MineralProtect, the mineral sol-gel coating used to seal cement-based tile grout

Technical reference · cementitious grout

The chemistry of sealing cement grout.

The specifier's version. Cement-based grout is, in chemical terms, a thin line of concrete: a Portland-cement paste binding fine silica sand. That one fact decides everything, because it means our coating bonds into grout the same way it bonds into concrete. This page covers what is specific to a cement grout line. For the shared science, how the coating bonds, how it resists real use, and how it beats the old sealers, we link you straight into the deep dives.

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At a glance

Coating & substrate, in brief.

Substrate classCementitious

Portland-cement paste (C-S-H) binding silica sand. Concrete-class chemistry.

CoatingMineralProtect

Water-based inorganic sol-gel. Colourless, non-pigmenting, PFAS-free by design.

Where it worksAt the surface

A thin Si-O-Si network engineered at the surface, roughly 90 to 100 nm, not down the pore.

BondCovalent, into the cement

Condenses genuine Si-O-Si to the cement paste's silanols, as on concrete.

VapourBreathable

Leaves the pore network open, so the grout keeps drying. Framed against films.

Guarantee10-year, registered

Registered per job under the JUMBOGUARD Performance Guarantee.

The substrate

Why grout is a strip of concrete.

Standard sand-and-cement tile grout is a Portland-cement binder holding graded silica sand, the same material family as the concrete under your slab, just finer and laid in a thin joint. Its performance as a substrate follows from three properties.

It's porous, and that's the whole problem

Cement paste is a network of fine capillary pores. Water, and everything dissolved or suspended in it, wicks in. Between two effectively sealed tiles, the grout is the only open, absorbent surface in the field, so it takes the entire staining load: dirty mop water on floors, soap scum and body oil in showers, grease in kitchens, plus Perth's hard-water minerals left behind as the water evaporates.

Its surface carries reactive silanol sites

Hydrated cement paste (calcium silicate hydrate, C-S-H) plus the silica sand present a silanol-rich surface, the same reactive Si-OH chemistry as concrete and, in kind, as glass and quartz. That is what makes a genuine covalent bond possible, rather than mere adhesion. It is why grout, chemically, is a strong substrate for a sol-gel and not a compromise case. The bond chemistry itself is covered in stone and sealer chemistry.

It needs to keep breathing

Cement is alkaline and moves moisture. In a wet area especially, a treatment that blocks vapour can trap water and dissolved salts behind it, driving efflorescence and breakdown at the joint. The correct treatment protects the surface while leaving the pore structure open, which is exactly the behaviour of a thin surface sol-gel rather than a pore-filling film.

The shared science, in brief

Concrete-class, so the science is the same.

Because grout is a thin line of concrete, the mechanism, the four resistances and the head-to-head against legacy sealers are the same on it as on any porous mineral surface. Here they are in brief, each with a link into the full deep dive.

How the bond works

MineralProtect is a water-based, colourless, inorganic sol-gel. Applied thin, it condenses a cross-linked Si-O-Si network at the surface and bonds covalently to the cement paste's own silanols on cure, roughly 90 to 100 nm thin, so the pore stays open and the grout keeps drying. The full mechanism in how sealing works

The four resistances, at the face

A grout line is scrubbed, dosed with cleaner, sometimes sunlit and constantly greased, and every one of those loads acts at the surface where the network sits. It survives the clean and renews by top-up, stays stable through routine alkaline cleaners, carries no chromophore to yellow, and lifts grease instead of letting it set. None of it is immunity, and each carries an honest bound. Each one, with its bound, in the four real-world resistances

Against the alternatives

The wedge over a penetrating impregnator and a topical film is architecture, location and renewal, not the atom. The impregnator strands its repellency below the wear zone and repels water only. The film caps the pore, traps moisture and salts behind it, then blushes, peels and has to be stripped. The full head-to-head in sealer types compared

How durability is measured

The standards, and what we do and don't claim.

Coating durability on this kind of surface is measured as contact-angle retention across recognised wet-scrub and abrasion cycles. We hold to what is measured and scoped, and we flag what isn't.

The methods. ISO 11998 and ASTM D2486 wet-scrub, ASTM D4060 Taber abrasion, with ASTM C813 and D8380 for the glass line. Durability is retention of repellency across cycles, not a one-off bead.
Family evidence. The GlassProtect line still beads above 100 degrees after 3,000 cream-cleanser cycles, about 3 times slower repellency loss than the leading brand in comparable testing. That is glass data, cited as evidence of the sol-gel approach, not a grout figure.
Independently tested. The JUMBOGUARD chemistry is tested and compliant at houses including TÜV Rheinland, SGS, Intertek and REACH.

We do not publish an invented Taber or scrub number for MineralProtect on grout, and we do not borrow the glass retention figures to describe it. The claim is the architecture and the standards, held honestly.

90-100 nm where the protection lives A thin Si-O-Si network at the surface, not millimetres down the pore.

Honest limits

Where the mechanism stops.

It is a treatment, not a permanent fix

A long-lasting surface treatment that degrades slowly and predictably and needs periodic reapplication. Not permanent, not waterproof, not maintenance-free. It makes cleaning faster and far less frequent, it does not remove it.

It protects clean grout, going forward

It cannot pull a stain out of grout that has already discoloured in the pore, and it is not a remedy for cracked, missing or failed grout, which needs regrouting first. Assessment at quote determines which case a joint is in.

Chemical resistance is bounded

Si-O-Si is more resistant, not immune. It is stable at routine-cleaning pH and short contact times, not alkali-proof or acid-proof. Strong acids and neat bleach can still attack cement grout if left to dwell.

Epoxy grout is a different case

Epoxy grout is a resin, effectively non-porous, and rarely needs sealing. The mechanism here is for cementitious grout, the porous, cement-based kind that absorbs and stains.

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