How to Install Metal Roofing

Nowadays, sheet metal is an alternative to asphalt shingles, which are used on sloped roofs. While the tendency is to limit the use of corrugated steel to garden sheds, garages, and other storage-type structures, it would be foolish to dismiss this type of roofing for your home.

The next time you walk by a heritage building, take a few minutes to look at the roof. Metal roofing, a centuries-old technique, is far from forgotten. 

Preparing the Area for Sheet Metal Panels

Photo: ARBRE ÉVOLUTION

• Measure the roof, allow for overhang if you want the sheet to extend beyond the edge of the roof, and divide the width of the roof by three to determine the number of panels needed;

• Order your sheet metal panels with your roof measurements from a supplier;

• Remove old shingles and dispose of them in a rental waste container, and, while you are at it, rent an industrial-strength magnet to scoop up any nails that may fall off the roof;

• Fix the structure by replacing or repairing damaged fascias, as well as checking the structural soundness of the frame;

• Use a membrane to protect the roof from water infiltration, such as tar paper that can be nailed or tacked down or a self-adhesive membrane that is impossible to remove. Have a friend help you with the installation;

• Install furring strips by screwing them around pipes leading out of the roof, in the groove of valleys, along the edges and ridges, and on the rest of the roof;

• Install flashings along the edges and gables of the roof, then secure the flashing valleys with nails;

• Add a foam polyurethane membrane if necessary to guarantee a leak-proof seal.    

How to Install Metal Roofing

Metal roofing consists of corrugated sheet metal for roof structures secured with roofing screws. Roofing screws puncture the sheet metal and are embedded into the framework. The head of the screw has a rubber tip that prevents water from seeping in.

Installing the first sheet metal panel is tricky because, although it is only two feet wide, it is often very long. You have to measure the distance that needs to be covered at the top and bottom of the panel to make sure the last piece of sheet metal will be even. Once the first panel is installed, double-check the measurements and ensure everything is straight and even. Then, all that is left to do is install the remaining roofing panels, while ensuring that the bottom edge of the roof is even.

Photo: Don

After installing the metal roofing and trim, use a tube sealant to caulk the joints between the edge of the J-shaped profile and chimney and any other element that protrudes from the house's roof. Avoid using surface tar as it will soil the siding when it rains.

The corrugated shape of the panels provides ventilation between the frame and the various sections of the roof, thus preventing moisture build-up and mould growth. These panels are designed like such so that when installed, the panels overlap with the previous one while also forming a continuous seam that prevents any water seepage.

Note that interlocking metal panels exist.  

Why Choose Metal Roofing?

Metal roofing is entirely recyclable, 100% manufactured in Quebec, and lasts for over fifty years. Resistant to fire, strong winds, and bad weather, metal roofing does not oxidize, rot, warp, or crack and requires minimal maintenance. It is ultra-light and does not trap snow while also being extremely rigid.

The wide range of available profiles adds a design edge that is highly sought after by professionals, architects, as well as consumers. Although more expensive at the time of purchase, metal roofing remains the least expensive in the long run.

• Galvanized or painted steel sheet (between $14 to $27 per square foot).

• Aluminum sheet metal (between $9 to $14 per square foot).

• Copper sheet metal (between $24 and $36 per square foot).

• And, if your budget allows for it, stainless steel.

On the other hand, metal products do require quite a large amount of energy to produce. Thereby, the purchase price of metal roofing is significant. A scheduled inspection by an inspector is best to ensure that the metal expansion joints are airtight.

This roofing material may wrinkle or dent; install an anti-fall and braking system to control eventual snowfalls. (To learn more about this, read our article on roof snow guards.) Also, this material rattles when hit with rainfall or hail.

Note: A metal roof adds value to a house.

Is Sheet Metal an Antiquated Material?

Arguably the most iconic sheet metal roof is that of the Chateau Frontenac, which towers over Quebec City. According to Le Soleil, re-roofing the main tower of this famous architectural landmark, including the elements that adorn the cornices and dormers, took Toitures Falardeau two years to complete. The project consisted of covering nearly 30,000 square feet.  

With a wide range of colours, better durability than most, and no risk of moisture retention, our French-Canadian ancestors preferred sheet metal roofing many times over. Here are four types of metal roofing commonly found in Quebec:

• Galvanized steel is a white-ish/gray metal used for roofing panels. This material is easy to work with, aesthetically pleasing, sturdy, and watertight;

• Quebec-style sheet metal is malleable and moulded to accommodate sloped roofs. The panels overlap diagonally on the roof, which minimizes the risk of water infiltration;

• Batten-style sheet metal is bent and tacked onto a wooden batten. This type of roofing sheet is becoming increasingly popular with newer seamless installation techniques. These panels are deemed extremely sturdy;

• Clamped or standing seam metal sheet is best described as having a narrow, raised joint between the sheets. It is similar in style to batten-style sheet metal, but its installation is faster, and its seal is foolproof.

Note that sheet metal roofs, formerly used for houses and farms, are ideal for your chalet or shed. You can even trim the roof to fit a fan. For more information about metal roofing, which is part of our heritage, consult the Action Patrimoine fact sheet (French only).

Are you looking for metal roofing maintenance tips? Check out our article on the subject matter : Sheet Metal Roofing Maintenance Tips. 

Can Sheet Metal Withstand Northern Climates?

Steel and copper roofs require regular inspections to ensure that no cracks are forming and allowing water to seep into the structure. Climate change causes metal to expand and contract. As a result, freeze/thaw cycles and icy conditions wear down the material. Roofs with multiple dormers and flashing valleys are at greater risk. As ice falls from the roof, it can break through the sheet metal by repeatedly striking the dormer or the edge of the roof. Galvanized sheet metal roofs should be repainted every five to seven years. So, take the opportunity to inspect your roof, make any necessary repairs and install ice guards.

How to Replace Existing Roofing Material with Sheet Metal

According to EcoHome, it is possible to install metal roofing without having to remove the existing asphalt shingles, as long as it is not over multiple layers of said material. Should this be the case, remove the asphalt shingles to properly install the sheet metal.

Contractors will line the asphalt shingles and place the sheet metal over the battens. However, they will also ascertain whether any problems, such as water seepage, have damaged the structure or the insulation.  

Tools and Materials Required for Your Metal Roofing Installation Project

Average Price of a Metal Roof

Are you looking for more information on roofing? Check out our RenoQuotes.com Roof Renovation Guide. 

To learn more about average prices for various renovation projects, check out our 2022 Home Renovation Price Guide.