Harbor Costa Mesa Concrete takes a patched 1950s bay floor out whole and puts one slab back, cut free of the footing and struck level to the apron. Every estimate is measured and written on site.
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Inside the bay
A garage floor in a Costa Mesa tract has usually been cut into more times than it has been swept. The original slab went down with the house in the 1950s with nothing under it, and in the seventy years since it has been opened for a water heater pad, a drain, a laundry line and a sewer repair, each hole filled with a bag mix that set at its own height. The floor that results rocks, dusts and puddles by the door, and no one patch can be fixed without loosening the ones beside it.
Harbor Costa Mesa Concrete was started in 2019 by Julian Mercado after 15 years on flatwork crews across coastal Orange County, and he is in the bay when the saw goes in. The old floor is cut free around its edge so the footing under the walls is never touched, broken out whole and hauled, and the sand under it is compacted before anything goes back. What goes back is one slab, poured in a morning and struck to the three levels a bay meets: threshold, apron, door track.
The work is done under a CSLB C-8 license with liability insurance on every job. A floor in a garage that stays a garage needs no permit under the California Residential Code, but a bay being made into a room needs a building permit from the City of Costa Mesa before the pour, and the barrier under it is inspected first. We file for it and are in the bay for the inspection. Every floor carries a written workmanship guarantee against defects in how it was built.
Reading the old floor
A water heater pad an inch proud of the floor, a sewer trench filled half an inch low, and a lip at every edge between them. Each was poured on a different day into a hole with nothing compacted under it, so each settled its own way. Grinding the lips only thins the weakest concrete.
A gray powder on everything set down in the garage is the surface of a weak slab wearing away one sweep at a time. A 1950s bay mix was lean and finished by hand, and after seventy years the top has worn to the sand in it. A coating will not hold, because what it bonds to comes off.
The low patch inside the roll-up door holds a puddle a day after rain, because the floor was struck to fall out to a driveway that has since been raised. Water sitting on a slab with nothing under it goes into the sand and back up through the surface, so the damp outlasts the rain.
A crack that runs straight across the bay from one wall to the other, and keeps opening, is the slab breaking along the line where two pours of different ages meet. The pieces are settling on sand never compacted under either. The floor is now in parts, and only one slab stops it.
Standard in the bay
Eight things go into every bay floor as standard, and each one answers what seventy years of patching leaves behind: pieces at different heights, sand that was never compacted, and a floor with nothing at all between it and the ground.
The old floor is sawn around its edge so the footing under the walls stays whole, then broken out and hauled to the crusher the same day.
The water heater pad, the trench fill and the doorway patch come out to sand, because a new slab poured around them cracks at their edges.
The sand the tract was built on drains, but it was never compacted under the old floor. It is now, in passes, before the base goes in.
A 15 mil sheet laid on the base with its laps taped, directly under the concrete, so the floor is dry to set a box down on all winter.
The pour is screeded to the threshold, the apron and the door track, with the fall from the back wall running out under the door.
Welded mesh lifted to mid-depth on chairs, so a slab poured as one piece stays one piece if the sand under a corner ever settles.
Two saw cuts divide a two-car bay into four panels the afternoon it is poured, so shrinkage cracks land in the joints and not across the floor.
The surface is troweled dense, cured under a sheet and sealed, and the written guarantee is handed over at the walk-through.
Four ways to build it
Four ways to put a floor in a bay here, judged against what stands on it and what the old floor has become. The cut at the footing, the compaction and the barrier are the same in the first three, so the table is the slab itself, and the last row is patching.
| Option | Suits | Slab and steel | Under the slab | Back in use |
|---|---|---|---|---|
| 4-inch bay floor | Two cars in a 1950s attached bay | 4 inches, welded mesh at mid-depth | 15 mil barrier on compacted base | 7 days for the cars |
| 5-inch truck or lift bay | A work truck, a lift or a boat trailer | 5 inches, number 3 rebar on chairs | 15 mil barrier over 4 inches of base | 7 days, 28 for the lift |
| Workshop floor, ground | A shaping bay or a woodshop on the Westside | 5 inches, mesh, surface ground and densified | 15 mil barrier, edge isolated | 7 days, sealed by day 28 |
| Section cut and repoured | One failed patch in a floor under 20 years old | Matched to the old depth, doweled in | Whatever the old floor was laid on | 3 days on foot, 7 for a car |
A section cut out and repoured costs least and lasts only as long as the floor around it; a workshop floor costs most, because the surface is ground and sealed hard.
Sand and the tract
A bay floor in this city answers to its age before it answers to its load: a house from the twenty years after 1953, and a slab standing on sand that nobody compacted in all of them.
The mesa is a marine terrace of sandy loam, and sand is good ground for a garage floor once compacted, because it drains and does not swell. The tract builders did not compact it. A 1950s bay went down on raked sand, and each trench cut through the floor since was backfilled by hand with the sand that came out, so the patches settle and the floor around them does not. Below the Westside bluff the same happens over silty fill, and it settles more. The new floor goes on compacted sand.
Age is the second. Most of Costa Mesa is a house from the State Streets, Halecrest, Mesa del Mar or Mesa Verde with an attached two-car garage, and most of those bays are rented, so the floor has been cut for a water heater or a washer line by a different plumber under each owner. A landlord replacing one between tenants gets a floor poured on a fixed day and a car on it a week later. A bay becoming a room takes the thickened edge a slab foundation carries.
From the saw to the sealer
Five stages, one crew, and the man who reads the old floor at the estimate is the one running the pour. A bay that is becoming a room has its permit in hand before the saw starts.
Julian Mercado walks the bay, maps the patches, checks the levels at threshold and apron, and lifts a patch to see the sand. The figure is written.
