Metal Roof Screw Pattern: Standing Seam vs. Corrugated Metal

6 minutes Read

Level Edge Construction

Metal roofing is one of the best-kept secrets in the roofing industry. But we don’t want it to be a secret anymore! Home and business owners across the country have been turning to metal roofing because of phenomenal benefits, such as:

• Lifespans of 40-70 years 🏡
• Fire resistant 🔥
• Low-maintenance ⚒️
• Affordability 💸
• Sleek aesthetics 💨

In order for metal roofs to provide the benefits listed above, they need to be installed correctly. In fact, there’s a specific metal roof screw pattern that must be followed to set the roof up for success and avoid leaks. Let’s break it all down— from different types of metal roofing, best practices, and spacing guides.

Different Types of Metal Roofing

We know that you’re likely picturing a metal roof as a rusty, loud tin roof on a barn and wondering how any homeowner could want one for their house. Well, we challenge you to take that image out of your brain because modern metal roofing is actually incredibly stylish and versatile. And, for what it’s worth, it isn’t any louder during rainstorms than any other kind of roof.

There are a few different styles of metal roofs:

• Corrugated Panels (Exposed Fastener): These panels have a more traditional metal roof look and are still used on agricultural structures and other commercial buildings. They’re characterized by frequent, thin ridges.
• Standing Seam Panels (Hidden Fastener): Standing seam panels are a more modern approach to the traditional look of metal roofs. These thicker panels with ridges are sleek and well-suited for residential and commercial properties alike.
• Metal Shingles: Metal roofing can actually be designed to mimic other popular roofing materials. You can find metal materials that look similar to asphalt shingles, slate, or clay tiles. These styles often fall under the “standing seam” category.

Screws or Nails: Which Is Preferred?

Roofing nails are used for asphalt shingle roof installations as well as some metal roof installations. However, screws are another option that most professionals prefer for metal.

When it comes to metal roofs specifically, screws offer the benefits of:

• Resistance to expansion and contraction: Metal roofs are known to expand and contract as temperatures fluctuate. Thermal movement can cause roofing nails to loosen over time, but the threads on screws resist movement.
• Strength and durability: Screws support the potential lifespan of metal roofs better than nails. They hold the materials in place for much longer than nails can. This is because nails are smooth and more likely to loosen and pull out.
• Prevent leaks: Since screws resist expansion and contraction and remain in place better than nails, they’re more effective at preventing roof leaks.

Metal Roof Screw Pattern & Spacing Guide

Since it’s clear that screws are the preferred choice for metal roof installations, let’s take a closer look at the best practices behind installing them. There’s a lot of technicality and math behind metal roof screw patterns, which is why it’s always best to leave metal roof installations to the pros.

Generally, you can follow this math formula to find out how many screws you need for your project. There are typically 80 screws in each roofing square. (A roofing square is equal to 100 square feet.)

• Take your roof square footage and multiply it by 80% (2,000 sq. ft. x 0.8 = 1,600 screws), or
• Multiply the total number of roofing squares by 80. (20 roofing squares x 80 screws = 1,600 screws)

Standing Seam Roof Screw Pattern

For standing seam roofs, the screws are installed directly into the top of the seam. The seam falls at the center of each 20 or 30-inch panel. Since the screws are hidden in this style of roof, it’s often considered to be more aesthetically pleasing for residential properties.

Many manufacturers require screws to be installed from bottom to top at a 45-degree angle from the shingle edge (if installing metal shingles.) Screws should be placed no more than 24 inches apart.

Corrugated Metal Panels Screw Pattern

Corrugated sheets have more frequent ridges and valleys than standing seam panels. Screws can be installed in the “high” or “low” parts of the sheets— AKA the ridges or the valleys.

It’s common to install screws in the “low,” and it’s standard to install screws after every third corrugation. Every fourth screw is reinforced with an additional screw on the “high,” immediately followed by another screw in the “low” that starts the next set of four.

Image Source: https://myrooff.com/how-many-screws-per-square-for-metal-roofing/

What Happens When You Don’t Use Enough Metal Roof Screws?

It’s important not to skimp out on metal roofing screws. The screw placement can quickly be the difference between a solid, long-lasting roof and one with frequent leaks.

If you don’t use enough roofing screws, you’ll end up with a weak roof that can loosen and be very susceptible to leaks. A metal roof with too few screws won’t stand up to inclement weather.

On the other hand, using too many screws also leaves the roof at risk of damage. While screws are more likely to resist expanding and contracting, extreme weather events can cause the material to warp if there are too many screws.

80 screws per square is the best formula for a secure connection.

Trust the Pros With Metal Roof Installation

You’ll be hard-pressed to find someone who recommends installing a metal roof by yourself without the proper experience. Not even every professional roofing company installs metal roofs, so that’s a clear indicator that they require highly specialized training and skill.

Level Edge Construction and Roofing is one of the few roofing companies in Minnesota that has the knowledge, expertise, and experience installing metal roofs. We’ll ensure that your screw pattern is exactly what it needs to be to keep your home protected and prevent leaks. And with our expert installation and regular maintenance, you can expect a roof that lasts twice as long as an asphalt shingle roof! If you’re interested in learning how we can install a metal roof for your home or business, reach out to Level Edge today.

FAQ

What is the spacing for screws on metal roofing?

Typically, screw spacing on metal roofing is around 12-24 inches apart.

Should you pre drill metal roofing?

Yes, it’s advisable to pre-drill holes in metal roofing to prevent damage and ensure a secure fit.

Do you screw metal roof on ridge or flat?

Secure metal roofing screws on the flat areas, not the ridge, for a watertight seal.

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Level Edge Construction