All roofs can be categorized into two groups based on their slope: steep and low. Due to its sleek, contemporary form and flexibility to accommodate patios, gardens, and other features, low slope roofs are becoming more and more common on residential buildings.
When choosing the right roofing materials or deciding what kind of structure to install, replace, or repair, it’s critical to comprehend the distinction between the two.
Steep Slope
Technically, any roof with a slope of 25% or above is considered to have a steep slope. They are made up of five fundamental parts:
- Roof coverings include the underlayment that sits beneath them to shield the sheathing from the elements, as well as shingles, tiles, slate, cedar shakes, or metal.
- Sheathing, which makes up the roofline, is the board or sheet material that is fastened directly to the roof rafters. In order for this material to maintain its structural integrity, it must be covered by an underlayment material and a roofing material (above).
- The rafters and trusses that are supporting the roof sheathing structurally are referred to as roof structure. This is the roofline’s framing, which is a component of the house’s framework.
- When there are joints, valleys, vents, or chimneys on a roof, flashing—typically sheet metal—is put there. They work to stop water seepage at these weak points.
- A crucial aspect of the entire roof design is drainage. It makes sure that rainwater is removed from the roof in a way that never jeopardizes the integrity of the building. Any roof structure’s layout, shape, and slope must take drainage into account.
Low Slope
A “low slope” roof is one that is essentially flat, but strictly speaking, it can be any roof that has a slope of between 0% and 24%. Although they have the same five fundamental components, the details vary slightly.
- Low slope roofs frequently use single-ply membrane roof coverings made of TPO, E.P.D.M., modified bitumen, or PVC. Additionally, “built up systems,” which are typically made of numerous layers of sheet materials and asphalt and coated with gravel, are frequently seen. Spray foam and metal are additional materials that can be used. Every material needs an underlayment to protect the roof sheathing from damage.
- Low slope roof sheathing might vary significantly from steep slope sheathing. There are some buildings made of simple wood boards, like a house, but there may also be structures made of metal, concrete, gypsum, tectum, and other fibrous materials.
- Although the rafters, trusses, and joists that support the sheathing of a low slope roof are fundamentally the same, the materials used here may vary and include steel, wood, or concrete.
- The goal of flashing is the same as that of installing on a steep slope: to stop water seepage at weak points.
- Since a low slope roof’s fundamental construction does not shed water as well as a steep slope roof does, drainage is essential. Gutter, internal drains, and downspouts can be useful for low slope roofs with any gradient. Special design considerations must be taken for truly flat roofs, and choices such stepped slope insulation might be a better idea.
Any roof may present difficulties. In addition to being more challenging to reach, steeper slopes with shingled roofs will eventually find it more difficult to defy gravity. As shingles on mansard roofs age, for instance, it’s not uncommon for nails to puncture the shingles. On the other hand, lower slopes that are “walkable” and shingled but still meet the requirements of the shingle manufacturer for shingle installation can present more difficulties due to wind-driven rain penetrating the shingles, debris accumulation, the need for additional protection barriers like ice and water shield, etc.
Any effective roofing solution, whether for a residential or commercial building, should strike a balance among all five of these factors. When meeting with clients and evaluating roofing needs, Andrews Roofing takes into consideration each of these factors equally. Although the roof covering may be most noticeable, we know that everything below it is equally important. Contact Andrews Roofing if you need help determining what kind of roof is best for your building or if you need a steep or low slope roof fixed. We would be pleased to come out and give you an estimate and a qualified advice because we have years of expertise in Hampton Roads in both commercial roofing and residential roofing construction.
