Shingle Roof Installation in Los Angeles
New asphalt shingle roofs installed step by step across Los Angeles County, permitted, inspected, and backed by our workmanship warranty. Estimates are free.
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- CSLB #1119699 (C-39)
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Comp Shingle Roof Installation in Los Angeles County
Shingle roof installation is the whole job of putting a new asphalt shingle roof on a house: tear-off, decking repairs, underlayment, flashing, shingles, ridge, and the permit inspections. This page walks through the installation itself. If you are still deciding whether your current roof needs to be replaced, see our shingle roof replacement page.
Comp shingle, short for composition shingle, is another name for asphalt shingle. The photo shows the new gray shingle roof and roof vents on our Covina job, where the old shingles came off down to the decking first.
As a shingle roofing contractor, we handle the permit, the tear-off, and every layer of the new roof. Choosing the shingle itself, including its style, color, and fire, wind, and cool roof ratings, is covered on our asphalt shingle roofing page. If you only need a few shingles replaced, see shingle roof repair.
Required at eaves and rakes
Two layers on 2:12 to 4:12
1/150 of attic area (CRC R806)
CSLB #1119699 (C-39)
Before the Tear-Off: Inspection, Estimate, and Permit
A new shingle roof is planned from the attic up. We walk the roof, look into the attic if there is access, and note anything that will change the job: soft spots in the decking, more than one layer of old roofing, missing drip edge, and how the attic is vented.
Your written estimate then lists the tear-off, how damaged decking will be priced, the underlayment, each flashing to be replaced, drip edge, ventilation work, the shingle product and color, the permit, and cleanup.
Every reroof needs a building permit. Reroofs in the City of Los Angeles with a Class A or B covering that weighs less than 6 pounds per square foot get an LADBS express permit, with no plan check. Outside the city, each city’s building department issues the permit, while LA County Public Works permits work in unincorporated areas. We pull the permit, and the shingle you choose has to meet the fire and cool roof rules for your address.
Tear-Off and Decking: What Old Shingles Hide
Stripping to the deck
A replacement removes every layer of old roofing and underlayment down to the deck, with tarps over the landscaping, windows, and walkways below. Going over an existing roof instead is allowed only in limited cases, which our reroofing page explains. A tear-off lets us see and fix the deck, which an overlay hides.
Replacing damaged decking
Water that got past old shingles often shows up as soft or delaminated decking along the eaves and around chimneys and pipes. On an Altadena shingle replacement, the decking at the roof edge had water damage and was replaced, and our Whittier job went on over new plywood. We photograph damaged areas before adding them to the job.
Covering spaced boards from an old shake roof
Wood shakes and wood shingles were often nailed to boards with gaps between them. The California Residential Code requires asphalt shingles to be fastened to wood structural panels or solid lumber sheathing, so on a house that once had a shake roof, those spaced boards are covered with new sheathing before anything else goes on.
Drip edge at eaves and rakes
The code requires drip edge along the eaves and rake edges of every shingle roof, lapped at least 2 inches and extending at least ¼ inch below the sheathing. Where an old roof had none, the deck edge and fascia often show the damage. We install it as part of the job; adding it on its own is covered under drip edge installation.
Call (877) 557-7778 any time, or use the form below. Office hours are Sunday through Friday, 8 a.m. to 5 p.m.
Underlayment, Flashing, and Shingles in the Right Order
Every layer of a shingle roof laps over the one below it, so water always runs onto the next layer down and never under it. This is the order on the deck:
- Underlayment. It covers the whole deck, and the code calls for a double layer on slopes from 2:12 up to 4:12.
- Valley and wall flashing. Valleys are lined before the shingles go on. Where the roof meets a wall, the code calls for continuous or step flashing, and on a stucco wall the top of that flashing is covered by counterflashing or the stucco itself.
- Starter course. A starter strip along the eaves gives the first row of shingles a sealed, straight edge.
- Shingles. Each course is nailed in the zone the manufacturer marks. The code minimum is four nails per strip shingle, with more wherever the manufacturer’s instructions call for them.
- Pipe boots and roof vents. Each penetration gets a new boot or flashing, worked into the shingle courses as they go up.
- Hips and ridge. Ridge cap shingles or a ridge vent finish the peaks and hips.
Skipped steps, such as reused step flashing or a missing starter course, are hard to see on a finished roof. They usually surface later, as leaks.
