You want to install a metal roof on your home but your home has a really low slope. You may be wondering if a metal roof is a good idea, or even possible, when working with such a low pitch.
At Western States Metal Roofing, we have been in the roofing industry for over 20 years manufacturing metal roof panels. Some of our products, such as standing seam, are often used on low slope roofs as they offer exceptional weathertightness. However, not every type of metal panel is the right fit for a low slope.
In this article, we discuss the appropriate metal panels you should consider when looking to install a metal roof on a low slope so you can decide on the right panel for your home.
Can You Put A Metal Roof On A Low Slope?
Just about any type of metal roofing panel will work with a 3:12 roof pitch or greater. However, when the pitch drops to a 2:12 or even a 1:12, you will have to use the right metal roofing panel profile. Low slope roofs are more susceptible to water damage because they do not offer much steepness for rainwater to runoff. If the water sits on the roof surface for too long, it can penetrate the roof, resulting in leaks and expensive repairs.
To avoid any potential damage, using the right metal panels that have maximum weathertightness is critical to having a successful metal roofing system on a low slope. It’s also critical to use an experienced installer on low sloped roofs as this type of metal roof will be more susceptible to leaking.
What Are The Best Metal Roof Panels For A Low Slope?
- Snap Lock Standing Seam
- Mechanically Lock Standing Seam
- 7.2 Panel
Snap Lock Standing Seam
Snap Lock standing seam, the most common type of standing seam, is a compatible metal panel for a low slope roof as it features a concealed fastening system.
By having hidden fasteners, it eliminates any screw penetrations on the surface where water could potentially seep through. Instead, the panels are installed by using standing seam clips and are snapped in place.
Snap lock is a secure system, but not as weathertight as mechanically seamed standing seam because it does not have the extra seaming. For this reason, snap lock will perform better in more mild climates where heavy snowfall or rain is not as prevalent. However, this makes snap lock easier to install as it requires less steps and labor.
Snap Lock standing seam panels are generally recommended for roof slopes that are a minimum of 2:12 to 3:12 depending upon the manufacturer's recommendations.
Snap Lock Standing Seam Specifications
Seam Heights: 1.5” and 1.75”
Panel Widths: 12”, 14”, 16”, 18” , Custom
Panel Lengths: Up to 52’. Lengths in excess of 52’ will have to be roll-formed on-site.
Mechanically seamed is a concealed fastener standing seam metal panel. The panel is designed to be used with clips that line up with one another so they can be locked together by a mechanical or hand seamer. The way the panels are fastened together makes it the most weather resistant standing seam roof and less likely to have any leaking issues.
This type of panel is perfect for a very low sloped roof as it has the greatest leak resistance from being seamed together very tightly with no entry points for water to enter through. It’s an excellent choice in climates that experience extreme weather conditions.
Mechanically fastened standing seam panels are generally recommended for roof slopes that are a minimum of .5:12 to 1:12 depending upon the manufacturer's recommendations.
Single vs. Double Lock Mechanically Seamed Standing Seam
Mechanically seamed panels can use one of two locking systems: single lock or double lock. Single lock has seams that are folded once (90 degrees) and double lock has seams that are folded twice (180 degrees). For maximum weathertightness, we recommend double lock as they are more common, more secure, and have an overall better performance compared to a single lock system.
In-Seam Sealant For Low Slope Metal Roofs
Roofs with low slopes (less than 2:12) require extra weather resistance. As a result, the single lock system and double lock system should always be used with any roof under 2:12 pitch up to .5:12 or greater with in-seam sealant. The sealant provides extra weather tightness which works well with low slope roofs where it is harder for water to runoff.
Seam Height For Standing Seam Panels
While WSMR carries standing seam panels with seam heights of 2”, you can find other panels on the market with heights of 1”, 1.5” or 2”. If you like the look of standing seam, we recommend a higher height as it makes the appearance of the seams more pronounced.
As you’ll see below, the higher the height, the lower your roof pitch will need to be.
- 2-inch double lock profile: Can be installed on a .5/12 pitch or greater with in-seam sealant.
- 1.5-inch double lock profile: Can be installed on a 1/12 pitch or greater with in-seam sealant.
A 7.2 panel, also known as a structural box rib, is well suited for a low slope roof. While the panel does feature exposed fasteners, it also has high ribs that results in extra weathertightness, strength and durability.
Each rib measures 1.5” high with 7.2” of spacing between ribs. The water has to rise to the level of the panel height to penetrate the panel seam and leak. On a low slope roof, when there’s heavy rain, it will not drain as quickly.
With such high ribs as those featured on a 7.2 panel, it makes it the most weathertight and low slope appropriate of all the exposed fastener metal panels.
7.2 Panels are generally recommended for roof slopes that are a minimum of 1:12 to 2:12 depending upon the manufacturer's recommendations.
7.2 Panel Compared To Standing Seam
Though it is not as weathertight as either of the standing seam panels, 7.2 panel is also the most affordable and easiest to install option of the three panel choices mentioned in this article.
The exposed fastening system of the 7.2 panel allows it to be simply screwed down directly onto the roof deck. This makes it the most DIY friendly low slope option mentioned in this article.
7.2 panel also has the largest variety of color options compared to standing seam as it comes in colors in both SMP and PVDF paint systems.
R Panel For Low Slope Roofs
R Panel is also well suited for a low slope roof. While the panel does feature exposed fasteners, it has strength and durability from its 1.23” high ribs that makes it compatible with a roof with a pitch of 1 in 12 or greater.
Choosing The Right Low Slope Option For Your Metal Roof
Choosing the right metal roofing material is important when you have a low slope roof to ensure your roof will enjoy the proper performance and longevity that metal roofing is known for.
Snap Lock Standing Seam may be the right fit if:
- You have a pitch of 3:12 or greater
- You are located in a more mild climate
- You are looking for an easier standing seam installation (as opposed to mechanically seamed)
Mechanically Seamed Standing Seam may be the right fit if:
- You have a pitch of 1:12 or greater
- You are looking for the most weathertight metal roof panel
- You are looking for the most secure panel
- Your roof is located in very cold, extreme climates
7.2 Panel may be the right fit if:
- You have a pitch of 1:12 or greater
- You are looking for an affordable low slope metal roof panel
- You are looking to do the installation yourself
- You are looking for the widest availability of color options
R Panel may be the right fit if:
- You have a pitch of 1:12 or greater
- You are looking for the most affordable low slope metal roof panel
- You are looking to do the installation yourself
- You are looking for the widest availability of color options
Standing seam is considered the premium choice in metal roofing not only for its performance and long lifespan, but also for its clean lines and enhanced curb appeal.
Learn more about standing seam metal roofing and the 3 types of standing seam panels that are available:
Discover more about 7.2 panel by reading: