Denver CO Metal Roofing: Concealed Vs Exposed Roof Fasteners

Choosing between concealed vs exposed roof fasteners is sometimes the decisional pivot most Denver CO homeowners find difficult. Each one provides an excellent set of advantages and disadvantages they'll have to cope with.

However, as an extensively experienced and professional roofer in Denver CO you can rely on, we believe in knowledge. If you know each one's pros and cons, you can make the best decision for your roof in the fastest time possible.

We'll learn more about concealed vs exposed roof fasteners in this post.

First, let's introduce what these two types of metal roof fastener are. Concealed fasteners install your roof and secure it against your roof deck with clips that do not penetrate through the roof. Standing seam metal roofs commonly have this feature. In our experience, it has yielded excellent anti-leak capabilities.

On the other hand, Exposed fasteners are more affordable. They can secure standing seam metal roofs and prevent leakage with an oversized screw head. However, it does introduce an industrial look on most residential properties.

S-5 has an excellent and detailed description of each type of metal roof fasteners -- read more about it below.

Standing Seam vs Exposed Fastened Metal Roofs: 2019 Comparison

A metal roof is a metal roof, right? WRONG. Standing seam and exposed fastener roofs may both be metal and may even serve similar purposes, but the two styles are very different indeed.

Let’s start with the standing seam roof, or SSR as it is commonly abbreviated. The profile of this roof has flat panels intersected with evenly spaced vertical legs or seams. Fastenings are concealed on these panels – hence the reason the profile is commonly called “concealed fastener”. SSRs can be attached to roof decks via clips or with a fastening flange.

Fasteners are driven through clips into the roof deck but do not pierce the metal panels. The clip and the fasteners are then hidden within the standing seam. Thus, the panel is attached to the clips and locked together – either by snap-fit seam geometry or mechanically-folded during installation. SSRs come in a multitude of shapes and sizes, single-folded, double-folded, T-Shaped, Bulb-Shaped, and each either snap-together or are mechanically-seamed. The industry consensus favors standing seam, for its higher quality, ability to respond to “thermal cycling” and aesthetic design.

The Benefits of Standing Seam

While material and finish warranties are generally the same, most standing seam systems are offered with better warranties on the entire system. Some manufacturers also offer extended assurance that the roof won’t leak (weather-tightness warranty) over some given period of time. The absence of exposed fastening and concealed clip attachment lends itself to a much lower possibility of leakage as compared to the exposed fastener system which can require hundreds or even thousands of fasteners and rubber grommets that are subject to installation error and fatigue in service because they penetrate the weathering surface, and “pin” the panel to the structure.

Mount Away!

Of course, to toot our own horn, another way to preserve your SSR roof warranty is to utilize S-5!’s zero-penetration attachment solution technology. Our clamps can attach almost anything to your standing seam roof – all without piercing the metal and without violating the roof’s warranty. Rooftop mounting is a breeze when you do it The Right Way™.

Clean Lines

The most obvious difference between standing seam and exposed fastener is the lack of visible fasteners. Beyond the aesthetic benefits, exposed screws are a greater potential source of installation goofs. Under or over-tensioned screws, and stripped screws aggravate the obvious – which is that holes in the roof can leak if not properly executed. Direct attachment by screw fastening also does not provide for thermal relief when panels grow and shrink with hot and cold. Standing seam avoids these pitfalls with concealed fastening that also enables thermal response without fatiguing the attachment.

Maintenance-Free…Almost (Read More Here)

One major disadvantage of standing seam metal roofing is it is highly expensive than corrugated and exposed fastener variants. On the other hand, it has a huge amount of benefit for homeowners especially when it comes to aesthetics. Englert has an excellent account on concealed metal fastener's huge advantages for residences below.

Concealed Fastener Systems More Expensive but Proven to Last in Standing Seam Metal Roofing Systems

Over the past several months we’ve talked a lot about standing seam panels and their ability to resist all kinds of weather-related challenges as well as fire, hurricanes and salt air. We’ve compared galvalume to galvanized steel, polyester to PVDF coating and different metal and aluminum gauge thicknesses.

But the one thing we haven’t talked about are the two different types of metal roofing fastening systems—a very important topic that involves economics, aesthetics and maintenance.

Concealed metal roofing fastenerThe two most common ways of attaching a metal roof to a structure are exposed fasteners and concealed fasteners. Exposed fastened panels use a screw or nail to secure the metal roofing to the roof deck or purlins whereby the nail or screw actually penetrates an area where two panels overlap. This can involve hundreds and even thousands of fasteners which must be spaced and driven to maintain the integrity of rubber grommets which serve to prevent precipitation from gaining access through each hole.

Conversely, concealed clip fastened panels use a system where the fasteners are driven through the clips into the roof deck with no connection or piercing of the metal panels. The clip and fasteners are concealed beneath the standing seam panel material. The panel is then laid over and attached to the clips and then mechanically or hand locked to them.

Granted, exposed fastener metal roofing panels are a less expensive alternative to concealed fastener standing seam roofs. They work best in simple roofs like gables or shed roofs but get difficult to work with on structures with dormers, valleys and complex architectural features.While many people swear by them and have enjoyed years of service from them, exposed fastener roofs have lesser warranty times than concealed fastener systems. (Read Full Post Here)

True enough, it makes exposed fasteners something to avoid. We disagree -- both concealed vs exposed metal roof fasteners are excellent materials each with their strengths and weaknesses. In fact, you have a huge variety of screws to choose from that ensure zero leaks and guarantee exceptional aesthetics. Design and Build With Metal has an excellent blog post on why screws matter and which are your choices -- check it out below.

All Metal Building And Roofing Screws Are Not Equal, Simply Stated - Part 1

As important as knowing the differences in metal roofing products, it is more important to know the differences in the fasteners holding that roof in place. There seems to be a lack of knowledge about fasteners, not only among metal panel and metal building suppliers but also among the contracting community. It is extremely important to choose the proper fastener for the proper application so here are some things to consider…

Fasteners are described by their size based upon the major thread diameter, threads per inch, length, head style and type of drill point. It sounds complicated but broken down into its parts simplifies everything. The diameter is a numerical value used to describe thread diameter. A #12 diameter, the most common, has roughly 7/32” diameter threads. This is no different than visiting your local hardware store and choosing a screw that is a #6 or a #8. The higher the number, the larger the diameter.

The next item, threads per inch describes exactly that, how many threads are there in a one inch length of the screw. The threads per inch will vary based upon the material for which the screw is designed A screw designed for thinner material such as 26 gauge, will have less threads per inch than a screw designed for ¼” steel. The threads per inch will also dictate the pull-out strength.

The length is an easy one. It indicates the length of the fastener body, not including the head. Choosing the proper length is critical with the implementation of the new energy codes and the increased thicknesses and types of insulation. As an example, a screw with a length of 1-1/4” will not work well with 6” of fiberglass insulation.

The head style is indicated by several different descriptions; however, the vast majority of metal building fasteners are HWH or Hex Washer Head. This does not indicate that the fastener has a washer since there can HWH with a washer or HWH without a washer. It only indicates the type of head. Most HWH fasteners used in metal buildings are either a 5/16” or a 3/8” diameter head.

The last number indicates the type of drill point. Drill points are generally designated as #1, #2, #3, #4, #4.5 or #5. Don’t let this be confusing. The drill point denotes the metal thickness for which the fastener was designed. The majority of structural metal building fasteners are a #3 which means they were designed to drill through .036 or 20 gauge up to .210 or a little less than ¼” in thickness. A fastener with a drill point of #4, #4.5, or #5 is designed for heavier gauge steel and will be discussed below. (Read Full Post Here)

With an excellent understanding about metal roof fasteners, you can definitely make the best decision for your residential roof. We understand that you're researching metal roof fasteners because you're about to replace or install a brand new metal roof on your home. If you have yet to find an excellent roofer to help you, Roper Roofing is Denver CO's most experienced and exceptionally trained team of professional roofers who can help you. Contact us today!


795 McIntyre St. Suite 303
Golden, CO 80401

Phone: 720-809-7586



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