It’s the first question every homeowner asks us, and the honest answer hasn’t changed: nobody can price your roof from a webpage. Anyone who quotes a replacement from a satellite photo and a price chart is guessing with your money. But “it depends” is a lazy answer too. You deserve to know exactly what the number depends on, what real roofs actually cost in Southern California in 2026, and how to turn a ballpark into a written price. That’s what this guide does — using anchors from our own written proposals, the same ones posted on our sample estimates page.

What Drives The Price

Roof size, measured in squares

Roofers price in squares: one square is 100 square feet of roof surface. A 1,800-square-foot roof is 18 squares. It’s the single biggest driver of the total, and it’s the one thing about your roof that never changes.

Material

Composition shingle, concrete tile, clay tile, and TPO are different material costs, different labor, and different lifespans. Tile is heavier, slower to handle, and needs a stronger underlayment system; shingle is faster and less expensive per square. The material choice alone can double a price.

Pitch and complexity

A walkable, simple gable roof and a steep, cut-up roof with valleys, hips, and a dozen penetrations are different jobs at the same square count. Steep roofs need more safety setup, more staging, and more labor hours per square.

Tear-off scope

One layer coming off or three? Tile lift-and-relay, where we save and reset your existing tile, versus full disposal and brand-new material? Tear-off and disposal is real work with real dump fees, and it’s priced in every honest proposal.

Deck condition

The wildcard in every re-roof. The plywood under your roofing can’t be fully judged until the old roof is off. Rotten sheets must be replaced before re-roofing, which is why honest proposals state the deck terms — per-sheet price or included allowance — in writing, up front. Ours do.

Underlayment and system choices

Standard versus upgraded underlayment, ventilation corrections, flashing scope, and metal work all move the number. They also change how long the new roof lasts, which is the number that actually matters.

Access, logistics, and permits

Two-story access, tight side yards, HOA requirements, and permit fees vary across the six Southern California counties we serve. Small line items, but they’re real, and they’re in the total.

Our Own Numbers: What A Square Costs In 2026

Here are the anchors, straight from two complete Mars Roofers proposals you can read in full. Our architectural shingle sample — a single-story Long Beach home, 18 squares, full tear-off, new synthetic underlayment, new metals, and a continuous ridge vent — came to $13,480. That’s roughly $749 per square, all-in: tear-off, disposal, underlayment, shingles, flashing, and ventilation included. Our concrete tile sample — a two-story Orange home, 24 squares, full tear-off, a two-layer synthetic underlayment system, new flashing metals, battens, and new concrete tile — came to $30,350, roughly $1,265 per square, all-in. Read the tile sample estimate line by line and you’ll see exactly where every dollar sits.

Treat those as anchors, not quotes. Two roofs of the same size and material can still land thousands apart once pitch, layers, decking, and access are known. But if a bid you receive is wildly below these anchors, ask what scope is missing — and if it’s wildly above, ask the same question.

Run Your Own Ballpark In A Minute

Our roof cost estimator does the quick math: pick your material, slide to your roof size, set the pitch, and it returns a planning range built on the same per-square anchors above. For the deeper version — how to compare competing quotes without getting burned, and why repair-versus-replace is a cost-per-year question — read the full roof cost guide.

The Part That Is Actually Fixed-Price

Replacement can’t be priced from a webpage, but finding out your number can. A standard Mars Roofers roof inspection is $300: on-roof inspection with a photo-documented condition report, same price for most homes. NRCIA certification inspections are $450, and large or complex roofs — steep, tile, roughly 2,500 square feet and up — are $750, quoted up front. The inspection is how a ballpark becomes a written proposal with the deck terms, scope, and total in the open.

Before You Compare Quotes

Compare scope, not totals: two bids $4,000 apart usually aren’t the same job. Line up underlayment, flashing, ventilation, and deck terms side by side. Ask what’s excluded, ask who actually does the work, and check the license — CSLB #1138550, Mars Construction Industries Corp, takes two minutes to verify.

