Why understanding the process matters
Putting on a new roof is one of the most significant home improvements a homeowner can undertake. Decisions made before the first shingle goes down affect everything from curb appeal to energy efficiency and long term durability. Even if you plan to hire a contractor, knowing the roof installation process gives you better questions to ask, clearer expectations about timing, and confidence that each step has been completed correctly.
As a local team at Mountain View Roofing, we build this guide to help you understand the entire journey from inspection and permitting to cleanup and warranty.
What “putting on a new roof” includes
Most homeowners use several phrases to describe the same job: New roof installation. Roof replacement. Reshingling a roof. Reroofing a home. In practice, they describe a sequence of tasks that begins with removing old materials, inspecting and preparing the roof deck, installing moisture barriers, flashing, and ventilation, then laying the new shingles or tiles and finishing with ridge caps, cleanup, and a final inspection.
Industry leaders outline a similar sequence because it reflects how a sound roof system is built layer by layer. The choice of roofing material significantly impacts the appearance, durability, and cost of your new roof.
Common residential systems you will encounter
- Asphalt shingles remain the most common choice for residential roof installation. Some asphalt shingles are designed to imitate wood shakes, providing a traditional look.
- Architectural shingles are a popular upgrade, offering a dimensional, three-dimensional appearance and enhanced durability compared to basic options.
- Concrete or clay tile is heavy yet long lasting and popular in many coastal and Mediterranean style neighborhoods.
- Metal roofing offers longevity and excellent wind performance when installed correctly.
Each material has its own installation details and manufacturer instructions that must be followed to protect warranties.
Preparing for your roof installation
Inspect and assess the current roof
Start with a careful inspection of the existing roof covering and the structure beneath it. Be sure to check for loose shingles that may need securing, as these can compromise the roof’s integrity. Inspect for old shingles that may need to be removed or replaced to ensure a solid foundation for any new materials.
Look for brittle or curling shingles, missing tabs, soft spots in the decking, water stains in the attic, rusted flashing, and evidence of ventilation problems such as mold or excessive heat. A pro will check the attic as well as the exterior to size the project accurately, then provide a written scope, materials list, and timeline. Reputable manufacturers recommend this preplanning and point out that permits may be required before work begins.
Choose the right roofing materials
Your climate, roof pitch, budget, and architectural style guide this choice. Architectural asphalt shingles are a common upgrade over three tab shingles because they add dimension and wind resistance. Tile and metal systems can deliver distinctive looks and longer service life when supported by proper structure and detailing. Ask about color blends, reflective options, and manufacturer backed warranties.
Place equal weight on the underlayment, flashing, and ventilation, since those hidden components protect the roof system. Special shingles are required for certain areas such as the ridge to ensure proper protection and airflow.
Plan, permit, and stage the site
A roof replacement is a coordinated project. Materials are delivered just before installation. A dumpster or dump trailer is placed for tear off debris. Walkways, plants, and siding are protected. You arrange driveway access and move vehicles to the street on installation day. These standard practices keep the job organized and protect your property.
Requesting a free estimate for your roofing project
Requesting a free estimate is a crucial first step in any roof replacement project. Start by reaching out to at least three local roofing contractors to compare not just prices, but also the scope of services and the quality of roofing materials they offer.
A detailed estimate should break down all costs, including labor, disposal of old roofing, and the specific types of shingles or other materials being used, such as architectural asphalt shingles or specialty products. Don’t hesitate to ask each roofing company about their experience with roof installation, roof repair, and re-roofing projects similar to yours.
A reputable contractor will walk you through the roof replacement process, answer your questions, and provide a transparent, itemized quote. This approach ensures you understand exactly what’s included in your roofing project and helps you make an informed decision for your home.
Roofing step by step: the full installation process
The details below map to a typical asphalt shingle roof. The same principles apply to tile and metal with product specific variations.
Step 1. Tear off the old roof and protect the home
Crews remove existing shingles, underlayment, flashing, and nails in sections. A roofing shovel and pry bar are commonly used to lift old shingles and pull out nails during the tear off process. Property protection comes first. Crews place tarps and plywood to shield landscaping and windows, set clear dump zones, and keep vehicles on paved surfaces.
Responsible contractors also clean out gutters as each section is removed. A professional magnet sweep happens at the end to capture stray nails and remove other debris to ensure safety and cleanliness.
DIY note: This part of the work is physically demanding and can be hazardous. Roofing contractors account for a significant share of fatal falls in construction each year, so fall protection and ladder safety are non negotiable. Consider this risk carefully before choosing a DIY roof replacement.
Step 2. Inspect and repair the roof deck
With the surface removed, the decking is exposed. Plywood sheathing is commonly used as the decking material and should be carefully inspected for any damage. Replace any rotten, broken, or delaminated sheathing.
