Metal systems covers a wide variety of roofing systems and can mean many different styles and materials. Steel, stainless steel, aluminum, copper, and zinc alloys are all materials used for metal roofing. Each has different properties that affect durability, price, and appearance.
What types of metal roofs are out there?
Before making a decision on what type of metal roof you want, you need to know what types of are available. There are different types that impact price and performance that you should be aware of. It is important that this knowledge weighs in on your decision. You don’t want to make a decision to repair your existing metal roof, only to find out later that you have a metal roof that is a poor insulator and it would be worth your money to upgrade.
Conventional Metal Roofing Materials
By far, the most common materials used for metal roofs are steel and aluminum which can be used for a variety of different roofing systems.
Steel, used for most metal roofing, is heavier and sturdier than aluminum. Manufacturers have settled on a number of durable coatings and finishes that protect steel from rust and corrosion. Steel is usually zinc-coated for corrosion protection and then sealed. A coating of primer offers adhesion and a baked-on acrylic top coating adds colour and protection. Because sheet systems are designed for commercial applications, they generally are given highly durable paint finishes.
Aluminum, extremely lightweight, is used for some residential metal roofing. It won’t rust, but it must be painted or coated for appearance. Coatings are similar to those used on steel. Aluminum is a very soft metal, so it dents and mars easily and isn’t nearly as rigid as steel.
Aluminum-alloy coatings provide corrosion protection, but they react with alkaline chemicals in masonry mortar and cleaning solutions that might spill on the metal’s surface during construction.
Types of Metal Systems
Systems tend to fall into three distinct categories based on panel size and attachment method
Sheet metal tiles. Sheet metal shingles or tiles are stamped sheet metal with decorative finishes and textures. Commercially available tiles simulate clay tiles or cedar shingles, and they come in other decorative shapes.
Metal tiles are very light and can be susceptible to high winds. You should be aware of wind ratings for your neighbourhood. Metal tiles might not be right for your building. Metal tiles also are susceptible to crushing if technicians or others walk on the surface.
Sheet metal panels. These panels also are hydrokinetic roofing systems and are most applicable for roofs with a steep slope. Panels are available in a variety of profiles, sizes and thicknesses. Heavier-gage metal panels are suitable for applications such as warehouses and attach directly to the structural framing. The economic advantage of direct-attachment systems is the metal panels provide the structural diaphragm, roof sheathing, and waterproofing.
Different Types of Metal Roofs
We have covered roofing materials and systems, now we’ll look at the different styles you can create using metal.
R-Panel metal roofs are the low-maintenance metal roofing option. Their easy installation cuts own on labor, time, and disposal costs, so costs for the entire project are kept low. These roofs are also available in many different colours that look very nice on a roof. These roofing systems are very popular for both residential and commercial roofing systems. Their ease of installation has helped to make them a very popular flat metal roofing option. As with all metal roofing systems, these systems are prone to rusting and should be frequently painted or coated to combat this problem.
This is the classic metal roof, common on many older barns and shacks; the “original” metal roof. Corrugated metal panels are now often galvanized and used on restaurants and retail establishments to create a classic feel. Corrugated metal roofs integrate well with fiberglass skylight panels because they typically have similar patterns and structural designs. Corrugated metal roofs have been around for a long time and they have stood the test of time.
Architectural Standing Seam
This roofing system provides superior wind uplift protection and resistance to water than other metal roofing systems because of the way the panels interlock. They are extremely tightly constructed and provide a watertight seal that is superior to all other metal roofing systems. Many manufacturers apply a sealant to the panels in the factory, which works to maintain the structural integrity in thermal variations.
Modular Press panels are painted interlocking panels with standard dimensions and shapes and are growing in popularity for residential applications. They may be steel, aluminum, copper, zinc, or terne metal.
The roof panels are attached with hidden fasteners directly to the roof deck in most applications. They are usually 4-way interlocking to provide exceptional wind up-lift resistance.
High-End Metal Roofing Materials
Other forms of metal roofing are also available but can be very expensive. However, if you can afford them, they provide stunning roofs on luxury homes.
Copper metal roofing, rooted in centuries of use, will not rust, has no “finish” to scratch or peel, is soft enough to easily tool, and weathers naturally to a beautiful verdigris patina. Unfortunately, it’s extremely expensive.
Alloy roofing products are formulated for strength, graceful weathering, and durability. Cost depends on the specific material, but, as a group, they are pricey.
Stainless-steel roofing, a very expensive roofing material, won’t rust or corrode. Terne coating can give it a natural matte-gray finish
Lastly, we should look at how to maintain a metal roof so it lasts as long as the building. Roofers should walk directly over joists and purlins to prevent accidental bending or dishing of sheet metal roof panels. They also should minimize foot traffic on sheet metal roofs because scratches can expose the steel sheet, creating the potential for corrosion. Roofers and owners also should be careful not to scratch the surface when walking on or cleaning debris off a sheet metal roof. This will ensure you get the most out of your metal roof.
Metal roofing systems can be a cost-effective and viable choice for new and replacement roofing. Taking care in selection, design and installation will result in an attractive, low-maintenance solution.
Call us at Cambie Roofing if you think about installing a metal roof or need an estimate.