Glendora Epoxy Flooring provides concrete resurfacing across Glendora, CA and the surrounding cities of Charter Oak, Citrus, San Dimas, Azusa and Covina. Resurfacing occupies the gap between a slab that can simply be coated and one that has to be demolished, and a great deal of the concrete in this area sits in exactly that gap after sixty or seventy years of service.
The question is never really “can it be resurfaced” but “is the slab underneath still doing its job”. A structurally sound slab that has lost its surface is an excellent candidate. A slab that is moving, sinking or cracked through is not, and putting an overlay on it produces the same cracks in the same places within a year.
So we look at what the concrete is doing before we talk about what goes on top of it. What follows is how overlays actually work, what each type is for, and where tear-out is the honest recommendation.
What Resurfacing Actually Involves
Bond Is Everything
An overlay is only as good as its grip on the slab beneath. The existing surface is mechanically profiled with a diamond grinder or shot blaster, all loose and delaminated material is removed, and a bonding primer is applied before the overlay goes down. An overlay placed on a dusty or sealed surface debonds in sheets, and that failure is indistinguishable from the original problem it was meant to fix.
Cementitious Overlays and Microtoppings
Polymer-modified cementitious overlays come in a range of build thicknesses, from a microtopping barely thicker than a coat of paint up to a self-leveling pour that can absorb genuine deviation. The thinner products follow the contour of what is beneath them and refresh a surface, while the thicker ones re-establish a plane. Choosing between them is a decision about how flat the slab is, not about how it looks.
Self-Leveling Underlayments
Where a floor is genuinely out of plane, a self-leveling underlayment is pumped or poured and finds its own level, producing a flat substrate for whatever finish comes next. It needs a properly primed and contained area, since the material will find every gap and low point including the ones you would rather it did not. On an old garage slab that pitches to the door, the pitch usually needs preserving rather than removing.
Shot Blasting Where Grinding Is Wrong
On a large or heavily contaminated exterior slab, a shot blaster opens a uniform profile far faster than a grinder and leaves a texture that suits a cementitious overlay particularly well. It also throws far less airborne dust, since the abrasive and the debris are recovered at the machine. Which tool we bring is decided by the area, the contamination and the finish the overlay needs to key into.
Choosing the Right Repair Route
Resurfacing Against Coating
If the slab is sound and the surface is intact but stained or dull, a coating is the cheaper and faster route. If the surface itself has failed — spalled, pitted, scaled or worn back to aggregate — a coating applied over it will simply follow the damage. Resurfacing rebuilds the plane first, and the coating then has something worth bonding to.
Resurfacing Against Replacement
Replacement is the right call when the slab has lost structural integrity: through-cracking with vertical displacement, sections that rock underfoot, or subsidence from a failure below. Those problems are not surface problems and an overlay hides them for about a season. We would rather quote a tear-out we do not perform than an overlay that fails visibly in a customer’s driveway.
Exterior Resurfacing and Movement
Outdoors, everything is harder. Slabs expand and contract far more, moisture moves through them from below and above, and any overlay has to accommodate that rather than resist it. Control joints are honored straight through the new surface instead of being buried, because a joint filled solid on an exterior slab simply cracks somewhere less convenient within the first temperature cycle.
Drainage, Falls and Standing Water
An exterior slab that ponds water was probably poured that way, and an overlay is a rare chance to correct it. Building falls into a resurfacing job means planning the low points and the depth profile before any material is mixed, and it changes the quantity considerably. Where the fall cannot be corrected within a sensible thickness, we say so rather than producing a flat slab that still holds water.
Finishes Available Over a Resurfaced Slab
Broom, Trowel and Textured Finishes
A resurfaced exterior slab can be finished with a broom texture for grip, a knockdown or spray texture that adds both slip resistance and visual interest, or a smooth trowel finish where the surface will be coated afterward. Texture is a functional choice first — on a pool surround or a sloped driveway the finish is doing safety work, not decorative work.
Stamped and Patterned Overlays
A stamped overlay takes an impression while the material is still workable, producing stone, slate or plank patterns over an existing slab at a fraction of what replacement in the real material would cost. It works best over a large uninterrupted area, and the pattern has to be planned around existing joints rather than run across them and cracked.
Coating a Resurfaced Floor
Where the resurfaced slab is going to be coated, the overlay is finished smooth and left to cure fully before anything else happens. Overlays hold water for a long time and a coating applied too early traps it, so this is a case where the moisture testing regime matters as much as it does on original concrete — arguably more, since the material is new and still releasing.
Color Through the Material Rather Than On It
An overlay can be integrally colored so the pigment runs through the material rather than sitting on the surface as a coating. That matters on a floor that will see wear, because a chip in an integrally colored overlay exposes more of the same color instead of a pale scar. Antiquing and release agents used with stamped work add secondary tones on top of that base.
Getting a Resurfacing Job Right the First Time
Reading the Cracks Before Quoting
Every crack gets assessed rather than counted. Dormant shrinkage cracks are chased and filled and then disappear under the overlay. Working cracks are honored as joints through the new surface. Cracks with vertical displacement between the two sides are a structural signal and change the recommendation entirely, because they mean the slab is moving relative to itself.
Thickness, Feather Edges and Doorways
Every overlay adds height, and that has to be resolved somewhere. Doorways, thresholds and transitions to adjacent flooring all need planning before the material goes down, and a feathered edge taken too thin will chip under traffic. On interior work this frequently decides which product is used, since a door that will no longer close is a poor trade for a flat floor.
Curing, Timing and Getting the Space Back
Cementitious overlays gain strength over days rather than hours, and rushing the return to service is how a new surface gets marked before it has hardened. We give the schedule for foot traffic, furniture and vehicles separately, and on exterior work we plan around wind and direct sun, since a surface drying too fast at the top crazes while the material underneath is still soft.
- 20+ Years Experience
- Every Slab Moisture Tested
- Written System Spec