| You probably know that roofing slope is the | | | | A-frames, which look great!) Roofs that are too |
| amount of incline in a roof surface. It is usually | | | | low tend to make a home look boxy or |
| expressed as a ratio of "rise over run". For | | | | bottom-heavy. Many manufactured homes have |
| example, a 5:12 slope rises 5 vertical inches for | | | | this problem. |
| every 12 horizontal inches. It is easily determined | | | | 6. Quantity of Material Required. The steeper the |
| with a level and measuring tape. | | | | roof, the more framing, sheathing and roofing |
| What you may not know is that roofing slope is | | | | needed. For example a roof with a 12:12 slope |
| the most important (yet frequently ignored) | | | | uses 30% more material than a 5:12 slope. |
| factor in making a roof safe, functional and | | | | 7. Quantity of Labor Required. The steeper the |
| affordable. Here are ten factors to consider... | | | | roof, the more labor required. Not only is there |
| 1. Safety. Neither you, nor the workers you hire | | | | more material to be installed, but it is much slower |
| should have to risk life and limb to work on your | | | | working on a steep roofing slope. A 12:12 can |
| roof. The steeper the roof, the more hazardous it | | | | take twice as long per square to shingle as a 5:12. |
| is. | | | | A near-vertical mansard can take four times as |
| 2. Degree of Difficulty. Your roof should be | | | | long. |
| relatively simple to work on. I'm not saying it | | | | 8. Compatibility. Roofing systems are designed to |
| should be easy, but it shouldn't require scaffolding, | | | | function properly within a certain range of slope. |
| mechanical lifts or mountain-climbing equipment. | | | | Violating these requirements invites roof failure, |
| 3. Drainage. Your roof should not pond water as | | | | and can void your warranty. |
| dead-flat roofs do. Ponding causes leaks and | | | | 9. Special Requirements. Some systems require |
| premature roof failure. Building codes, warranties | | | | special considerations for marginal applications. |
| and good roofing practice all require positive | | | | Asphalt shingles for example, may require a |
| drainage. Tapered systems can correct slope | | | | two-ply underlayment on roofs less than 4:12. |
| deficiency, but they are labor-intensive and pricey. | | | | 10. Contractor Interest. The best roofers (which |
| 4. Do-it-Yourself Friendly. If you desire (or | | | | are the only kind you want) often have all the |
| finances dictate) that you do the roofing work | | | | work they can handle. They can afford to pass |
| yourself, your roof should accommodate you. | | | | on dangerous jobs. They don't want to risk |
| Roofing slope that is too low or too steep are | | | | injuries on steep roofs if they don't have to. If |
| both troublesome for the handyman. | | | | they bid a steep roof at all, you can expect high |
| 5. Curb-appeal. Roofs that are too steep tend to | | | | prices, because they probably don't really want |
| make a home look top-heavy. (Except for | | | | the job. |