Bone Dry Pro Gyp-Cap
Price range: $125.00 through $465.00
Bone Dry Pro Gyp-Cap is a single-component, ready-to-use membrane-forming surface coating engineered for superior moisture mitigation, capable of handling up to 100% relative humidity on gypsum-based substrates.
Use
- Outdoor
- Indoor
Product Info
- 25 Year Warranty
- Handles up to 100% relative humidity on gypsum-based substrates
- Solvent-free
- Allows foot traffic in as little as 60 minutes
Important Documents
Description
Gypsum underlayment is multifamily’s favorite floor — fire ratings, sound ratings, and a dead-flat pour over plywood. It’s also the schedule’s favorite hostage: gypsum is intensely moisture-sensitive, it dusts, and flooring can’t go down until the RH numbers cooperate. Bone Dry Pro Gyp-Cap ends the standoff: a single-component, membrane-forming coating built specifically for gypsum that handles up to 100% relative humidity — and puts trades back on the floor in as little as 60 minutes.
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Multifamily floor assembly: where Gyp-Cap sits
In a multifamily floor assembly, the Gyp-Cap membrane sits directly on the gypsum underlayment, beneath the finished flooring and above the plywood subfloor and joists. Moisture in the gypsum — up to 100% RH — is capped at the membrane, making the layer every unit stands on floorable.
Built for gypsum — because concrete products aren’t
Penetrating concrete sealers are the wrong chemistry for a gypsum pour — Bone Dry’s own Pro sealer spec prohibits gypsum-based underlayments outright. Gyp-Cap is the purpose-built answer: a ready-to-use, solvent-free, membrane-forming surface coating that’s fully compatible with gypcrete over plywood subfloors. The membrane caps moisture at up to 100% RH, locks down gypsum dusting, and gives underlayment and flooring adhesives a surface they can actually grip — with no profiling and no primer required first.
What it does for the floor
| Function | What it means on site |
|---|---|
| CAPS | Moisture mitigation up to 100% relative humidity on gypsum substrates |
| DUSTPROOFS | Locks down gypsum dusting so adhesives bond to the floor, not the powder |
| SPEEDS | Foot traffic in as little as 60 minutes — trades keep moving |
| SIMPLIFIES | No profiling, no primer before underlayment or flooring adhesives; resealable container |
| CLEAN | Solvent-free, single-component, ready to use |
Sixty minutes to a working floor
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Timeline: wet coat to working floor in about 60 minutes
Apply Gyp-Cap by spray or roller — a single one-component coat — and the floor takes foot traffic in as little as 60 minutes. Trades go back on the floor and flooring adhesives go down with no primer needed.
On a multifamily schedule, every closed floor is a stacked delay — drywallers, painters, and trim carpenters all queue behind it. Gyp-Cap applies effortlessly by spray or roller and carries foot traffic in as little as an hour, so a capped floor is a working floor the same morning it’s coated. When the flooring crew arrives, adhesives go straight onto the membrane.
| Gyp-Cap | Conventional gypsum prep | |
|---|---|---|
| RH tolerance | Up to 100% RH | Flooring gated by RH limits and dry-down |
| Primer before adhesives | None needed | Typically required |
| Dust control | Membrane locks the surface | Separate sealer, or it persists |
| Trades back on | ~60 minutes | Gated by product dry times |
| Components | One — ready to use, resealable | Primer + sealer combinations |
Conventional column reflects typical published requirements of gypsum underlayment and flooring manufacturers. Verify against project-specific data.
The tape test
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The tape test: raw gypsum vs. Gyp-capped
On raw gypsum underlayment, the surface dusts — flooring adhesive bonds to the dust, not to the floor. On a Gyp-capped surface the dust is locked down, so the adhesive bonds to the membrane itself.
Every flooring installer knows the pull: press tape to raw gypsum and it comes up wearing the floor. That powder is exactly what the adhesive would have bonded to. On a Gyp-Capped surface the tape comes back clean — the dust is locked inside the membrane, and the bond line belongs to the flooring.
Which product does your substrate need?
| Substrate | Use |
|---|---|
| Gypsum underlayment (gypcrete over plywood) | Bone Dry Pro Gyp-Cap |
| Bare concrete, new or existing | Bone Dry Pro Penetrating Sealer |
| Chemically abated mastic slab | Bone Dry Pro Encapsulator |
Application
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Application steps
- Prep — clean, sound gypsum surface.
- Apply — spray or roller, one ready-to-use coat.
- Walk & floor — foot traffic in about 60 minutes; adhesives go on.
Three steps — no primer, no profiling, no waiting on the pour.
Good to know: Gyp-Cap is one component out of one container — no mixing, no ratios, and the container reseals between units, which matters when you’re coating a building one floor at a time. Penetrating concrete sealers should never go on gypsum; if your project mixes substrates, run concrete areas with Bone Dry Pro and gypsum areas with Gyp-Cap.
Technical data
| Type | Single-component, membrane-forming surface coating |
| Substrate | Gypsum-based underlayments — gypcrete over plywood subfloors |
| Moisture tolerance | Up to 100% relative humidity |
| Dusting | Protected |
| Application | Spray or roller |
| Foot traffic | As little as 60 minutes |
| Adhesive prep | None — no profiling, no primer |
| Solvents | Solvent-free |
| Container | Resealable |
Pouring gypsum on your next multifamily job? Send us the floor count and square footage — we’ll size the Gyp-Cap order per building. Call 262-694-9748 or email [email protected].
FAQ
Can I use a penetrating concrete sealer on Gyp-Crete?
No. Penetrating sealers react with the free lime and alkali in concrete, and gypsum does not have that chemistry. Gypsum underlayment takes Bone Dry Pro Gyp-Cap, a membrane-forming coating built specifically for it.
What relative humidity can Gyp-Cap handle?
Up to 100% relative humidity on gypsum-based substrates. The membrane caps the moisture at the surface, so flooring is no longer gated by RH limits and dry-down.
Do I need a primer before the flooring adhesive?
No. Gyp-Cap requires no profiling and no primer before underlayment or flooring adhesives; the adhesive bonds to the membrane.
How long before trades can walk on it?
About 60 minutes after application.
Does Gyp-Cap stop gypsum dusting?
Yes. The membrane locks the surface down, so tape pressed to a Gyp-Capped floor comes back clean instead of coated in powder, and the adhesive bonds to the membrane rather than to loose dust.
Is Gyp-Cap a one-part or two-part product?
One part: a single-component, solvent-free, ready-to-use coating with no mixing or ratios. The container reseals between units.
How is Gyp-Cap applied?
One coat by spray or roller over a clean, sound gypsum surface. Foot traffic in about 60 minutes, then underlayment and flooring adhesives go on with no primer.
My building has concrete on the ground floor and gypsum above. What do I use?
Bone Dry Pro on the concrete areas and Gyp-Cap on the gypsum areas. Send us the floor count and square footage of each and we will size the order per building.
Specifications
Read about the specifications here.
Additional information
| Weight | N/A |
|---|---|
| Dimensions | N/A |
| Size | 1 Gallon, 5 Gallon |
