What Is Pitch and Why Does It Matter?
Roof pitch refers to how steep, angled, or sloped your roof is. Residential roof pitches can vary greatly depending on the home’s architectural style. Most homes are moderately pitched; however, low and steep sloped roofs are also common. Your roof pitch matters for several reasons. Not only does it determine how your roof performs regarding things like drainage and protecting your home from bad weather, but it also dictates the materials you can use on your roof, the type of maintenance you need, and how repair and replacement work should be done.
How Is Roof Pitch Calculated?
The pitch of a roof is expressed as a ratio between height/vertical (numerator) and length/horizontal (denominator). For example, a roof pitch may be denoted as 4/12 or 4:12. This ratio refers to the number of inches of vertical rise for every 12 inches (or one foot) measured horizontally. When referencing roof pitch, the denominator is always 12, so any roof measurements taken must be converted to a denominator of 12. This allows for standardization in the industry.
Common roof pitches:
- 3/12 or less – low slope
- 3/12 – 9/12 – moderate pitch
- 10/12 or more – steep slope
Whether you’re trying to decide what type of roofing materials to buy or preparing for repair work, it is important that your roof pitch be calculated accurately. To determine the pitch of your roof, we recommend scheduling an appointment with one of the experienced roofers at Lyons Roofing.
How to Maintain Different Roof Pitches
As mentioned above, the slope of your roof will have some bearing on the materials used and the type of maintenance you will need. Similarly, different pitched roofs will have various weaknesses and their own repair issues to keep an eye out for. Below we review the materials used on different roof slopes and how you can keep them in good condition year-round.
Flat & Low-Slope Roofs
Though flat and low-slope roofs are more common in commercial settings, the rise in popularity of mid-century modern and contemporary architecture has resulted in an increased occurrence of flat roofs in residential neighborhoods. In addition to being incredibly stylish and beautiful, flat roofs offer excellent protection from the elements. However, they require special consideration regarding the materials you can use and how to keep them in good condition.
Styles of homes with flat or low-slope roofs:
- Mid-century modern
Flat roofing options include sprayed polyurethane foam (SPF), modified bitumen, and an elastomeric, aluminum, and glass emulsion. Because weight is a major concern with flat roofs, most flat roofing materials are designed to be incredibly durable while also being lightweight. A flat roofing system may also incorporate special coatings designed to minimize the damaging effects of the heat and sun and improve the roof’s energy efficiency.
If you have a flat roof, adequate drainage is incredibly important as the low pitch makes it more difficult for water to work its way off the roof. Consequently, flat roofs are more prone to leaks. However, you shouldn’t have anything to worry about with some care and attention.
Tips for maintaining a flat roof:
- Keep your roof free of debris
- Avoid walking on your roof
- Schedule annual roof inspections
- Take care of repair issues asap
Moderate Roof Pitch
Most homes in the US have moderate pitches. Moderate slope roofs are popular for many reasons, but perhaps their greatest selling point is that they combine exceptional functionality and longevity with pleasing aesthetics. With slopes ranging between 3/12 and 9/12, moderately pitched roofs have the greatest options regarding roofing materials.
Materials that can be used on a pitched roof:
- Asphalt shingles
- Architectural shingles
- Cedar shingles
- Cedar shakes
- Clay tiles
- Slate tiles
Moderately pitched roofs have many benefits, one of which is that a pitched roof allows water to drain effectively and quickly. They are also more energy efficient than flat roofs and are even well-suited to solar PV panel installation. Repair and installation work is also easier and safer than with steep pitch or high slope roofs.
Tips for maintaining a moderately sloped roof:
- Make sure all drainage is kept clear of blockages
- Replace any missing shingles or tiles asap
- Replace and repair damaged or rusted flashing
- Keep trees and overhanging branches pruned
- Keep pests from roosting or nesting on your roof
- Schedule annual maintenance inspections
To learn about some of the common problems associated with pitched roofs, review our blog.
Dealing with High or Unique Roof Pitches
At Lyons Roofing, we love dramatic roofs. Whether a steep gable or gently curved eyebrow windows that bring in some extra light, a unique or high-slope roof creates a lot of drama and visual interest. There are several styles of homes that have more unique roof pitches, including curved and rounded roofs or houses with a variety of roof pitches.
Styles of homes with steep roof pitches:
- A-frame homes
- Cape Cod
- Gabled homes
- Gothic revival
- Queen Anne
- Storybook cottages
The materials used on these more dramatically sloped roofs are asphalt shingles, wood shingles, and even clay, concrete, and slate tiles. Like flat roofs, one main concern with more unique and/or high slope roofs is leaking. With these roofs, a buildup of leaves and other debris is common. This can lead to pooling water that degrades your roofing materials and causes links.
When installing these roofs, it’s important that shingles or tiles are tightly fitted and professionally installed to ensure they are well-sealed. You must work with a licensed roofer like Lyons Roofer to ensure that all work is completed correctly and safely. We do not recommend attempting DIY roofing projects on high-pitch roofs.
Tips for maintaining steep slope or unique roofs:
- Schedule annual roof maintenance and inspections with a professional roofer
- Visually inspect your roof from the ground and speak with a professional roofer regarding any problems you see (such as broken or missing shingles)
- Make sure your roof drainage system is clear and clog-free
- Inspect the interior portion of your roof (attic and crawlspace) for signs of leaks, and call in a professional if you find anything.
No matter what pitch your roof has, Lyons Roofing can help you keep it beautiful for years to come. Schedule an inspection with us today by calling (520) 447-2522 or emailing us.