Moisture vapor rising from the ground is the number-one killer of flooring systems, and on a conventional schedule it is also the slowest part of the job: weeks of cure and dry-down, relative-humidity testing, a mitigation coating if the slab fails, then a retest. Bone Dry removes that phase. Bone Dry Pro is sprayed on the fresh slab as soon as it can be walked on, functions as the curing compound, and permanently mitigates moisture in the same pass — flooring goes down on schedule instead of waiting on RH numbers. On a new pour you can also put the waterproofing in the mix with Bone Dry Pro Admix. Existing slabs take Bone Dry Pro on commercial projects, or Original and Plus on residential and smaller jobs.
How do you seal a slab on grade before installing flooring?
Why slabs on grade fail flooring
Concrete looks solid, but it is laced with capillary pores — the highways moisture vapor rides from the ground to the surface. On an untreated slab the vapor keeps climbing until it reaches the flooring adhesive: mold and mildew at the bond line, curling and debonding above it. It emulsifies and weakens the water-, latex-, and acrylic-based adhesives under carpet, vinyl, tile, and wood, which is why the industry gates flooring behind in-situ RH probes (ASTM F2170) and calcium chloride tests (ASTM F1869) and, when the slab fails, an expensive topical mitigation coat over a shot-blasted profile.
A penetrating sealer changes where the problem is solved. Bone Dry Pro penetrates deep into the slab and reacts with free lime and alkali to seal those capillaries permanently, becoming part of the concrete. The vapor path is closed from within, the surface profile is unchanged and ready for adhesives, and a built-in antimicrobial package keeps the pores hostile to mold, mildew, and odor-causing bacteria for the life of the floor.
Three routes to a floorable slab
| Your slab | Use | How it works |
|---|---|---|
| New pour — seal at placement | Bone Dry Pro | Spray as soon as the slab can be walked on; functions as the curing compound; about 300–340 sq ft per gallon on broom-finished, troweled or profiled concrete (350–400 on burnished, polished or Etch-A-Crete-treated slabs); dries in approximately 6 hours, with 12 hours or overnight recommended before flooring (Quick Dry is always included); no RH testing gate; 25-year warranty against moisture-related and bonding failures as the Bone Dry Pro System |
| New pour — waterproofing in the mix | Bone Dry Pro Admix | Dosed at the batch plant or in the truck at 10–12 fl oz per 100 lbs of cement; every cubic inch of the pour is sealed; no spray crew, no onsite F2170 or F1869 testing; lifetime flooring and roofing replacement warranty (onsite rep for pours over 20 yards) |
| Existing commercial slab under flooring | Bone Dry Pro | Etch-A-Crete (a separate prep product) opens hard-troweled surfaces first; then the Pro sealer, applied by our in-house crew or by your contractor with a representative overseeing the work if you want it |
| Existing residential or small-project slab | Bone Dry Original or Bone Dry Plus | Garden-sprayer application; 200–250 sq ft per gallon on broom-finished concrete, 300–350 on machine-troweled concrete, 350–450 on burnished or polished slabs opened with Etch-A-Crete; Plus adds antimicrobial protection for mold-prone spaces |
For a basement or below-grade floor specifically, see Sealing a Below-Grade Concrete Slab. For the whole line at a glance, see the Bone Dry product selector. Comparing sealer types before you choose? See our guide to the best concrete sealer for floors and slabs.
The conventional route versus Bone Dry Pro
| Bone Dry Pro | Typical epoxy moisture-mitigation coating | |
|---|---|---|
| Apply to fresh concrete | Same day as the pour | After cure and dry-down |
| Surface prep on new pours | None — spray and go | Shot-blast to CSP 3 |
| Cures the slab | Yes — functions as the curing compound | No |
| Application | Low-pressure spray, minimal crew | Squeegee or roller, trained crew |
| Turnaround | Dry in about 6 hours; 12 hours or overnight before flooring — Quick Dry always included | Per-coat cure, typically overnight or longer |
| Antimicrobial in the slab | Built in | No |
| Surface profile | Unchanged — penetrates the slab | Adds a film on the surface |
The epoxy column reflects typical published characteristics of two-part epoxy moisture-mitigation systems (ASTM F3010). Verify against project-specific data.
Substrate exceptions
- Gypsum underlayment. Penetrating concrete sealers are the wrong chemistry for gypsum, and the Bone Dry Pro spec prohibits gypsum-based underlayments outright. Upper floors poured with Gyp-Crete over plywood take Bone Dry Pro Gyp-Cap; run concrete areas with Pro and gypsum areas with Gyp-Cap.
