Rio Hondo El Monte Concrete scans a slab before sawing it, and cuts trenches, openings and cores at full depth so the thin floor around them stays whole. Every estimate is measured and written on site.
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How a slab is cut here
A cut through a slab is judged by what is left, not by what comes out. The floor around a trench stays in service, a garage being made into a rear unit, a kitchen with a new drain run, a stem wall with a door in it now, and a cut that wanders, breaks out at the edge or stops short leaves that floor cracked where nobody wanted it. So the line is scanned, chalked and cut to full depth in one pass, and the piece comes out in sections that lift rather than rubble.
Rio Hondo El Monte Concrete was started in 2015 by Ismael Duarte, who spent 21 years on the San Gabriel Valley crews first, and he runs the saw on every cut. Most floors in this town were poured in one decade after the war, 3 and a half inches of concrete with no steel in it and sometimes a gas line or a conduit just under the surface, because the tract builder put it wherever was quickest. A blade finds those unless a scanner finds them first.
The cut needs no permit, but what follows it usually does. A new drain under a garage becoming a rear unit, a lateral replaced under the drive or a door cut into a stem wall is filed with the city's Building & Safety Division, and the trench stays open until the inspector has seen the pipe. The cutting is done under a CSLB C-8 license with liability insurance on every job, wet, and carries a written workmanship guarantee against defects in how it was built.
When a saw is the answer
A garage becoming a rear unit needs a bathroom, and the waste pipe has to run under the floor to the lateral at the street. That is a trench 18 inches wide across a slab that stays in use, and a breaker would take out three times the width and crack the rest. It is sawn instead.
A damp line across a garage floor or a driveway that stays dark after the rest has dried is a supply or waste line leaking below it. The pipe has to be reached, which means a strip of slab out over the run and back in afterward, and the strip is cut so the patch goes back square.
A raised-floor house gets a side door, or a garage gets a wider one, and the concrete stem wall under the framing is in the way. The opening is cut with a wall saw to the width on the drawing, plumb at both sides, with the rest of the wall still carrying the house.
A slab poured without control joints, and most post-war ones here were, cracks in a wandering line across the garage or the patio. Cutting a joint beside the crack and sealing both stops it going further. Left alone it opens each summer and lets water at the sand, the urgent part.
In every cut
Eight things are in every cut at no separate line, and each answers what a slab in this town does: hides pipe and conduit inches under the surface, carries no steel to hold an edge together, and sits on sand that runs into any trench left open overnight.
A ground radar pass along the line finds rebar, conduit and pipe before the blade does, and the line moves if something is under it.
Every cut is snapped from the drawing and checked square to the walls, because a trench cut skew leaves a patch that never matches.
The blade is set to the slab's thickness plus half an inch, so the piece parts clean instead of breaking back under the edge.
Water on the blade keeps silica dust out of the air, and the slurry is drawn off into a drum rather than washed into the street gutter.
A cut section comes out as slabs on a bar or a lifter, so the concrete each side is not pounded and the sand under it is not disturbed.
Sand here holds no face, so a trench is dug, the pipe laid and inspected, and it is closed or shored the day it is opened.
Holes are drilled into the cut edges and rebar set in them, so the patch poured back is tied to the old floor and cannot drop.
The dust and slurry go with us, the floor is hosed, and the written guarantee for the cut and the patch is handed over on the walk-through.
Four kinds of cut
Four tools for four shapes of cut on a lot here, set against what each opens and how deep it goes. The scan, the water and the vacuum are the same in all four, so the table is about the blade and the hole it leaves behind.
| Option | Opens | Depth per pass | Finish left | Back in use |
|---|---|---|---|---|
| Walk-behind flat saw | Trenches and strips through a floor | Up to 6 inches with a 20-inch blade | Straight, square edge | Same day, once the patch cures |
| Wall saw on a track | Doorways and windows in a stem wall | Up to 12 inches from one side | Plumb edge, ready to frame | Framed the next day |
| Diamond core drill | Round holes for pipe and vents | Any depth, 2 to 12 inches across | Smooth bore, no patch needed | Straight away, nothing cures |
| Hand-held ring saw | Corners and tight spots inside | Up to 10 inches, no over-cut | Square corner, no run past the line | Same day as the flat saw |
The flat saw does most of the work in this town; the core drill is the one that leaves nothing to patch. A ring saw is slow and used only where nothing else reaches.
Slabs and lots
Two things decide a cut here and neither is the saw: slabs poured 3 and a half inches thick with nothing in them, and lots so small that the floor being cut is the one the house is living on.
The houses that filled El Monte after the war went up fast on lots of 5,000 and 6,000 square feet, and their garage floors, patios and drives were poured thin and plain. That concrete is past 60 years old, brittle, and carrying whatever the builder ran beneath it, often galvanized water pipe an inch under the surface with a gas line beside it. A breaker on a floor like that shatters it well past the hole, so nothing here is opened without a scan or wider than the saw line.
Size is the second. On a lot that small the garage is the one room a family can add, and the state's ADU rules mean a great many are becoming rear units. Every one needs a drain trench across the floor to the lateral, a water line, and often a door where a wall was, all through a slab that stays as the floor of the new unit. That is most of the cutting done in this town now, and it is done so the floor is kept. Where the slab is too far gone, we pour the garage floor new instead.
From call to patch
Five stages, the same two people at each, and the one who scans the floor is the one on the saw. Where a pipe goes into the trench the permit is filed before the blade touches the floor.
Ismael Duarte measures the run from the drawing, scans it with ground radar and marks what is under it. The figure is written before he leaves.
You choose between a trench, an opening or a core against the table above, and any permit for what goes into the cut is filed first.
