What roof pitch is

Roof pitch, or slope, is a measure of how steep a roof is, describing the angle or incline of the roof surface. A steep roof rises sharply, while a low-slope or flat roof is nearly level. Pitch is typically expressed as a ratio describing how much the roof rises over a given horizontal distance.

Why roof pitch matters

Pitch affects how the roof sheds water, the roofing materials and systems appropriate for the roof, installation safety, and the roof's design.

Pitch and water shedding

• Steep-slope: Water runs off quickly.
• Low-slope/Flat: Water drains slowly, requiring specialized management.

Steep-slope versus low-slope roofs

Roof Type	Primary Materials
Steep-slope	Asphalt shingles, metal, tile
Low-slope	TPO, EPDM, PVC membranes

Why steep-slope roofs use shingles

Steep-slope roofs use materials like asphalt shingles, metal, and tile because these materials are designed to shed water by overlapping and directing it down the slope.

Why low-slope roofs use membrane systems

Low-slope roofs require a continuous, watertight membrane (like TPO, EPDM, or PVC) to manage water that does not drain rapidly.

Pitch and installation and safety

Steeper roofs are more challenging and hazardous to work on, requiring specific safety protocols compared to low-slope systems.

What about roofs with multiple pitches?

Many roofs have multiple pitches or a combination of planes. We address the entire configuration, including flashing at valleys and transitions.

Colorado Context: Roof Pitch & Slope

In Colorado, residential homes typically have steep-slope pitched roofs, while commercial buildings utilize low-slope systems, both engineered to handle local precipitation and snow loads.