What kind of roof panel is right for your building? There are several elements to consider as you make your decision. What type of building is it? Where is it located? How big is the roof and what is the pitch?
These questions and more must be answered before delving into things like color and texture. The importance of proper roof design cannot be overstated, but the subject is also not that complex. Let's take a look at how to make your selection, the ways roofs are classified and which works best for your needs.
How to Choose Roof Panels
Style, scale and neighborhood aesthetics are key attributes of an attractive roof. With the variety of metal roof panels available, you should have no trouble finding just the right look for your building.
Style includes panel profiles, which run from corrugated to shake to standing seam and more. Metal roof panels are available to satisfy nearly any taste or need.
- Steel roof panels can be designed to appear like shake shingles, asphalt shingles or tile.
- They come in virtually any color, although a white “cool roof” can save the cost of energy year-round.
- Seams between panels can be flat and smooth or standing. Standing seam profiles not only impart a unique look, but these types of roofs are also excellent for channeling water.
Keep in mind that not every roof style complements every building style, nor is every style appropriate to each region. Areas of heavy snow require a sharply pitched roof to shed the snow while areas with little wind or rain can use flatter roofs.
Scale refers to the width of the metal panels.
- Broad panels on a small roof would look awkward while heavy-looking panels could overwhelm a modest building.
- Roofs with steep pitches go well with heavier shake-type panels while historical homes in Victorian or Cape Cod styles look better with a low profile, slate-like roof.
- Ranch-style homes and low-slope roofs look best with wood shingle-appearance or low profile seam.
- Standing seam is often used on log cabins, lower roofs and other rustic buildings.
Think of the roof panels as an accessory to match the rest of the house. Many steel building manufacturers have software programs that allow you to compare how different roof styles and scales appear in your design.
Unless you own a farmhouse in the middle of a hundred acres, you probably need to keep the rest of the neighborhood happy with your choice as well. In areas with homeowner associations and building associations, you may be limited to selections from the by-laws.
Structural vs. Architectural Roofs
You may hear the terms structural and architectural in reference to the roof. Each is a unique type of roof that serves a specific purpose.
- Structural roofs are made of sturdy panels that do not require a substrate or underlayment. They are installed over the purlins themselves.
- Structured roofs are of lower pitch and are relatively waterproof in standing water. They allow unhindered thermal movement without damage to the panels.
- Architectural roofs are made of thinner panels that must be installed on a substrate or other underlayment that supports the weight of the roof and keeps it watertight.
- Architectural roofs shed water quickly but tend to leak in standing water, and so are pitched higher.
Structural roofs are appropriate for large buildings, especially those with roof slopes of 2:12 or lower. The seams must be watertight. Architectural roofs are more typically seen in residential construction, where sharply pitched roofs are the norm.
Hydrostatic vs. Hydrokinetic
A hydrostatic roof is considered watertight and is often classified as a structural roof. It is used for low slope applications from 3:12 down to ¼:12. The seams are 1 ½ inches to 3 inches in height. Since it is a structural roof, it does not require an additional deck.
Hydrostatic roofs are capable of withstanding strong uplift pressures, and the tall seams impart strength and stiffness to span open framing members.
A hydrokinetic roof is considered “water-shedding” but not watertight. Typically considered an architectural roof, a hydrokinetic roof requires a steeper slope, at least 3:12 or higher. The seams are lower, from ½ inch to 1 ½ inches in height. As an architectural roof, it requires a separate deck or underlayment to support the roof panels.
Standing Seam vs. Concealed Fastener
A standing seam roof in one in which the edges of adjacent panels are bent upwards at a 90-degree angle, joined and folded one over the other to create a watertight seal. A sealant is applied to the pieces of metal as they are seamed together.
Standing seam roofs have the appearance of ribs running from the peak to the eave along the joints of the panels. Fasteners are usually clips that simplify installation and do not add weight to the roof. Standing seam roofs can be structural or architectural; the seam imparts added strength.
Concealed fastener panels are installed using a hidden clip or fastening flange plus fasteners. Concealed fastener roofs and walls eliminate the standing seam, providing a smoother surface. Many embossed panels use concealed fasteners to highlight the pressed design. The use of clips instead of through-fastening screws also allows free thermal movement during temperature changes without damage to the panels.
As you can see, a variety of roof types and panels are available to meet any design requirement. The panels come in any color or texture to create the appearance of traditional roofing materials while providing a strong, safe roof that is resistant to fire, hail and water.
Your choice begins with the type of building you require and the extent of the slope. Low slope roofs must be hydrostatic, available only as a structural roof while higher slopes can be either structural or architectural, as long as the roof is hydrokinetic and sheds water quickly.
All steel roof panels share the strength and durability of steel, and selecting white or lightly colored panels with specialized pigments can reflect and re-emit heat for an energy-saving roof option. With the proper, yet minimal maintenance, a steel roof will last for decades, so make a wise choice that you can live with.