The line is snapped and checked to the walls, the saw is set to full depth, and the cut is made wet in one pass with the slurry drummed.
The pieces come out on a lifter, the sand is dug for the pipe or the footing, and the trench is shored or closed the same day.
Rebar is drilled into the edges, the patch is poured flush and broomed to match, and the paperwork is handed over on the walk-through.
Behind the number
The line starts the figure and what is under the slab finishes it. Two trenches the same length can be a day apart once the scan finds a gas line on the route, so nothing is quoted from a photo. Every estimate is measured and written on site.
A drain trench across a garage to the lateral is set by its length and by whether the patch goes back or the whole floor goes new for the unit.
A duplex or a house with a rear unit often shares a lateral, so a trench for one runs under the other's yard, and both owners are on the plan.
Replacing an old clay lateral means a strip out of the drive and the walk, and a cut in the public walk is its own permit and inspection.
A doorway in a stem wall is set by its width and by what the wall carries, since a header may have to go in before the concrete comes out.
The scan and the written figure cost nothing, and the call to fix a time for them comes back within 1 business day. (626) 774-7973 or send us a message.
Send the form or call, and someone rings back within 1 business day to set a time. Ismael Duarte scans the floor, marks what is under it and writes the figure at your house, and you keep the paper as long as you need to decide.
Slabs we cut
Three reviews left on Google, Facebook and the BBB, each about a cut through a slab rather than a slab poured new, and each naming what the cut was for and how the floor came through it.
“We were turning the garage into a unit for my parents and needed a bathroom drain run across the floor to the street. They scanned it, found a gas line on the path and moved the trench a foot over. Sawn, plumbed, inspected and patched inside four days and the floor is flat.”
“The water bill doubled and there was a dark line across the driveway. Ismael cut a strip over it two feet wide, found the old galvanized pipe split, and had the strip poured back before the weekend. You have to look hard now to see where the cut was made.”
“We wanted a side door out of the old house and the stem wall was solid concrete. The wall saw cut it plumb to the framing in an afternoon with the house sitting right on top. No dust in the house at all, and the inspector passed it on the first visit.”
Before you book
What decides the figure, how long a floor is open, whether the city is involved, what a policy pays when a pipe under the slab fails, and what is guaranteed once the patch is in, for a slab here.
Because of the length of the line, what the scan finds under it, and what is poured back. A ten-foot trench across a clear garage floor is a morning; the same trench with a gas line on the route is rerouted and a day longer. Then the patch decides the rest, since a strip poured back flush is far less work than a whole floor replaced for a new unit. All three are seen at the visit and written down.
A day for the cut itself, and the trench is never left open overnight. A drain run across a garage is sawn and lifted in a morning, the pipe goes in that afternoon, and the trench is shored or backfilled before the crew leaves, because sand here slumps into an open trench overnight. Where the inspector has to see the pipe, it is boarded over until then. The patch is poured the next day and walked on the day after.
The scan, the cut, lifting the pieces out and hauling them, the trench where there is one, the dowels and the patch poured back, all as one figure. It also covers the water, the slurry drum and the clean-up, because a cut left as a puddle of gray mud is not finished. What sits outside it is named at the visit, the plumbing itself, a lateral broken further along, or a floor the scan shows is too thin to keep.
The cut on its own, no. What goes into it nearly always does. A new drain, a replaced lateral, a water line or a doorway in a stem wall is a permit from the city's Building & Safety Division, and the trench stays open until the inspector has seen the pipe or the header. A cut in the public walk or the curb is a separate permit from the city's Public Works Department. We file whichever applies and meet them.
Often, for the cut and the patch, and almost never for the pipe. Most California policies exclude the failed pipe itself but cover the cost of getting to it, the cutting, the trench and the concrete poured back, when the leak was sudden rather than a slow seep. Photograph the wet line before we cut, keep the plumber's report, and claim before the patch goes down, because the adjuster wants to see the trench.
The cut and the patch, in writing. What we stand behind is that the cut ran where the drawing put it, at full depth, without breaking the floor around it, and that the patch is doweled to the old slab and does not drop or rock. It is a written workmanship guarantee against defects in how it was built. The pipe in the trench is the plumber's, and a crack that was in the old floor before the scan sits outside it.
A walk-behind flat saw with a 20-inch diamond blade for trenches, run wet from a tank, a track-mounted wall saw for stem-wall openings, a diamond core rig from 2 to 12 inches for pipe and vent holes, and a hand-held ring saw for corners. The scanner is ground-penetrating radar, not a metal detector, so it sees plastic pipe and voids as well as steel. Each tool and the patch mix are named on the estimate.
No. The saw is loud for an hour or two and that is the whole disturbance, and because the cut is made wet there is no dust in the house. The crew needs the room or the garage cleared over the line, a hose bib, and the cars off the drive if the trench crosses it. If the cut is in the kitchen or a bathroom, that room is out of use until the patch has cured, about three days, and we tell you the dates at the visit.
Towns we cut in
The eight nearest towns on the list, with the straight-line distance from the office on Peck Road beside each. Every line is scanned and measured at the property before a figure is written.
Four jobs that follow a cut or need one first, on the same slab or the same lot, done by the same crew and itemized on the one written estimate.
The floor of a converted garage poured new when the old slab is too thin to patch.
A settled corner lifted on piers once the slab over the footing has been opened.
The public walk poured back to city spec after a lateral trench has crossed it.
A footing for the new door's header or an addition, poured in the trench the saw opened.
Call or send the form and you hear back within 1 business day. Say what the cut is for, a drain, a door or a leak, and roughly how far it runs, and the scan can be booked for a day inside the same week.