How to Install Metal Roofing
If you are looking to upgrade your current roof, metal roofs can be an attractive upgrade to standard asphalt shingles. Not only will metal roofs conserve energy, but many types of metal can withstand the elements for many years. While the installation process can be completed as an advanced DIY project, it is complicated and may vary slightly depending on the brand of panel or shingle you select. We recommend that you complete this project with one or two helpers and fall protection gear designed for roofing jobs.
This guide will teach you about the types of metal roofing and give you step-by-step instructions on how to install a metal roof.
Don’t worry if you don’t have all the tools you need to complete this DIY project. Rent tools and trucks for any project.
1 – Consider Your Options
Things to consider before starting:
Whether you want to install a metal roof on a shed or a house, it is important to know the difference between the different types of metal roofs available. Let’s take a look at the most common types of metal house roofs.
Tin – An affordable and easier to install option than shingles, tin is the most commonly used type of metal roof. Often the material used is not tin, but galvanized steel or aluminum. Although it is durable, it will produce a little noise if there is rain or wind.
Copper – Often chosen for its aesthetics, the copper ceiling is also selected because it does not rust or require additional painting. Although they can be expensive and a bit more difficult to install, copper roof panels can withstand severe weather, fire, and are light enough not to put too much pressure on your home’s structure.
Aluminum – Lightweight and resistant to oxidation, aluminum is an excellent choice for coastal climates due to its resistance to corrosion from salt water. It is important to note that it must be painted and can easily dent.
Steel – Steel roofs can be expensive, but they are a lifetime investment. Noise is usually not a factor if you install a steel roof over asphalt. Galvanized steel, which is created by using a soft layer of zinc to protect the inner layers, is the most common type of steel roof.
Zinc – Durable, corrosion resistant, and recyclable, zinc is a softer metal and can be damaged by hail or extreme weather. Due to its higher cost and smooth surface, it would be a good choice for a temperate climate.
Corrugated Metal Roof Panels – While not previously considered the best metal roofs for homes, corrugated metal panels are gaining popularity due to their strength, energy efficiency, and corrosion resistance.
2 – Measure the Roof
- Use measurement tools to find the length and width of the roof from the outside floor.
- Calculate the slope of the roof by placing a carpenter’s level at the bottom of a beam in the attic. Measure the vertical distance (lift) from the 12-inch mark on the grade (run) to the bottom of the same beam.
- The slope is calculated as a climb over the race. For example, if the vertical height were 6 inches, its slope would be 6:12, 6/12, or 0.5, expressed as a decimal.
- Multiply the area by the slope. The result is the total square footage in your roofing project.
- Order roofing supplies by the square foot and add 10 percent more for waste.
- Be sure to order the roofing screws at the same time as the metal roofing panels to match the colors.
Tip: When installing a metal roof, you need to make sure you start from the right angle.
3 – Remove Old Roofing and Repair Any Damage
- Start from the top of the roof and remove the old shingles along with the flashing, subfloor, and vents.
- Hammer off large nails that are exposed when removed.
- Inspect the underlying roof sheathing for damage and make any necessary repairs.
- Install a layer of roof insulation as recommended by the roof manufacturer.
4 – Install Edging
- Use 1 1/4 inch nails to cover the outline of the roof with strips of metal eave flashing, also called trim.
- Place the corner pieces where the panels will meet the curves at the edge of the roof.
- If gutters are installed in the eaves, the eave flashing should be installed so that it protrudes from the edge of the gutter approximately 1/2 inch.
5 – Install Metal Panels or Shingles
- Align the first metal roofing panel so it overlaps the trim 1/2 to 3/4 inch and is square to the roof line.
- Make sure the larger edge is positioned so that the small edge of the next panel overlaps.
- Install roofing screws vertically along each panel rib. Position the first screw approximately 7 inches from the bottom and each subsequent screw 18-24 inches apart along the vertical travel.
- Secure the screws but do not overtighten them. The washer under the screw head should seal the panel surface without bulging or moving.
- Run a bead of 100 percent silicone sealant along the bottom of the short edge of the next panel. Install the panel so that the short lip overlaps the large lip. The silicone will spread and adhere, creating a seal.
- Screw the new panel into place as described.
- Continue adding panels until the roof is covered. You may need to cut the panels to fit the angles, using a circular saw with a metal saw blade.
Metal roofs are also available in tile form.
- Lay the starter row of metal shingles on the drip edge and secure it to the ceiling with metal roofing nails.
- Work from the starting row starting at the bottom corner in a diagonal pattern, staggering the shingles to avoid gaps.
- Most metal shingles will be attached to the roof using metal shingle clips, but the installation of metal roofing tiles can be system specific.
- Consult your shingle brand guide to determine the specific installation method required to preserve the warranty.
6 – Install Roof Ventilation
A roof vent installation kit will provide you with everything you need to ventilate your roof in one convenient package.
- When determining the location of the roof vents, measure the breather housing and mark the space on the roof. Leave room for the edge of the vent where it will rest on the roof.
- Outline the ceiling cuts that will be needed, then use a dexterity saw to cut out the outlined space. You should be able to see inside the attic when you’re done.
- Apply a coat of caulk to the edges of the hole, then snap the breather into position.
- Drill start holes if necessary, then slide down the vent with the fasteners in the installation kit.
- Apply a second coat of sealant around the edge of the outer vent. Then move to the attic and apply it to the bottom of the opening and vent.
- Place the cap over the vent opening and screw it into place.
7 – Install Flashing
- Flashing is a metal trim that sits over the joints where two sections of the roof meet. Helps direct water away from meeting points and keeps roof dry.
- Fold the flashing in a V shape to fit over the top ridge of the roof and the corners where the panels meet.
- The flashing should overlap the edge of the roof one inch to help direct the water.
8 – Safety Considerations
When learning how to install a metal roof, understanding safety is the most important step. Always make sure to prioritize safety when working on the ground.
Gloves and safety glasses should be part of your roofing supplies and should be worn at all times to avoid injury. Always prioritize safety when working on the ground.
- Make sure there are no electrical cables or low branches hanging from the ceiling.
- Secure your ladder at the base and at the point of contact with the ceiling. Test the ladder to make sure it does not move under your weight.
- Wear the proper fall protection equipment and make sure the system is properly anchored to the ceiling studs.
- Wear appropriate safety shoes when working on the roof.
While this overview can give you a good idea of what is generally required to install a metal roof, the process can be very complex and dangerous. A project of this scope is often best assigned to a professional installer. If you decide to hire professionals to install your metal roof, do your research and select a team that has experience in roof repair, the roofing system you want, and is insured (general liability and workers’ compensation insurance ) and licensed as required by your state.