Trim for your metal roof protects your roof and wall panels from moisture and the elements while adding visual interest to your building in the form of contrasting colors or interesting trim shapes.
Metal trim or flashing seals joints and directs water away from your building, protecting the entire structure. Wherever two roof panels meet, forming a valley or intersection, or at the edge line where the roof panels meet the endwall, there is a chance for moisture to enter the structure and damage the insulation and steel. Placing trim prevents water damage and extends the life of your building.
Continue reading for an overview of the type of trim available for metal roofs and information about their form, function and benefits.
Ridge Caps and Ridge Rolls
Ridge caps and ridge rolls are the different names for the same trim. You may also hear it called a peak sheet or die formed ridge. Peak sheets are available for corrugated rib type roofing only. The ridge cap is installed wherever two rising roof surfaces meet including the ridge, hip and top of a dormer.
A ridge cap is an attractive addition to the sloped roof of your metal building. It finishes the junction where the roof comes together at the apex of the slope. It protects against moisture infiltration. Ridge caps or rolls can be integrated with ridge vents for energy efficiency.
If you have a hip roof, a hip cap performs the same role as a ridge cap.
Gable Trim (Rake Trim)
Gable trim, also known as rake trim, is a finishing piece of metal flashing used along the edges of the roof line where the edge of the roof panel meets the endwall panels.
Rake trim is used anywhere a sloping edge ends such as the end of a dormer or gable. (A gable is a triangular section of wall panel running between the edges of a sloping roof.)
The joints where the roof panels meet the endwalls require the same protection against moisture as the roof ridge. Wind-driven rain, in particular, can enter these areas. Without the flashing, water can accumulate under the roof panels and eventually make its way into the interior of the building or home.
Moisture encourages mold growth and creates ceiling leaks. Both are expensive to repair, and some molds are toxic to your health.
Eave Trim and Gutter Trim
Eave trim is installed at the edge of the roof panels, creating a finished appearance. Eaves are the overhanging edges of the roof over the sidewall panels. The eave helps direct water away from the walls and windows.
Eave trim is also referred to as eave drip, redirecting rain run-off away from the fascia. It is installed at the lowest edge of the roof. If a gutter system is installed, it takes the place of eave trim and directs any run-off from the roof to the downspouts.
Downspouts are installed at various places along gutters to allow the rainwater to run to the ground and away from the foundation without encountering the wall panels.
Transition trim is wall-to-roof trim and creates a finished look at the juncture of the roof edge and adjacent taller wall panels. Commonly seen in residential structures where an attached garage wall joins with a higher wall of the main house or multi-story building, wall-to-roof transition trim protects the joints from water infiltration.
Anytime there is a change of direction or pitch, there is a need to seal the joint area to protect against moisture entry. Wall-to-roof transition trim is but one type of joint protection. It can also be found around chimneys and skylights.
As mentioned above, anytime two surfaces of different pitch come together, the resulting joint must be sealed against moisture. A valley is created when two parts of a roof meet at a downward angle.
Also, valleys are formed when gables or other changes of pitch occur. Since the roof valleys collect rain from the upper portions of the roof, they require additional protection to keep water out from under the roof panels.
Gutters may require an extra panel at the bottom of a valley to keep water from overflowing or splashing and running down the exterior walls. The higher the roof pitch, the faster the water will shed down the valley and into the gutter.
The Benefits of Steel Roofs and Trim
A steel roof is a long-lived roof that will last decades longer than other materials. A steel roof could well last up to 60 years or longer although most manufacturers’ warranties are a bit shorter than that.
- Steel is a durable material designed to withstand strong winds, flying debris, hail and chewing insects and rodents. A pitched steel roof sheds rain and snow quickly, relieving the potential for leaks or collapse.
- Steel is also fire-resistant. It is often listed as a Class A fire-rated non-combustible, the highest grade of fire-resistance possible. Because of its durability and non-combustible nature, a steel roof may reduce your insurance premiums.
- Maintaining a steel roof is a breeze. It requires minimal upkeep and repair. As long as the roof is inspected annually, cleaned of dirt, leaves, branches and other debris, the roof may outlast your building ownership. Concealed fastener steel roofs require the least amount of maintenance of any roof.
- Steel is environmentally friendly. It is 100% recyclable, so no scrap from construction or demolition reaches the landfill. Most steel contains a high percentage of recycled material, further reducing the need to mine ore with exhaust-spewing equipment. Steel mills have reduced their water usage to near zero, reclaiming, cleaning and returning any water used to its source.
- Finally, a steel roof is a good investment. The upfront cost may be more than other roofing materials, but the total cost of ownership is much lower due to the durability and minimal maintenance required.
Trim is available for any part of your steel roof. It does double-duty by sealing the roof panels against moisture and creating a finished appearance. Trim can be selected in the same color as the roof or wall panels, or you can choose complementary or contrasting colors to create visual interest.
When you design your steel building, remember the various types of trim you need and how you want your completed building to look.