Standing seam metal roofs and screw down systems are two of the most durable, energy-efficient, and low-maintenance roofing types. However, if you’re not quite an expert, choosing the best solution for you can be challenging.
As a rule of thumb, standing seam metal roofs are generally more resistant to water and elements. They also provide a higher visual appeal. However, screw down roofs are typically easier to install and more suitable for retrofitting. Screw down roofs are also more affordable.
The table below shows a quick comparison between standing seam and screw down metal roofs:
| Characteristics | Standing Seam Metal Roofing | Screw Down Metal Roofing |
|---|---|---|
| Design | Interlocking panels | Overlapping panels |
| Installation | Roof deck clips | Screws |
| Water resistance | Higher | Lower |
| Maintenance | Less maintenance | More maintenance |
| Retrofitting | More complex | Easier |
| Resistance | More resistant | Less resistant |
| Visual appeal | Higher | Lower |
| Cost | More expensive | Less expensive |
What Are Standing Seam Metal Roofs?
Standing seam metal roofs are made with long panels that run vertically from the ridge of the roof down to the eaves. These panels feature raised seams that interlock, creating a distinctive, clean, and modern appearance.
One of the most significant design features of standing seam roofs is their concealed fasteners. The panels are attached to the roof deck using clips, which are hidden beneath the panels. This ensures smooth and sleek aesthetics.
The design also allows for thermal expansion and contraction without causing stress on the roof structure or panels.
Pros
- High visual appeal
- Durable and resistant to elements and fire
- Low maintenance
- Good water resistance
- Energy efficiency
Cons
- More expensive than screw down roofs
- Installation complexity
- Noisier than other roofs
What Are Screw Down Metal Roofs?
Screw down metal roofs consist of metal panels that are fastened directly to the roof deck using exposed screws, typically fitted with neoprene or rubber washers to prevent water infiltration.
The panels can have various profiles, including corrugated, ribbed, or box-shaped designs, often featuring horizontal or diagonal ribbing patterns that provide structural support and contribute to the overall aesthetics of the roof.
On the downside, the screwed down design reduces thermal expansion and contraction, with an impact on the roof’s longevity. Water infiltration is also more common compared to standing seam roofs.
Pros
- Affordable
- Relatively easy to install
- Durable
- Design versatility
- Better for retrofitting
Cons
- Increased potential for leaks
- Exposed fasteners
- Higher maintenance needs
- Thermal stress can result in damage
8 Essential Differences Between Standing Seam Metal Roofs and Screw Down Roofs
Knowing the pros and cons of each roofing system is the first step to finding the right solution for you. The detailed comparison below can further confirm your choice.
1. Design
Standing seam and screw down roofs are both made of metal, but their similarities end here.
As explained, standing seam metal roofs feature long, continuous panels that run vertically from the ridge of the roof down to the eaves. The panels have raised seams (typically one to two inches in height) that interlock, creating the distinctive appearance.
The use of clips allows the panels to “float” over the roof deck, accommodating thermal expansion and contraction without causing stress on the roof structure or panels. This design reduces the risk of damage or deformation due to temperature fluctuations.
Screw down metal roofs, also known as exposed fastener systems, consist of metal panels that are fastened directly to the roof deck. Horizontal or diagonal ribbing patterns that provide structural support and contribute to the overall aesthetics of the roof.
In contrast to standing seam systems, screw down systems have exposed fasteners that somewhat reduce the aesthetic appeal of the roof.
Moreover, this design can result in additional stress on the panels and fasteners over time, potentially leading to issues such as leaks or deformation.
2. Installation
Installation differences can impact factors such as project timeline, cost, and required skill level, and screw down metal roofs have the upper hand in this aspect.
Installing a standing seam metal roof requires specialized tools and equipment, such as seamers, panel benders, and cutting tools. These tools are necessary for forming and manipulating the panels, as well as creating the interlocking seams.
Due to the more complex procedure, standing seam roofing installation requires experienced and skilled labor to ensure proper panel alignment and clip attachment. Installing such a roof is also a lengthier process, which drives costs up.
Screw-down metal roof installation typically requires standard roofing tools and equipment, such as drills, screw guns, and metal shears. The metal panels are attached directly to the roof deck using exposed fasteners.
This makes the installation process more accessible for contractors or even DIYers. Due to the simpler installation process and fewer specialized tools required, screw down metal roof installation is often quicker than standing seam installation. This can result in reduced labor costs and shorter project timelines.
3. Water Resistance
One of the most critical factors when choosing a roofing system is its ability to protect your home or building from water infiltration. The two metal systems achieve this with various degrees of success.
The hidden fasteners in standing seam roofing systems reduce the risk of water infiltration by eliminating leaks through the metal panels. The clips grip the seam and secure the panel to the roof without compromising the panel’s surface.
