | | | movements will be minimal. |
| layer. | | | | 9. This system is more suitable to be placed |
| We will briefly overview both the advantages and | | | | during adverse climatic conditions. |
| the disadvantages of this concept. | | | | DISADVANTAGES OF AN INVERTED ROOF |
| ADVANTAGES OF AN INVERTED ROOF | | | | 1. In case of a leak, repair procedures are more |
| 1. The waterproofing layer is perfectly protected | | | | difficult. |
| from mechanical abuse. Any of the usual | | | | 2. There is only one choice for insulation |
| waterproofing solutions for a flat roof is | | | | panels: extruded polystyrene. |
| acceptable. | | | | 3. Some quantities of water may be trapped |
| 2. The waterproofing layer is not exposed to UV | | | | between insulation and waterproofing layer. Slopes |
| radiation, other kinds of solar radiation and other | | | | should be created with utmost care. Allow for a |
| atmospheric factors of aging. It’s perfectly | | | | slope of at least 2%. Preventively increase |
| obvious and expected that its functional life will | | | | calculated insulation thickness by 10%. |
| be considerably longer. | | | | 4. Ballast weight may not be acceptable for |
| 3. Thermal shocks are among the most | | | | static reasons. |