Gaps in plank decking beyond manufacturer limits must be corrected to ensure fasteners hold and shingles lay flat. Good contractors document any decking replacements before moving forward.
Step 3. Install drip edge, underlayment, and leak barriers
At eaves and rakes, drip edge directs water away from fascia and into gutters. After preparing the roof decking, installing underlayment is a crucial step to provide a continuous secondary water barrier.
Crews roll out the underlayment from the bottom up, ensuring proper overlap for extra protection against water penetration and to prevent leaks. In water prone areas such as valleys, eaves, and around chimneys, an ice and water shield (or water shield) is installed to prevent water infiltration and ice dam damage. Valley flashing is then installed in roof valleys, cut to size, overlapped properly, and sealed with roofing cement and nails to prevent leaks.
In some cases, a second layer of underlayment may be applied for additional protection, depending on local codes and manufacturer recommendations. The exact sequencing of drip edge and underlayment at eaves versus rakes follows manufacturer instructions so the system sheds water correctly.
Why this step matters: Correct leak barrier placement in valleys and around penetrations is one of the most important defenses against leaks, since valleys concentrate water flow.
Step 4. Flash all walls and penetrations
Chimneys, skylights, dormers, plumbing stacks, and sidewalls receive new flashing. Step flashing is woven with shingles up sidewalls, counterflashing is set into masonry, and boots or specialty flashings are installed at pipes and vents.
Roofing cement is used to seal around flashing, vents, and other roof penetrations to ensure waterproofing. Many leaks originate at flashing details, which is why quality roofers replace questionable flashing rather than reusing old metal.
Step 5. Lay starter course, field shingles or tiles, and ridge caps
Starter shingles, which are the initial row installed at the roof edge, are essential for preventing water infiltration. To apply starter shingles, begin by placing them along the eaves before installing the main field shingles. Shingles are then laid in a precise overlapping pattern to ensure proper coverage and weatherproofing. Shingling involves measuring, preparing, and overlapping shingles for both protection and aesthetic appeal. Shingles are fastened in the proper nail zone using a nail gun for efficient attachment. At hips and valleys, shingles are cut clean, and roofing nails are used to secure both the drip edge and the shingles. Once the field is complete, ridge cap shingles finish the peaks and hips. The same step by step principles apply to tile and metal systems, using their product specific fastening patterns and trim pieces.
Step 6. Vent the attic and finish the roof
Your roof needs balanced intake at the soffits and exhaust at the ridge or high on the roof. There are several types of roof vents, including exhaust vents, ridge vents, and powered vents, each serving a specific role in promoting attic ventilation.
A ridge vent is typically installed along the roof’s peak to facilitate airflow and control moisture buildup in the attic. Balanced ventilation helps control heat and moisture, extends shingle life, and supports energy performance.
It is important to properly install new vents and replace vents as needed to ensure effective ventilation and prevent damage. Reputable manufacturers offer calculators to size net free vent area using common rules such as one square foot of ventilation for every three hundred square feet of attic floor area when conditions permit. After vents are installed and sealed, crews perform a complete cleanup and final walkthrough.
Energy efficiency and your new roof
Energy efficiency is an important factor to consider when planning your new roof installation. The roofing materials you choose can have a significant impact on your home’s energy use and comfort.
For example, some asphalt shingles are designed with reflective granules or higher solar reflectance index (SRI) ratings, which help reduce heat absorption and keep your home cooler in the summer. You might also consider a cool roof system, which reflects more sunlight and absorbs less heat than standard roofing, lowering your air conditioning costs.
A professional roofer can help you select the most energy-efficient shingles and materials for your climate and roof design, ensuring your new roof not only protects your home but also contributes to lower energy bills and enhanced curb appeal.
DIY roof replacement versus hiring a professional
A motivated homeowner can learn how to reroof a house and even how to reshingle a roof with patience, safety training, and careful attention to manufacturer instructions. That said, the roofing installation procedure demands proper fall protection, deck repairs, leak barrier placement, precise flashing work, and accurate ventilation sizing.
Many warranties require installation by certified contractors or strict adherence to written specs. If you want a guaranteed roof replacement process with coordinated permitting, site protection, and cleanup, a professional crew gives you predictable results and warranty coverage.
How long does a roof replacement take?
For an average single family home with architectural asphalt shingles, many professional crews complete the roof installation within one to three days, depending on roof size, complexity, weather, and material choice. Larger homes, multiple slopes and dormers, specialty materials, and weather delays extend timelines. Ask your contractor to walk you through their plan so you know what happens before, during, and after installation day.
People Also Ask style answers
- Do I need to be home? You can be home, but expect noise and vibration. A pre job walkthrough covers parking, pets, and access.
- Can a roof be replaced in one day? Many shingle roofs are finished in a day when the weather cooperates and the design is simple. Larger or more complex roofs take longer.