Ready for your roof’s real number? Call 310.880.9718 and we’ll put an inspector on it — then a proposal in writing, in the same format as the samples on this site.

Every roof reaches a point where repairs stop being maintenance and start being rent — money spent to borrow a little more time from a roof that’s already done. The tricky part is that the point doesn’t announce itself. It shows up as a pattern: the same kinds of problems, in more places, closer together. Here are the nine signs we look for on Southern California roofs when we tell a homeowner the honest answer is replacement, not another repair. One sign by itself might mean nothing. Three or four together almost always do.

The Nine Signs

1. The calendar has caught up with it

Materials have honest lifespans. Composition shingle runs roughly 20 to 30 years. A tile roof’s tile can last 50 years or more, but the underlayment under it — the part that actually keeps water out — is a 20-to-25-year system. Flat roofs land in a similar range depending on material and ponding. If your roof is at or past its number and problems are starting, you’re not unlucky. You’re on schedule.

2. Shingles are curling, clawing, or buckling

Edges that curl up or claw down mean the shingle has lost the flexibility and seal that keep it lying flat and shedding water. A few curled shingles near a worn valley can be a repair. Curling across whole slopes is the material giving up everywhere at once.

3. Granules are collecting in the gutters

Granules are the shingle’s armor — they shed UV and protect the asphalt underneath. A handful after a storm on a new roof is normal. Gutters and downspout splash blocks full of them, and shingles going visibly bald and shiny, mean the surface is wearing out across the whole roof, not in one spot.

4. Shingles keep going missing

One wind-lifted shingle is an afternoon repair. Losing shingles every season means the sealant bonds and the material itself have aged out. Each missing shingle exposes the underlayment and fasteners below it, and the patch is never as good as the surrounding roof used to be.

5. Leaks are showing up in more than one place

A single leak is usually a flashing, a vent boot, or one failed detail — fixable, and worth fixing. Leaks in different rooms, over different winters, are a system telling you it’s failing in multiple places at once. Chasing them one at a time costs more every year and fixes nothing underneath.

6. The deck feels spongy, or the roofline sags

From the ground, look along the ridge and slopes for dips. From the roof, decking that flexes underfoot has absorbed water and lost strength. Sagging and soft spots are structural warnings, not cosmetic ones — and no surface repair fixes the wood under it.

7. Daylight, stains, or growth in the attic

Light coming through the roof boards, dark water trails on the decking, or mold on the underside of the deck all say water has been getting in longer than the ceiling stain suggests. Widespread attic evidence means widespread failure above it.

8. Tile is cracked, broken, or slipped across the field

A handful of cracked tiles from a fallen branch is a tile repair. Breakage and slippage scattered across multiple slopes points to an aging system — and on older tile roofs the real question is the underlayment underneath, which is usually the same age as the tile.

9. The repair bills keep stacking up

Add up the last few years of patching, leak calls, and emergency tarps. If the running total is approaching real money and the roof still isn’t settled, you’ve been paying replacement prices in installments — without getting a new roof. Cost per year of roof life is the only honest math.

When A Repair Still Makes Sense

Plenty of roofs should be repaired, and we say so when it’s true. A roof repair is the right call when the roof is young relative to its material, the damage is localized — one flashing, one valley, one storm-torn section — and the rest of the system is sound. A repair that buys five honest years is money well spent. A repair on a roof with one year left is rent. The difference isn’t the size of the problem; it’s the condition of everything around it.

Not Sure Which Side Of The Line Your Roof Is On?

That’s exactly what an inspection answers. A Mars Roofers roof inspection is $300 for most homes — on-roof, photo-documented, with a written condition report that tells you what we’d repair, what we’d replace, and what we’d leave alone. No pressure either way, because the photos make the argument for us.

If your roof is showing three or more of these signs, call 310.880.9718. We’ll tell you straight — repair or replace — and put it in writing.