You pick the thickness against what will stand in the bay and take a date. If the bay is converting, the building permit is filed first.
The edge is sawn clear of the footing, the old floor and all its patches go out to the crusher, and the sand is plate-compacted in passes.
Base compacted, the 15 mil sheet laid and taped, mesh chaired, then the concrete placed in one morning and screeded to the three levels.
Joints sawn that evening, the slab cured under a sheet for seven days, sealed, and walked through against the estimate before the cars go back.
Behind the figure
The old floor sets most of the figure and the use sets the rest. Two bays the same size can differ by a day of work once the patches are lifted, which is why nothing is quoted from a photograph. Every estimate is measured and written on site.
A two-car bay on the Eastside or in Mesa Verde is one morning's pour. The patches to lift and the depth of sand to compact set the day before it.
Four bays under one roof are four floors on one estimate, each on its own line, and poured in pairs so tenants keep a space through the week.
A conversion needs a building permit, a barrier inspected before the pour, and the slab set to the house floor rather than the driveway, priced.
A workshop floor is ground flat after curing and densified, which adds two days after the pour and is the one finish here that never dusts.
The visit and the written estimate are free, and the call to book one is returned within 1 business day. (949) 541-4812 or send us a message.
Send the form or call, and someone gets back to you within 1 business day to set a time. Julian Mercado comes to the garage, lifts a patch, checks the levels and writes the figure in the bay, and it is yours to keep either way.
Floors we replaced
Three reviews left on Google, the BBB and Facebook, each about a bay floor rather than a drive or a patio, and each naming what was under the old one when it came out.
“Our College Park garage had five different patches and a lip at every one. Julian lifted one at the estimate and showed us the sand was loose underneath. They cut the whole thing out, compacted it, laid the sheet and poured one floor in a morning. Nothing stored on it has been damp since.”
“I keep a boat trailer in a Westside garage and the old floor had broken into three plates under the axle. They poured it at 5 inches on rebar and struck it level to the driveway so the trailer rolls in without the bump. Eighteen months of the boat sitting on it and not one crack.”
“One of the bays under my fourplex on the Eastside had a crack wall to wall and a low spot that puddled. They did the two bays on that side over three days between tenants, left the other two open, and gave me a separate estimate for each. The new tenant moved in on the day I had promised.”
Before you book
What moves the figure on a bay floor, how long the cars are on the street, when the City is involved, and what is guaranteed once the saw cuts are in, answered for a tract garage here.
The old floor, more than the new one. A 1950s bay with five patches and loose sand under it takes a day of cutting, lifting and compacting before the base goes in; a floor that was still one slab comes out in a morning. After that the thickness follows the heaviest thing that will stand in the bay, and a conversion adds the permit and the inspection. All of it is measured in the garage and written as lines.
About ten days. The old floor comes out on day one, the sand is compacted and the base and barrier go down on day two, and the pour is one morning on day three, with the joints cut that evening. The slab is then kept damp under a sheet for seven days before a car rolls onto it. In a fourplex the bays are done in pairs so half the parking stays open, and a gray coastal morning means the pour is never raced by heat.
Yes. Sawing the edge clear of the footing, breaking out the floor and every patch in it, and hauling it to a crusher are on the estimate, and so is the compaction of the sand underneath. What sits outside the figure is named at the visit, not added afterward: a water heater to be moved and reset by a plumber, a drain line found broken under a patch, or a building permit fee where the bay is becoming a room.
Not to replace the floor in a garage that stays a garage; the California Residential Code treats it as a slab on grade inside the building. The permit arrives when the use changes. A bay converted to a bedroom, a studio or a rental unit needs a building permit from the City of Costa Mesa, and the inspector looks at the barrier and the steel before the pour. We file for it, book the inspection and are there for it.
Rarely. A slab that has settled, dusted or cracked over decades is wear, and a policy treats wear as the owner's to fix. The claim that does get paid is sudden damage: a water heater that burst and washed the sand out from under a patch, or a car that went through the wall and broke the floor with it. Photograph it before anything is cut, keep the plumber's report if there is one, and ask your carrier first.
How it was built. The compaction under it, the barrier, the thickness, the steel, the joint layout and the levels it was struck to are printed on the estimate, and the floor carries a written workmanship guarantee against defects in how it was built. A damp patch coming through a floor we sheeted is ours to fix. Tire marks, a dropped engine block, a leaking car and a coating somebody else applied are not.
A 3,500 psi ready-mix placed the morning it is batched, a 15 mil polyethylene barrier laid directly under the concrete with its laps taped, and welded wire mesh on chairs at 4 inches or number 3 rebar at 5. Under the sheet is 4 inches of compacted crushed base over the compacted sand. Each is named on the estimate, so what comes off the truck and what goes into the bay can be checked against what you signed.
For the estimate and the walk-through, and not in between. The crew needs the bay empty to the walls, the door left open or a code for it, a hose bib and the cars on the street for about ten days. Anything stored in the garage has to be out before the saw starts, because the dust from the cut gets into everything. If a tenant is in the unit we arrange the days with them and send you the same photographs.
Nearby towns
The towns on the list, nearest first, with the distance from the office on Newport Boulevard beside each. A garage floor in any of them is measured in the bay before a figure is written.
Four jobs that are booked with a bay floor or in the same visit, on the same compacted sand, by the same crew, and set out on one written estimate line by line.
The run the bay opens onto, poured to meet the new floor at the door track without a step.
The thickened-edge slab a bay needs when it stops being a garage and becomes a unit.
A polished or stained interior floor over the new slab, for a bay finished as a room.
Sawing the old floor clear of the footing, or opening one patch to look at the sand under it.
Call or send the form and you hear back within 1 business day. Say how many patches are in the floor and what will park on the new one, and the visit can be set for a day in the same week.