- What should I ask my contractor? Ask about deck repairs, ventilation sizing, leak barriers in valleys and at eaves, flashing replacement, cleanup, and how warranties are registered.
Cost factors to consider
Rather than chase a single number, focus on the drivers. Roof replacement costs can vary widely, with average expenses depending on factors like material tier, roof area and pitch, number of facets and penetrations, removal and disposal of old materials, decking repairs, and local permit requirements.
It’s important to obtain multiple quotes to ensure accuracy and get the best value. Premium options such as upgraded underlayment, enhanced ridge ventilation, or designer shingles add cost but often deliver longer life or better aesthetics. A thorough written estimate should itemize tear off, decking contingencies, flashing and underlayment choices, ventilation approach, and cleanup so you can compare proposals fairly.
Understanding roof warranties
A new roof is a major investment, so understanding the warranties that come with it is essential. Most roofing projects include two types of warranties: a manufacturer’s warranty and a workmanship warranty from your roofing contractor.
The manufacturer’s warranty covers defects in roofing materials like asphalt shingles, underlayment, and other components, while the workmanship warranty protects you against installation errors. When reviewing your options, make sure your roofing company provides clear documentation outlining what is covered, how long the coverage lasts, and any maintenance requirements needed to keep the warranty valid.
Pay special attention to coverage for shingles, flashing, and other critical parts of your roof system. Regular roof inspections and prompt roof repair can help you maintain your warranty and ensure your new roof delivers lasting protection for your home.
Caring for your new roof after installation
- Keep gutters clean so water flows freely and does not back up under edges.
- Trim overhanging branches that rub shingles and drop debris.
- Schedule regular inspections after heavy storms and every couple of years to catch small issues early.
- Check attic ventilation and insulation levels to reduce heat buildup and moisture.
- Register your shingle and system warranties and keep records of materials and dates. Manufacturers make registration simple and encourage homeowners to complete it right after installation.
Reroofing over existing shingles versus full tear off
You may read about overlaying new shingles over an existing layer. In some cases, a second layer of shingles or underlayment may be installed over the existing layer if the plywood sheathing is in good condition and local codes permit.
This approach is legally permitted in some jurisdictions when structure and deck are sound and only one existing layer is present. However, a full tear off provides a clean substrate, exposes hidden damage, and allows proper leak barrier and flashing upgrades.
If you consider an overlay, discuss code limits, weight, warranty implications, and long term performance before deciding.
A homeowner’s checklist for smooth roof installation
Use this list to prepare, avoid surprises, and ensure quality.
- Confirm scope and schedule. Review the written estimate, materials list, and start date.
- Permits and HOA approvals. Verify your contractor has applied for required permits.
- Site prep. Move vehicles, patio furniture, and yard items. Discuss landscaping protection and access routes.
- Decking plan. Agree on pricing for unexpected deck repairs so decisions are easy on install day.
- Underlayment and leak barriers. Ask which products are used at valleys, eaves, and roof to wall transitions.
- Flashing strategy. Confirm full replacement where appropriate and methods at chimneys, skylights, and sidewalls.
- Ventilation. Request a balanced intake and exhaust design and how it was calculated.
- Safety. Verify crew uses harnesses and follows fall protection standards.
- Cleanup. Confirm magnet sweep, gutter clean out, and haul away.
- Final inspection and warranties. Schedule the walkthrough, receive warranty documents, and register them.
Glossary of common terms
- Drip edge: Metal flashing at roof edges that directs water into gutters.
- Underlayment: Secondary water shedding layer between deck and shingles.
- Ice and water barrier: Self adhering membrane that protects leak prone zones such as valleys and eaves.
- Flashing: Metal or formed components that seal joints at walls, chimneys, skylights, and penetrations.
- Starter strip: First course that seals edges and locks shingles against wind.
- Ridge cap: Shingles or components that cover ridges and hips.
- Balanced ventilation: Intake at soffits and exhaust at ridge that meets net free area requirements.
Where we work
Mountain View Roofing provides roof replacement in San Luis Obispo and guides homeowners through the entire roof installation process from inspection to final walkthrough. We are also serving Paso Robles and nearby areas with the same attention to detail and safety first approach.
Putting it all together
The most reliable roofs are built as systems. A careful tear off reveals the truth about the deck. Robust underlayment and leak barriers keep water out where it tries hardest to enter. Correctly lapped flashing protects every joint. Balanced ventilation keeps the attic dry and cooler, which protects shingles from premature aging. A clean, well staged jobsite and a final walkthrough safeguard your home and your investment.
When you understand each stage, you can evaluate estimates with confidence, plan for a realistic timeline, and verify quality on installation day. If you are ready to begin, Mountain View Roofing will walk you through the process and complete your new roof efficiently and safely.