When a roof wears out, there are two ways to put the new one on. You can tear the old roof off down to the deck and build the new system on bare wood, or you can leave the old roof in place and install the new one right over it — a roof-over, also called an overlay or a layover. The roof-over is cheaper on the day it’s installed, and that price difference is the whole sales pitch. Here’s why, on almost every house we look at, we recommend the tear-off anyway — and the narrow set of cases where we’ll say an overlay is defensible.

What A Roof-Over Can’t Show You

The deck is the foundation everything sits on, and a roof-over buries it unexamined. Rot, delamination, and water damage don’t announce themselves from the attic in every case — plenty of bad decking looks fine from below and crumbles from above. When we tear off, we see every sheet, and bad wood gets replaced before the new roof goes on. When a roofer overlays, whatever is under there stays under there, and the new roof’s lifespan gets built on it anyway. Trapped moisture between the layers makes it worse: the old roof keeps rotting, quietly, under the new one.

An overlay also telegraphs the old roof’s problems upward. Old shingles that are curled or uneven print through the new layer, shortening its life and its looks. Valleys, flashings, and edges — the details that actually keep water out — are harder to rebuild properly over an existing layer than on a clean deck. Fasteners are another quiet problem: nails for the new layer have to be long enough to reach through two roofs and still bite into the deck, and when they miss or land in softened wood, wind uplift finds them first.

Code And Weight Set Real Limits

California code caps an asphalt shingle roof at two layers total, and no code anywhere allows a new layer over a deck that is deteriorated or water-soaked — which is precisely the condition you can’t verify without tearing off. Many cities and HOAs in Southern California are stricter than the state floor. Tile, for the record, isn’t an overlay material at all: the options are lift-and-relay or full replacement.

Weight matters too. One layer of asphalt shingles weighs roughly 200 to 300 pounds per square. A second layer doubles that dead load on the framing — 24 squares of roofing becomes an extra two to three tons the structure carries every day, for decades. Most framing handles it; some older framing shouldn’t be asked to.

Warranties And Manufacturer Rules

Shingle manufacturers warranty their products installed the way their instructions describe — over a clean, sound, properly prepared deck. A roof-over can reduce or void coverage depending on the manufacturer and the condition of the layer beneath, and shortened shingle life over an old layer is a well-known pattern: the old roof’s heat and uneven surface age the new shingles faster. The money “saved” by skipping tear-off often comes back as years shaved off the new roof.

What An Overlay Does At Resale

Inspectors flag multiple layers, and buyers discount for them — because a two-layer roof means the next roof is a full tear-off of everything, at full tear-off cost, on the buyer’s watch. If you plan to sell, know that roof certifications weigh the whole system; a clean single-layer roof with a verified deck is simply an easier roof to certify, finance, and sell than a layered one with an unknown deck under it.

The Rare Case Where An Overlay Is Defensible

Almost always isn’t always. An overlay can be the honest choice when all of the following are true: the existing roof is a single layer, lying flat and verified sound; the deck condition is known, not assumed; the framing clearly carries the added weight; and the goal is a deliberate short bridge — a few years of service life on a secondary structure, for instance — with eyes open about the trade-offs. What we won’t do is sell an overlay as the equal of a tear-off at a friendlier price. It isn’t, and pretending otherwise is how homeowners end up paying for two roofs and getting one.

How We Price The Wildcard

The standard objection to tear-off is the unknown: what will the deck look like? That’s a proposal problem, and it has a proposal answer. Every Mars Roofers tear-off proposal states the deck terms in writing up front — how many sheets are included or the per-sheet price if rotten decking is found — so the day of tear-off holds no surprises. Read our sample estimates and you’ll see the deck line in plain language, before any signature.

Getting bids on a re-roof? Ask each roofer one question: tear-off or overlay, and why. Then call 310.880.9718 and ask us. We’ll walk your roof, show you the photos, and put the recommendation — and the deck terms — in writing.