Metal vs Shingles
Should you install a shingle or metal roof? Most people become interested in a metal roof for one of two reasons: one, they like the look and want that look reflected on their home. Second is they live in an area where extreme weather events are common and they believe that metal roofs hold up better during these events. In this article we will look at the differences in metal and shingle roofs and what considerations homeowners should take into account when selecting the right type of roofing material for their home.
Cost. The first consideration for metal vs. shingles is cost. A metal roof will cost a homeowner on average 3-4 times the cost of a shingle roof. There are multiple factors that affect the cost of a metal roof, but if you are going with a metal roof, using less expensive materials or installers is likely to cost you in the long run. So what makes metal roofing material so expensive? Let’s take a look at some contributing factors:
Every Order is Custom. A metal manufacturer will commonly manufacture accessories like ridge cap, drip edge and gable ends in mass at 10 LF lengths, however the actual panels that cover your roof surface have to be manufactured to the exact measurements of your roof. Because the panels are manufactured specifically for the measurements of your roof, every order a manufacturer gets is a custom order.
Local Manufacturers. Unlike shingles, Metal panels are made locally to your market. Metal is too expensive to ship and since every roof is a custom order you cannot mass produce the panels like shingle manufacturers do. Local manufacturers are smaller and as a result do not benefit from economies of scale.
Limited Competition. Since most metal manufacturers service their local region, which is often several states large, they do not have the national and international competition that shingle manufacturers have. This type of competition in the manufacturing industry would typically drive prices down, but due to the high barrier to entry into the industry and regional footprint, competitive factors do not really play a role in metal prices.
Performance. Standing Seam Metal Roofs and Architectural Shingle Roofs perform very well in fire, wind and hail tests. Standing Seam Roofs, when installed correctly, can withstand very high winds and can be resistant to smaller hail events. The warranty associated with Metal panels however, typically is only for the paint finish and not the panel itself. Because of this restrictive warranty you will not find a wind or hail warranty associated with metal panels.
Architectural Shingles do come with wind warranties. Shingle manufacturers such as GAF offer a No Wind Max Warranty on their HDZ line of shingles when installed using their high wind installation guidelines. Most other shingle manufacturers will offer at least a wind warranty up to 130 mph. While no asphalt shingle manufacturer will offer a hail warranty, all of the top shingle manufacturers have class 4 impact ratings. Shingles may not be as sexy as metal roofing systems, but they are tried and true and are backed by great warranties that are not yet available from metal manufacturers.
There are less expensive forms of metal roofing (Riblock Metal Panels) and shingle roofs (3-Tab Shingles) that perform well in moderate climates that do not experience significant weather events.
Skilled Labor. There is no other roofing material whose performance can be affected more by an improper installation than metal. An in-experienced installer can ruin a roof in a hurry with any roofing material, but with metal that risk is exasperated. Improper flashing installation is the most common point of failure.
One thing that can hurt you if you choose the wrong installer is the practice of installing metal panels over an existing shingle roof, commonly referred to as a layover. While most metal manufacturer’s installation guides allow for a layover, special consideration should be given to the following:
Decking. The condition of your roof deck should be inspected thoroughly before a decision to do a layover is made. Many defects such as delamination of the decking or moisture damage may not be visible until the existing roof is stripped to the decking. These concealed conditions can cause your roof deck to fail and cause costly repairs to your new metal roof down the road.
Fasteners. The fasteners your installer uses if they are installing over an existing roofing system need to be longer in order to fully penetrate the roof deck and secure the panels to the roof. A common work around for this is to install 1x1 boards across the roof, this is an acceptable solution, but in our experience may reduce the wind uplift rating.
Panel Profile. Layovers are most commonly performed when installing riblock panels. If you are installing a standing seam roof over an existing shingle roofing system you should choose a striated panel profile as a flat panel profile will show any imperfections in the roofing system you are installing over.
With Metal, custom fabrication onsite is inevitable, you should ensure you select a roofing contractor with the knowledge to perform these onsite fabrications. They need the proper tools and understand when it is appropriate to use a custom fabrication. There are far too many metal roofs out there ruined by installers just trying to make something fit. Bad fabrications lead to leaks and significantly reduce the life expectancy of the roofing system.
Conclusion. In summary, both metal and shingle roofings systems are great roofing materials. They each have their own advantages, but ultimately, finding the right contractor that can advise you on the right roofing system for your home and budget is key to a successful roofing project. Before engaging with a contractor do your homework on the wind ratings for your area, make a list of what is most important to you in your roofing system and prepare to ask for references and trade certifications.