Contractor’s Guide: Exposed Fastener Metal Roof vs Standing Seam
by Delta Metals on May 08, 2023
If you're a contractor wondering which roofing material to use for your client's project, this guide breaks down the pros and cons of exposed fastener metal roofs and standing seam roofs. From ventilation to insulation, we cover the important factors to consider in your construction decisions.
Comparison of Standing Seam and Exposed Fasteners
The two most common ways of attaching metal roofing to your home are the standing seam or exposed fasteners.
What Is a Standing Seam Roof Panel?
A standing seam roofing system features panels of formed sheet metal with vertical ribs at the panel edges, installed by overlapping and interlocking adjacent panels' edges. The panels are attached to the substrate using concealed clips and fasteners.
The benefits of using a standing seam come from its energy efficiency, durability, and great look.
Advantages of Standing Seams
Standing seams have great maintenance durability and weathertight warranties. Since fasteners don’t penetrate the surface of the metal on a standing seam system, regular maintenance to check for withdrawing, loose, or damaged fasteners is even less frequent. Standing seams can expand and contract under thermal pressure preventing breakage. Opt for manufacturers with weathertight warranties that promise to reimburse if the metal roofing system leaks or fails during specific weather conditions.
Most importantly for the client, standing seams are incredibly energy efficient. Standing seam systems are frequently made with cool metal roofing materials that have highly reflective paint pigments in the coating. This means these systems do an excellent job of reflecting the sun’s rays and dispelling the associated radiant heat that other roofing types may retain, keeping your cooling cost low.
Standing seam panels have a great modern look that can be attached to nearly any building design. One of the most significant benefits of standing seam metal roofing is that no unsightly fasteners are visible on the surface, which means they aren’t exposed to UV, moisture, wind, and other elements that can cause a fastener to wear out over time. Also, standing seam systems don’t put holes in the panels that protect your structure. Plus, some people see fastener heads as unsightly, so using a standing seam system to hide them is common.
Disadvantages of Standing Seams
Seam metal fasters can be expensive compared to other metal roofing types, especially exposed fastener systems. After installation, if a panel or section has to be replaced due to damage, it can be difficult to separate the damaged panel from the rest of the structure. Additionally, that panel would have to be reapplied with sealant.
Standing seams are not suitable for flat structures. If your roof is at a 5/12 pitch, water will not adequately drain, which could lead to premature degradation, color changes, and the overall failure of the panel system. Furthermore, snap-lock systems should not be installed below a 3/12 pitch.
What Is An Exposed Fastener?
A less expensive alternative to standing seams is an exposed fastener. Exposed fastener metal roofing systems are easy to install; panels are fastened directly onto the roof deck with screws that penetrate the panels. Although metal roofing generally does not require maintenance, it must be inspected regularly to prevent any problems from developing further.
Advantages of Exposed Fasteners
One of the biggest advantages of exposed fastener panels is that they cost less than standing seam. The cost savings will be at least 50%, depending on the gauge and paint system.
An exposed fastener roof is an easier and faster installation than a standing seam because it requires fewer steps. Since the installation requires a simpler skillset, more contractors are qualified to install exposed fastening systems. Having more contractor options and less labor time means these systems are generally less expensive to install.
Disadvantages of Exposed Fastener Roofing
Since the fasteners are exposed on these panels, the fasteners need to be checked and possibly tightened during inspection to avoid leaks. Foam closures should also be checked at this time to make sure they are still in good condition. The roofs should also be checked for leaf buildup and cracked sealant.
Corrugated panels can require hundreds of fasteners to keep the roof in place. All of these penetrations in the roof leave a chance for moisture to get in. If the fasteners are not properly installed or become loose, the roof can be vulnerable to leaks.
Insulation and Ventilation of Metal Roofs
Decided on your roofing system? The second step to consider in metal roofing is proper insulation and ventilation.
What Type of Ventilation Is Best for Metal Roofs?
Like other roofing styles, most metal roofing relies on static ventilation, but installing ridge vents is a great idea. Static ventilation uses the natural effects of the rising hot air from outside the home to remove the heat build-up in your attic during warmer weather and the heat and moisture that collect during cold weather.
Ridge vents are the most popular option for metal roofs and effectively achieve proper attic ventilation. Ridge vents are installed at the roof's ridgeline and run continuously along the entire roof span. Ridge vent installation, done alone with metal roofing installation, is achieved by allowing a minimum of a 2” spacing between the panel ends that meet at the ridge.
What Type of Insulation Is Best for Metal Roofs?
Insulation to helps improve energy conservation and reduce noise pollution. I will discuss four main types: Fiberglass Batts, Rigid Board Insulation, and Spray Foam.
This insulation material uses fine, threadlike-glass formations woven together and mixed with other materials to form a thick insulating pad. It’s one of the cheapest and easiest ways to insulate a metal roof. It’s versatile, too, meaning you can cut it according to your needs. One of the few downsides comes from the danger of installation. The microscopic glass bits can damage your hands, eyes, and even lungs, so make sure you’re wearing protective gear.
Rigid Board Insulation
This material provides thermal resistance to foundations, roofs, and walls. It comes in sheets or panels of varying sizes, made from polystyrene or polyurethane. When the sheets are fitted together tightly and the joints caulked or sealed, this material offers maximum thermal resistance. UV rays from sunlight can damage it, so it must be installed appropriately.
This type of insulation is mixed with water and applied through high-pressure spray machinery as a heated liquid. When it reacts with the oxygen in the air and the water dries up, the polyurethane foam will expand, harden, and cure within minutes, which results in thick, rigid foam. It can be installed on old or new metal roofs without causing disruption or the need for re-roofing.
What Safety Precautions Should Be Taken When Installing Metal Roofs?
As a contractor, knowing the precautions to take when installing a metal roof is essential. When planning insulation, consider the building code, snow, and wind rating. Employees must be trained to perform all assigned tasks safely and be accountable for applying these skills. A competent person must conduct safety training and include information on recognizing hazards and what procedures to follow to minimize them. In this training, it is important to discuss tool safety features, safe operating procedures, and safe work practices, such as proper body placement and how to use personal protective equipment (PPE).
What Are The Maintenance Requirements Of Metal Roofs?
Metal roofs are extremely durable, but as with all roofs it's important to do routine maintenance. Depending on your metal roof application, you will have different maintenance needs. The roofs should be checked for leaf buildup and cracked sealant for exposed fastener metal roofs. Regarding standing seams, there needs to be regular maintenance to check for withdrawing, loose, or damaged fasteners. All in all, to prolong a metal roof’s life span, keep up with regular maintenance, like removing snow or debris, but rest easy because metal roofing is extremely durable and easy to take care of.
Metal Roofing Solutions
Whether you are a contractor or a house owner, metal roofing is a great choice for a long-lasting roofing solution. We hope you have the tools to make a confident and informed decision about what roofing, installation, and ventilation work best for your needs.
Before purchasing, consult a metal roofing expert to ensure you are up to date with the most cost-effective and efficient materials for your construction project. At Delta Metals, we have experts ready to help and answer questions, and we guarantee quality building materials at affordable prices.