Concrete Companyin Monrovia, CA
A concrete company in Monrovia starts with heights: as we read the Municipal Code, walks and driveways not more than 12 inches above grade are exempt from a building permit, and retaining walls only up to 2 feet. Taller work, slopes and pools need a closer look, so confirm the text with the Building and Safety Division.
Concrete in Monrovia follows a long building history. Lots first went on sale in 1886, building permits hit a record in 1923, and the population reached 20,186 by 1950 and 27,079 by 1960, so a front walk or back patio may sit on ground that has been built on for a century. The city lies in the foothills of the San Gabriel Mountains at 571 feet, and where the ground slopes, flatwork turns into grading.
MDG Builders, CSLB #1040337, is a general contractor in Tarzana: we plan the layout, ask the Monrovia Building and Safety Division which approvals apply and run the schedule, and a licensed concrete subcontractor forms, pours and finishes. Mixes, joints and finishes are covered on our concrete page. The Monrovia overview shows the other trades we manage here, such as decks in Monrovia and flooring in Monrovia.
What Monrovia's code says about concrete work
Where concrete permits come from in Monrovia: City of Monrovia Community Development Department, Building and Safety Division.
- Monrovia exempts walks and driveways not more than 12 inches above grade from permits (Municipal Code 15.04.070), and the zoning code exempts flatwork from neighborhood compatibility design review (17.12.005(G)). Excavation for footings, basements and pools covered by a valid permit is exempt from separate grading rules (15.28.060).
Sources for these rules
Does concrete work like a patio, walk or driveway need a permit in Monrovia?
Possibly not, if the slab stays low. Municipal Code 15.04.070 exempts walks and driveways not more than 12 inches above grade and not over any basement or story below, and the zoning code exempts flatwork from neighborhood compatibility design review (17.12.005). The 2022 model list, by comparison, uses 30 inches, so Monrovia's line is tighter than the state's. The chapter prints its item numbers inconsistently, and we read it on a third-party mirror, so confirm the wording with the City before breaking out an old slab.
Two gaps matter for a driveway. We found no Monrovia text on curb openings or driveway aprons, and the City's site blocked our automated tools, so ask whether a wider opening at the curb needs separate approval. We also did not read the zoning limits on driveway width or front yard paving, so ask Planning before widening.
A permit that is issued lapses if work does not start within 12 months or stops for 12 months (15.04.100), and work done without one costs an investigation fee equal to the permit fee, added to the permit fee (15.04.120).
- How high above the ground will the finished surface sit?
- Does the job touch the curb, the street or a pool barrier?
When does a Monrovia retaining wall need a permit, and what is the 1/3 rule?
Sooner than in most places. Monrovia's building code exempts retaining walls only up to 2 feet, measured from the bottom of the footing, unless they support a surcharge such as a driveway or a building. The 2022 model list sets the line at 4 feet, which is why a wall that needs no permit in one city can need one here. A wall of 6 feet or taller also triggers a Hillside Development permit under 17.12, as the next section explains.
In the RF zone, a retaining wall that extends a pad beside a slope may not exceed 3 feet unless a building screens it (17.12.010(E)(3)). We found no source for a one-third rule of thumb, so we do not print one; the wall's engineer sets the footing and embedment for the actual height and soil.
Plan drainage behind every wall, because water is what pushes a wall over. CSLB's C-8 class covers pouring and finishing concrete and its C-29 masonry class covers concrete block walls, so a block wall and a poured wall can go to different subcontractors.
- How tall is the wall, measured from the bottom of the footing?
- Does it hold back a slope, a driveway or a building?
Do hillside and foothill lots in Monrovia need a grading permit for concrete work?
Often they need something. Monrovia's zoning code on hillside lots requires a Hillside Development permit for new single-family dwellings in the hillside residential zones and for earth movement that creates a footprint over 500 square feet, involves 5 feet or more of cut or fill, or builds a retaining wall 6 feet or taller (17.12.010(H) and 17.12.020(H)). Swimming pools and basements are excluded from that trigger. A terraced patio that cuts into a slope can cross two of those lines at once.
