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New Roof Installation Process

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  • Preparing for a new roof installation
  • Hiring a local roofing pro

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New Roof Installations

Whether you’ve hired a professional or plan to install a roof yourself, understanding the roof installation process and steps involved will help you ensure your new roof is properly installed. Here’s an overview of the roof installation steps for metal roofing and asphalt roof shingles.

It’s always smart to get roofing price quotes from at least four pre screened and licensed roof repair & installation professionals before starting your project in order to get the best price. Use our roof replacement costs calculator below to help you get an idea of your roofing installation cost and talk to local contractors.

If you know what to expect with your roof installation y0u can have a better understanding of what the process is. Heres a breakdown of what will happen when your roofing contractor comes to install or replace your roof.

1. Remove the Old Roofing

The old roofing will probably have to be removed before the new roofing material is put in place. Many people will install multiple layers of roofing over top one another to save time; but adding too many layers (i.e., asphalt shingles) can lead to premature failure in the roof. The old roof should be stopped down to the sheathing, and rebuilt.

2. Evaluate the Roof

After removing the old roof, evaluate the sheathing. Roof sheathing is made up of flat panels that provide structural support and a base on which roofing materials, like shingles, are attached. Look for any moist areas or trouble spots that will have to be replaced.

3. Protect Against Ice

If you live in an area that’s prone to ice for even part of the year, it’s important to install an ice and water barrier around your roof. This product goes on around the edges of the roof, but especially at the very bottom edge that is most prone to the buildup of ice. This sticky underlayment adheres to the roof sheathing, then nailed down for added strength and stability with roofing nails.

4. Put on the Drip Edge

The drip edge for the roofing goes down in two different parts of the roof installation. For the lower part of the roof it goes on before the underlayment, for the sides of the roof it goes on after. First, install the metal drip edge along the bottom edge of your home over top of the ice and water barrier. Nail it into place flat against the roof.

After you get the roof underlayment installed on your home you have to go over that with drip edge on the sides the same way that you did at the bottom. This prevents water from running over the edge of the siding and then back underneath it.

5. Roofing Underlayment Installation

Roof underlayment, whether felt paper or synthetic, is saturated in water resistant materials and comes in two thicknesses, 15# and 30#. The 30# underlayment is twice as durable as the 15#, but the synthetic products are much more durable than either felt paper option. If you are looking for the most effective way to protect your roof besides for the roofing itself, invest in the more expensive synthetic underlayment, it’s the most convenient and durable option.

Roll the underlayment along the edge of the roof and secure it in place using cap roof nails every four inches along the outside edges and around eight inches in the center. These cap nails should not go through the drip edge, but instead just above it.

Roll out one row of roofing underlayment after another securing it all down with roofing cap nails making sure to overlap the lower row by at least six inches with the next row. Overlap the underlayment sections up to the peak of the roof and then install a row straddling the peak so that the underlayment caps off both sides of the roof at the same time.

How to Install Metal Roofing

Start your metal roofing installation project by deciding which type of metal roof you want to have installed. You or your contractor will then start by installing a string line at the base of the roof peak at the level that you want your overhang. You put the string line in place to help keep your overhangs even around the edge of the roof. Most homes aren’t perfectly square and you will have to make minor adjustments to the roofing as you go to try to keep the overhang even. With the string line in place it will be easy to figure out how to adjust the piece.


Take care to get your first piece on the roof square so that either the side or the bottom edge is running square with the roof. You may not be able to get both sections of the roof square so pick the one that you care about the most and take your time getting it just right. Lay the roofing down so that the side with the taller ridge is facing to the right, this is the side that you want to lap over with the next piece. Now screw the panel down to your roof using screws with rubber washers to help keep water out. Put screws up one ridge at a time and spread them out into two-foot rows vertically. After you finish screwing one ridge move to the next and add the same number of screws in the same rows. Do this all along the panel until you get to the last ridge. Slip the next panel over top of the first covering the last ridge. Line the next panel up with the roof so it’s square and screw down into the overlapped ridge following that same screw pattern. Continue doing this along the entire roof until it is covered with the metal roofing.

Once you have all the roofing panels in place it is time to cap off the ridge of the roof. Start by installing a ridge vent and insulating under it with a waterproof sealant. Lock the ridge cap down over top of the vent and you’ve completed your roofing installation. Installing metal roofing panels or shingles on your own can be a hard and dangerous job to complete. We recommend finding a local roofing professional when looking for metal roof installation.

metal roofing installation

How to Install Asphalt Shingles

Asphalt shingles are known for being one of the simplest types of roofing materials to install. They are also the most common roofing types in the country for their price and curb appeal. The process of installing asphalt shingles is easier compared to other roof types which makes homeowners confident in taking up asphalt shingle installation as a home project. Go to our page for step by step guide to install asphalt shingle for your home roof.


Other: Sealing Roof Vents and Pipes

Throughout the installation of the roofing, there will be pipes and vents that need to be sealed. These are usually sealed with a special rubber boot that simply slips over the protrusion. In order to protect your roof and these vulnerable sections of the roof, protective rubber boots are slipped over top of the pipes and installed underneath the higher row of roofing when installing around shingles. When installing on metal roofing, you seal under the flashing using a roofing cement and then fasten the flashing right over top of the metal roofing using rubber washer roofing screws just as you did with the roofing itself.

Now that you know what goes into the roof installation process for a basic asphalt shingle or metal roof, you can decide if you want to do the work yourself or to pay a roof contractor to take care of it for you instead. Find local roofing contractors and get free roofing quotes with the form at the top of the page.