On the outside, many standing seam metal roofing profiles look similar. You might think they look alike by merely looking at the different types of standing seam metal profiles. However, these profiles, including snap-lock, nail strip, and mechanical seam, are noticeably different.
They differ in functionality, setup, attachment method, and even price. These profiles have more differences, which we will address in this article. We will also discuss each profile’s uses, pros, and cons to determine which is most suitable for your roofing project.
What Is a Mechanical Seam Standing Seam Roofing Profile?
The panel edges of mechanically seamed metal roofs have vertical legs that line up. Experts seam them together using an electric or hand seamer. The clip moves over the male leg that faces downward and is then fastened down. The female leg, on the other hand, is positioned over the clip to hide it. An electric seamer is a better choice for seaming these components because it gives a tighter seam than a manual one.
Mechanical seam profiles usually need expansion clips for thermal movement. Two types of this profile are double or single locks, which people use on standing seam metal roofs.
A single lock seam has just one seam fold (90-degree seam). This type of lock is not labor-intensive and isn’t stressful to install. When it experiences damage, replacing it is much easier than replacing a double lock. Those are some of the pluses of using a single lock seam.
On the other hand, a double lock seam has two folds, meaning that they fold it twice. It is ideal for buildings that need to be very leakproof. However, it is not easy to install or replace, as it requires more labor.
Pros and Cons of Using Mechanical Lock Profiles
Pros
- Different seam heights: Because the mechanical lock profile is mechanically seamed in the field, its seam heights vary, usually 2″, 1.5′, and 1″.
- Ideal for roofs with lower slopes: You can use it for buildings with roofs that have lower slopes (2/12 and below). The exception is when the design limitations or specifications state otherwise. However, when using a mechanically locked profile with a pitch less than 2/12, you may need a seam sealant. Hence, you should seek guidance from your manufacturer for the lowest pitch they recommend.
- Highly waterproof: Low slope roofs have the potential for having water pool up on the roof, therefore causing roof damage over time. Using this mechanical lock profile will reduce the chances of a leak happening because it has panels that are seamed together, making it waterproof. Using a sealant even makes it more waterproof.
- Different locking choices: This profile type offers two locking choices: double and single. The double-lock profile happens to be the more popular choice. However, to decide on the most suitable lock for your project, you need the guidance of an expert.
- Long-lasting and solid profile: The panels are mechanically seamed tightly to give the structure more rigidity. The tightness makes it more resistant to high winds and more durable.
Cons
- Labor intensive: Many installers seam these profiles together with a robotic seamer instead of a hand one because using them is easier, and the result is usually neater. One would think using robotic seamers would make the process tedious, but that isn’t the case with this type of profile. Regardless of what tool you use, the process is still time-consuming and requires more work.
- Costs more money: Because the seaming process for mechanically seamed profiles requires more labor and time, they are the most expensive standing seam roof option. The cost of installation varies with the roof’s complexity, accessories, and many other factors.
- Increased chance of having issues during seaming or unseaming panels: This profile could be a problem if the seamer jumps and causes damage to the seam. When this happens due to adjustment errors or misuse, it can seriously damage the panel. Other potential problems include cracking the material during unseaming or seaming panel legs and “telegraphing,” among others.
What Is a Nail Strip Standing Seam Roofing Profile?
A nail strip (fastener flange or nail flange) is a standing seam metal roof with flat panels and elevated ribs that give the roof long, tidy lines. It fastens to panels with its male leg or the space between its notches. The other leg (female) moves over the male one and snaps to conceal the fastener head.
Similar to a snap-lock profile, the nail strip attaches directly to the roof deck via the male leg. Using a nail strip eliminates the need for retainer clips.
Pros and Cons of Nail Strip Profiles
Pros
- Easy installation process: Installing nail strip profiles is a straightforward process that doesn’t require many tools. The process is not time- and money-consuming; hence, it is a popular choice for homeowners who like DIYs. The easy process of installation also makes it an ideal choice for projects with tight deadlines.
- It is economical: Although standing seam metals are on the higher side of cost, nail strips are the least expensive type of standing seam metal panels. They are the most affordable because installing them is simple, not labor-intensive, and they do not need extra accessories like clips.
- Excellent for residential projects: Nail strips are the cheapest standing seam panel option. This quality makes them in high demand for residential projects.
Cons
- The roof’s functionality is exclusively dependent on the fastener head: The fastener head is the sole thing holding the roof to the structure in a nail flange system. So, when exposed to a specific pressure, the wind can rip the metal off the fastener head and slacken or separate it from the roof.
- Can’t withstand inclement weather: A nail strip profile can’t withstand extreme weather conditions due to functionality limitations and restricted access to engineering. Hence, it is not ideal for buildings in areas prone to adverse weather conditions.
- Limited length of panels: Many nail strip profiles have a limited panel length of 25 feet as a result of thermal movement problems and pinning.
- Not ideal for roofs with low slopes: If you have a roof below 3/12 pitch and install a fastener flange, water may become stagnant in the panels, and leaks may occur, causing damage to the roofing system or the building. This is because of the slow-motion hydrostatic condition of the roof.
What Is a Snap-lock Panel Profile?
A snap-lock panel profile is a standing seam metal panel that is roll-formed using a portable or in-plant roll-former. It is roll-formed into shape with a female and male leg that snap together and doesn’t make use of a seamer to join the panel legs.
This profile is popular for its use on residential and commercial buildings. People typically use snap-lock profiles on roofs with slopes of 3:12 or more. They use clips or fasteners to fasten the metal panel to the roof deck. However, the seams are firmly snapped into position. Because of the required bends to secure the snaps and the complex nature of the panel legs, it takes more material to form snap-lock profiles using a compact roll-former.
Pros and Cons of Using Snap-lock Profiles
Pros
- The seaming process doesn’t require a seaming tool: The installation of this profile eliminates the need for a seamer by allowing the installer to snap the male and female legs together.
- Usable for different applications: Snap-lock profiles are versatile. You can use them for commercial, architectural, and residential projects. It’s almost “one profile fits all.” This is very beneficial to panel manufacturers or contractors because they can offer and apply one profile for different projects.
- Faster and easier to install: Installing a snap-lock profile is easier and faster because you don’t need to seam them mechanically. As a result, the process is not labor-intensive and is cheaper.
- May come with commercial weathertight warranties: Some snap-lock profiles may qualify for the weathertight warranties that most manufacturers offer if they make their list of approved profiles. If the slope, environment, and other conditions of the roof are fit for a snap-lock profile, then you can use one.
Cons
- Must be firmly snapped into position: Snapping the panel seams into place tightly is crucial. Failure to do so will cause them to come apart over time and become weakly resistant to leaks.
- Limited to steep slope roofs: You can only install snap-lock profiles on roofs with a 3/12 pitch and more. It is not suitable for a roof with a lower pitch. You can only use this profile on steep slopes because the manufacturers designed them to get rid of water. However, applying sealants to the snap-lock panels’ legs can aid their water resistance.
Conclusion
All three profiles discussed in this article are suitable for constructing a long-lasting, solid, and attractive standing seam metal roof. Mechanical seam, snap-lock, and nail strip profiles are not the only standing seam metal roofing types. However, they are the most popular options. The kind of project you are working on and other factors will determine which of the profiles you’ll opt for.
Now that you’ve gone through the description, advantages, and disadvantages of each profile, deciding on the best fit for your project should be easy. We also advise that you consult the manufacturers for their suggestions.