The grading chapter (15.28.060) exempts excavations for footings, basements and pools covered by a valid building permit, and exempts grading less than 12 inches deep only when the City Engineer specifically allows it and the drainage is not redirected or concentrated. Where the property lies in a flood hazard area, Municipal Code 15.48.080 says a permit is required for all proposed construction.
Fire access is its own question. The Fire Code amendment limits road and driveway grades to 10 percent and calls for two ten foot traffic lanes (15.20.280). We could not tell where that applies to an existing driveway, so ask the Fire Department before pouring a steep one.
Ask for the cut and fill figures and the wall height in writing before a foothill pour is priced.
What are the rules for concrete near a pool, a patio cover or a fire pit in Monrovia?
A pool deck brings the barrier rules with it. Chapter 15.16.060 requires a barrier at least 5 feet above grade measured on the side away from the pool, no more than 2 inches between grade and the barrier bottom, and pedestrian gates that open outward, self close and self latch, with the latch at least 4 feet 6 inches above grade. It also requires alarms on doors from the house to the pool area. Pour the deck to the final grade the barrier was designed around, since changing the level later changes the numbers.
On the zoning side, a swimming pool may not sit in the front yard and must be at least 5 feet from side and rear lines, while accessory buildings in the RF, RE and RL zones keep at least 3 feet from those lines (17.12.010, 17.12.020 and 17.12.040(H)). A slab for a patio cover or outbuilding is judged with the structure above it.
Decorative finishes are priced separately from plain slabs. Stamped, stained and exposed aggregate surfaces need sealer and joint planning, so ask which finish the sample board shows and how the sealer is maintained.
- Will the deck level match the grade the pool barrier was designed around?
Can you replace a walk or driveway at a Monrovia landmark or historic district house?
Ask Planning first. Under Municipal Code 17.40.090, no alteration or demolition at a Historic Landmark or in a Historic District may proceed without a certificate of appropriateness from the Historic Preservation Commission, except that the Department reviews certain work at non-contributors. Monrovia has 169 landmarks and two districts, the Wild Rose Tract on the 300 block of Wildrose Avenue and North Encinitas on the 100 and 200 blocks of North Encinitas Avenue.
The design review exemption for flatwork lives in a different chapter from the historic rules, and the text we read does not say which controls a front walk at a designated house. A property 70 years old is a Historic Review Site (17.40.040), so the question is worth asking even off the landmark list.
Breaking out old concrete on a century-old lot can expose pipes, earlier patches and fill that no record describes. With more than 2,500 homes built before 1940, the proposal should say in advance how a surprise under the slab will be priced.
A stamped or colored finish at a designated house is worth showing Planning early.
How much does a concrete company charge for a patio or driveway in Monrovia?
No Monrovia price study turned up, so these are Los Angeles planning figures. Plain patios, walks and slabs of 300 square feet or more run about $8 to $14 per square foot, decorative finishes $15 to $30, and driveway replacement with demolition of the old slab $9 to $20. At those rates a plain 20 by 20 foot patio comes to about $3,200 to $5,600 and a decorative one about $6,000 to $12,000, which is multiplication, not a quote.
Angi's Los Angeles driveway page, dated May 2026, shows $8 to $20 per square foot and an average of $7,270 inside a spread of $3,067 to $16,472. Small jobs price above the per-foot averages because of minimum charges, and retaining walls carry no per-foot figure here: height, footing, steel, drainage and engineering set the price.
Federal wage data give a labor check: cement masons in the Los Angeles area averaged $33.67 an hour in May 2025, according to the Bureau of Labor Statistics. Our concrete page lists the sources, and the written MDG proposal is the real price.
- Is demolition and haul-off a separate line from the new slab?
- What thickness, base and steel does the proposal state?
Concrete details from Monrovia and nearby communities
Photos of forms, rebar and finishes from Monrovia and its neighbors, from low patios to foothill walls. Tap any photo to enlarge it.