- Black mastic or cutback adhesive. After chemical abatement, an aged slab takes Bone Dry Pro Encapsulator, which mitigates moisture and locks in mastic migration in one ready-to-use coat.
- Hard-troweled or burnished existing slabs. Open the pores with Etch-A-Crete before Pro goes on — one coat, a 5–10 minute dwell, then wet-mop or auto-scrub the slab with water to remove the concrete dust the etch creates.
- Patching and leveling. Floor patching and leveling materials over Bone Dry Pro must be cementitious.
- Lightweight concrete. Not an exception — Pro and Pro Admix are formulated for normal-weight and lightweight concrete.
What can go on top
Bone Dry Pro is formulated for all cast-in-place concrete under floor coverings — slab on grade, below grade, and slab on deck — on new and existing slabs, in hospitals, schools, warehouses, and large commercial campuses. It leaves the surface unchanged and ready for carpet, vinyl, VCT, hardwood, and resinous flooring adhesives. Resinous systems (epoxy, urethane, polyaspartic) installed over Bone Dry Pro must be 100% solids over a CSP 3 profile.
Third-party ASTM E-96 and ASTM F-1869 results are available on request. A note on curing specifications: ASTM C-309 covers liquid membrane-forming curing compounds. Bone Dry Pro penetrates the slab instead of forming a membrane, so the standard does not apply to it — used standalone, it achieves the results a curing compound achieves. Where a specification requires C-309 by name, a dissipating curing compound can be applied after the Pro Sealer is applied.
How Bone Dry Pro works on a job
- Tell us the slab. Square footage, slab age, and flooring type — we size the Pro sealer order, recommend Etch-A-Crete separately where the surface needs opening, and arrange application if you want it.
- Spray at placement. As soon as the slab can be walked on, a low-pressure spray at about 300 to 340 square feet per gallon on broom-finished, troweled or mechanically profiled concrete, and 350 to 400 on heavily burnished, polished or Etch-A-Crete-treated slabs. On an existing slab, etch first if it is hard-troweled and degrease oil stains.
- Cure and seal. The same application functions as the curing compound and seals the capillaries — Quick Dry is always included; the sealer dries in approximately 6 hours, with 12 hours or overnight recommended before flooring. Foot traffic and heavy equipment are permitted once the slab is dry to the touch.
- Floor it. No RH testing gate. The Bone Dry Pro System carries a 25-year warranty against moisture-related and bonding failures, and our crew travels nationwide to apply it or a representative oversees your contractor’s application.
Where this applies: This is the slab-under-flooring route used on healthcare facility concrete floors, retail and commercial building concrete floors, university and school building concrete floors and concrete sealers for general contractors. See all the industries we serve.
The Bone Dry Pro route removes the RH testing gate: pour, spray the same day, floor on schedule. With Pro Admix in the mix, onsite ASTM F2170 and F1869 moisture testing is eliminated entirely, because the whole pour is waterproofed rather than tested and then treated.
Used standalone, Bone Dry Pro functions as the curing compound and achieves the results a curing compound achieves, so cure and seal happen in one pass. ASTM C-309 covers liquid membrane-forming compounds and does not apply to a penetrating sealer; where a specification names C-309, a dissipating curing compound can be applied after the Pro Sealer is applied.
Bone Dry Pro dries in approximately 6 hours; 12 hours or overnight is recommended before flooring. Foot traffic and heavy equipment are permitted once the slab is dry to the touch. Quick Dry is always included, and there is no waiting on slab dry-down or on RH probes.
Yes. Both Bone Dry Pro and Pro Admix are formulated for normal-weight and lightweight concrete, and Pro covers slab on grade, below grade, and slab on deck.
Yes. A burnished or hard-troweled surface is effectively sealed shut, so it needs one coat of Etch-A-Crete first — darken the slab completely, let it sit 5–10 minutes, then wet-mop or auto-scrub the slab with water to remove the concrete dust the etch creates. That opens the pores so Bone Dry Pro can penetrate; then apply as normal.
Yes. Resinous systems over Bone Dry Pro must be 100% solids and installed over a CSP 3 profile. Floor patching and leveling underneath must be cementitious.
Bone Dry Pro Gyp-Cap. Penetrating concrete sealers should never go on gypsum; Gyp-Cap is a membrane-forming coating built for it that handles up to 100% relative humidity and takes foot traffic in about 60 minutes. On mixed projects, run the concrete areas with Pro and the gypsum areas with Gyp-Cap.