Moreover, the raised seams in these systems interlock, creating a tight barrier against water ingress. This design is particularly effective in preventing leaks on low-sloping roofs or in areas with heavy rainfall or snow.
If needed, standing seams can even accommodate sealants, such as butyl tape, between the seams and clips, further improving water resistance.
Screw down roofs don’t offer the same degree of protection, though. The exposed fasteners in screw down systems are more prone to leaks through the metal panels, increasing the potential for water infiltration, especially if the screws are not installed properly or if the washers degrade over time.
The overlapping panels of these roofs can create additional entry points for water. While proper installation and sealing can minimize this risk, there is still a higher chance of leakage compared to standing seam systems.
4. Maintenance
Maintenance is an essential aspect of any roofing system, but some options just need more maintenance than others.
Screw down metal roofs, with their corrugated surface and exposed fasteners, generally require more maintenance than standing seam systems. This includes periodic inspections and maintenance of fasteners, regular cleaning to remove debris, and potential repairs to address leaks or corrosion.
The hidden fasteners in standing seam roofing systems reduce the risk of corrosion and fastener degradation, as they are not exposed to the elements. This results in less maintenance required for fasteners over the life of the roof.
The long, continuous panels and concealed fasteners in standing seam systems result in fewer penetrations through the metal panels, minimizing potential points of weakness and reducing maintenance needs.
5. Retrofitting
Retrofitting an existing roof with a metal roofing system can provide various benefits, such as enhanced durability, energy efficiency, and aesthetics. Regardless of your purpose, screw down roofing could be your best option.
While standing seam metal roofs can be installed directly over existing shingles or other roofing materials without the need for a complete tear-off, the concealed fasteners and clip system may require the installation of an additional substructure.
Furring strips or grid systems create a suitable attachment surface for the standing seam panels and clips, but they increase installation complexity.
Like standing seam roofs, screw down metal roofs can also be installed directly over existing shingles or other roofing materials, eliminating the need for a tear-off in many cases. Their main advantage, though, is that these systems typically don’t require an additional substructure for attachment.
The panels are fastened directly to the existing roofing material, which results in faster installation and lower costs.
Both metal roofing types are compatible with a wide range of roof pitches, including low-sloped roofs, making them a versatile option for retrofitting various building types. However, the screw down systems are less suitable for low-sloping roofs where water resistance is crucial.
6. Durability
When selecting a metal roofing system, overall durability is another crucial consideration. In this case, standing seam metal roofs are your best bet.
These systems boast excellent wind resistance thanks to the interlocking design. The raised seams increase water resistance, while the floating installation reduces the stress of thermal expansion and contraction. All these factors minimize the risk of potential damage.
While screw down metal roofs offer adequate wind resistance, the exposed fasteners and panel overlaps can make them more vulnerable to wind uplift and damage compared to standing seam systems. The same factors also increase the risk of water leaks and infiltrations.
The corrugated profiles of screw down metal roofs can lead to the accumulation of debris, snow, and ice in the grooves, potentially causing damage or water pooling if not regularly cleaned. These roofs are also more prone to damage caused by thermal expansion and contraction.
7. Visual Appeal
The visual appeal of a roofing system can make or break the resale value of a property. Standing seam roofs have the upper hand in this aspect, too.
With their smooth, uninterrupted surface and raised seams, these roofs boast a sleek and modern appearance that complements contemporary architecture and design trends.
The hidden fasteners in standing seam roofing systems result in a clean, uncluttered look, as there are no visible screws or other hardware on the roof surface. Moreover, these roofs are available in a wide range of colors and finishes.
Screw down metal roofs often feature corrugated or ribbed profiles, giving them a more traditional or industrial appearance that can work well with certain architectural styles or in rural settings. The visible fasteners also add to the utilitarian allure, which can be less appealing to potential buyers.
However, like standing seam roofs, screw down roofs come in a variety of styles and finishes.
8. Cost
Lastly, cost is often a deciding factor when choosing a metal roofing system. Here, screw down systems win.
These roofs are typically cheaper due to the lower cost of simple, corrugated panels. Simple installation means that you won’t have to spend on additional components, such as clips. The installation costs are also cheaper, as these roofs don’t require lots of expertise to install.
Standing seam roof panels are more difficult to manufacture and harder to install. Hence, they are more expensive.
Conclusion
Standing seam and screw down metal roofs are two popular options for residential, commercial, and industrial buildings alike. Both are durable solutions, but standing seam metal roofs provide higher water resistance and are easier to maintain.
Screw down roofs, on the other hand, are cheaper and easier to install. They also offer good wind resistance and overall durability, but require more maintenance. Screw down systems are also more prone to leaks. With this in mind, you should evaluate your needs to find the best metal roof system for you.