What concrete costs around Monrovia
These are Los Angeles planning ranges from the concrete page, not a Monrovia bid. To judge any bidder, the license check guide shows how to look up a CSLB number, and how general contractors use subcontractors explains our role. A proposal should list demolition, base, steel, finish, sealer and any wall engineering as separate lines. The room inside is covered in flooring in Monrovia. For nearby rules, compare concrete in Arcadia, concrete in Pasadena, concrete in Azusa, concrete in Glendale and concrete in Los Angeles.
| What it covers | Typical range |
|---|---|
| Patio, walkway or slab, broom finish, 300 sq ft or more | $8 to $14 per square foot |
| Decorative: stained, stamped or exposed aggregate | $15 to $30 per square foot |
| Driveway replacement, with demolition of the old slab | $9 to $20 per square foot |
| 20 by 20 foot plain patio (400 sq ft) | About $3,200 to $5,600 |
| 20 by 20 foot decorative patio (400 sq ft) | About $6,000 to $12,000 |
| Small jobs under 300 sq ft | Usually above the per-foot range |
| Retaining walls | Set by the written proposal |
Monrovia concrete questions: permits, walls and costs
Can I pour a concrete patio without a permit in Monrovia?
Possibly, if it is low. Municipal Code 15.04.070 exempts walks and driveways not more than 12 inches above grade and not over a basement or story below, and a ground-level patio is similar flatwork. Patios are not named in what we read, so confirm concrete work of this kind with the Building and Safety Division first.
Can I expand my driveway without a permit in Monrovia?
The slab itself may be exempt if it stays within 12 inches of grade, but a wider driveway raises other questions. We found no Monrovia text on curb openings or front yard paving limits, so ask Planning and the Building and Safety Division before widening, and ask whether the City approves the apron at the curb.
Can I build a retaining wall in Monrovia without a permit?
Only a low one. As we read Monrovia's code, retaining walls are exempt up to 2 feet measured from the bottom of the footing, unless they support a surcharge such as a driveway or building. A wall of 6 feet or taller also needs a Hillside Development permit, so get the height confirmed in writing.
What is the maximum height of a retaining wall without a permit in California?
The 2022 model building code exempts walls up to 4 feet from the bottom of the footing to the top, unless they support a surcharge, but each city adopts its own text. Monrovia's code, as we read it, sets the line at 2 feet, so a 3 foot wall that is exempt elsewhere needs a closer look here.
How much should a 20x20 concrete patio cost in Monrovia?
About $3,200 to $5,600 for a plain broom-finish patio and $6,000 to $12,000 for a decorative one, found by multiplying our Los Angeles planning rates by 400 square feet. No Monrovia study turned up. Demolition, base, steel and sealer can add lines, so the written proposal for your site sets the real number.
Is 4 inches of concrete thick enough for a driveway?
Four inches is the thickness commonly named for patios and walks, but we found no code citation for it and treat it as industry practice. A driveway carries vehicles, so ask the contractor to state the thickness, base and reinforcement in the proposal and explain why they suit your soil and the loads.
Does a hillside lot in Monrovia need a permit for concrete work?
It can. Monrovia requires a Hillside Development permit for earth movement over 500 square feet of footprint, 5 feet or more of cut or fill, or a retaining wall 6 feet or taller. Excavation for footings covered by a valid building permit is exempt from separate grading rules, so ask which route your foothill job takes.
Who is allowed to do concrete work in Monrovia, and what license do they need?
A licensed contractor, for any job over the state's $1,000 limit for labor and materials combined, and only an unlicensed person who hires no workers and needs no permit may fall under it. CSLB's C-8 class covers concrete. Penalties for unlicensed contracting reach $15,000 in fines. Look up each license number on the CSLB site.
Do I need approval to replace a walk at a historic district house in Monrovia?
Ask Planning before you schedule it. Municipal Code 17.40.090 requires a certificate of appropriateness for alterations at landmarks and district contributors, and the text we read does not say whether a front walk counts. The Wild Rose Tract and North Encinitas are the two designated districts.
Plan a walk, patio, driveway or wall in Monrovia
Tell us what you want poured, about how big it is, how high it sits above the ground and whether the lot slopes toward the foothills or touches a landmark or district, and we check those first before we price it.