Metal shingles have the durability and low maintenance of metal panel roofs, but the charming look of asphalt or tile shingling. If you are replacing your old asphalt roof with metal shingles, you may want to know the basics of the roof replacement process.

1. Teardown

Although metal panel roofs are sometimes installed over the top of the old asphalt shingles, metal shingles are best installed over bare roof decking. Your installer will begin by tearing off the old roofing shingles and tar paper. Once this is done, they will inspect flashings around chimneys and vents and remove any that are damaged.

2. Decking Repairs

One benefit of a full teardown is that the plywood roof decking can be fully inspected. If punctures or minor holes are found, the decking board can be patched or replaced. Signs of moisture damage, such as rot or wet and swollen wood, means that the affected decking and possibly the insulation beneath must be completely replaced. Failure to repair or replace damaged decking will compromise the integrity of your new roof.

3. Trim and Flashing

Metal shingles require a starter trim along the drip edge of the roof, which is used to attach the first row of shingles. Your roofer will install weather shielding along the drip edge and then put in the starter trim on top of it. They will also install the first level of the flashing around any chimneys or vents that require new flashing. 

4. Shingle Installation

Shingles are installed from the drip edge upward to the roof peak. The first row of metal shingles clips into the starter trim. Then, your roofer uses a nail of the same metal as the shingle to secure the top edge. The next layer of metal shingles is installed staggered to the first. Each subsequent row clips into the shingle below it and then is nailed at the top edge. 

5. Sealing and Capping

Once the shingles are in place, the flashed areas can be sealed. A roofing sealant is usually used to seal around chimneys and square vents, but rubber boots may be installed around round vent stacks. Flashing and seals will also be installed along roof valleys or along hipped ridges. The finishing touch is the installation of the ridge cap on the main roof peak. 

Contact a residential roof replacement service if you are interested in a new metal shingle roof.