Attic Ventilation Under a New Shingle Roof
A reroof is the easiest time to correct attic ventilation, because most of the vents are part of the roof. The California Residential Code requires cross ventilation in an enclosed attic, with a net free vent area of at least 1/150 of the area of the vented space. That can drop to 1/300 when 40 to 50 percent of the vent area sits high on the roof, no more than 3 feet below the ridge, and the rest sits low.
In practice, that means intake vents low at the eaves and exhaust vents high near the ridge, so hot, moist air can leave the attic. We count the existing vent area, then add or replace vents before the shingles go on so the totals meet the code.
Final Inspection, Cleanup, and Warranty
Building inspectors check reroofs at set points. Some cities, Calabasas among them, require a sheathing inspection before the underlayment goes on, and every reroof gets a final inspection. In the City of Los Angeles, the roofing contractor also signs a re-roofing certificate of compliance for the inspector, stating that the work and materials meet the city’s roofing rules.
When the shingles are on, the crew hauls away the debris and sweeps the yard and driveway for nails. In the November-to-March rainy season, each day’s tear-off is planned around the forecast so the opened area can be dried in before the crew leaves. Our shingle roofs carry a workmanship warranty, and Overhead Roofing is an Owens Corning Preferred Contractor and a CertainTeed ShingleMaster credentialed roofing company.
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Get a Price on a New Shingle Roof
Send us your address, a few photos of the roof from the ground, and anything you know about it: its age, past leaks, and how many layers it has. We’ll inspect it and give you a free written estimate. Call (877) 557-7778 with questions.
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Please fill out the form below, or call: (877) 557-7778
Please fill out the form below, or call:
(877) 557-7778
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Don’t wait until a minor issue turns into a significant expense. At Overhead Roofing CA, we make it easy to get expert service fast with no pressure and no hidden fees. From routine roof maintenance to full tear-offs and installations, our team handles every project with precision, honesty, and care.
We specialize in helping LA homeowners and business owners protect their most valuable assets with dependable roofing solutions that last. Our licensed contractors are standing by, ready to inspect your roof, answer your questions, and provide a clear action plan all at no cost to you.
Residential roof repair & replacement
Commercial roofing inspections & upgrades
Emergency leak response & storm damage repair
Financing options available for every budget
Shingle Roof Installation Questions
How long does a shingle roof installation take?
It depends on the roof’s size and pitch, the number of layers to remove, the amount of decking to replace, the inspection schedule, and the weather. Tear-off and decking repair take a large share of the time. Ask for an expected schedule with your written estimate; rain or hidden decking damage can change it, and we let you know when that happens.
What is a comp shingle roof?
Comp is short for composition. A comp shingle roof is an asphalt shingle roof: a fiberglass mat coated with asphalt and surfaced with mineral granules. The two names mean the same thing, so a bid for comp shingle roof installation and a bid for an asphalt shingle roof describe the same kind of roof. Compare the products and scope line by line, not the names.
Can new shingles go over my old shingle roof?
Sometimes, but we rarely recommend it. The code rules out a new layer where two or more layers already exist, where the roof is water-soaked or deteriorated, or over tile. An overlay also hides the deck. A tear-off lets us replace soft decking, add drip edge, and correct the ventilation, which is why we recommend one on most shingle jobs.
When should I replace the whole shingle roof instead of repairing it?
When the damage is no longer limited to one area: shingles cracking or curling on most slopes, granule loss across the roof, leaks in several places, or soft decking. If the roof is sound and the wind damage is on one slope, a repair usually makes sense. After the inspection we say which situation you are in, and if it is a close call, the estimate prices both a repair and a full replacement, and our shingle roof replacement page covers that decision.
How much does a new shingle roof cost?
The price is set after an inspection. The main factors are roof size and pitch, the number of layers to tear off, how much decking needs replacing, the shingle product, flashing and drip edge work, ventilation changes, the permit, and access for the crew and the debris bin. The estimate is free and written, and published regional figures are in our roof replacement cost guide.
What should I check before hiring a shingle roofing contractor?
Look up the license on the CSLB website. It should be active, with the C-39 Roofing classification, a bond, and workers’ compensation on record. Then ask whether the bid includes tear-off to the deck, how decking is priced, new flashing, drip edge, ventilation, and who pulls the permit. Our license is CSLB #1119699 (C-39), and we are BBB Accredited with an A rating.
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