Actichem Pre-Seal 5 ltr

Product Overview

Actichem Pre-Seal — sold by Actichem as Preseal Pro, product code AP171 — is a penetrating pre-sealer applied to stone, masonry and cement products before and during installation, not after it.

Its job is to stop water getting into the material at the point in its life when the material is most vulnerable: during fabrication, transport and the wet trades. Water ingress at that stage is what causes tile warp, picture framing around grout lines, moisture staining from the bed and adhesive, and construction stains that are permanent by the time the site is handed over.

The key design constraint is that a pre-sealer must not interfere with adhesive bond strength. A film-forming sealer applied before installation would compromise the bond. Pre-Seal is a penetrating silane-type treatment that works inside the pore structure, so the adhesive still keys into the substrate.

Why Professionals Use It

• It prevents defects rather than fixing them. Picture framing, tile warp and moisture staining cannot be cleaned off after the fact. They are installation faults, and this is the product that avoids them.
• It does not compromise adhesive bond. That is the difference between a pre-sealer and simply sealing early with a normal sealer.
• Easier grout clean-up. Grout smear releases from a pre-sealed surface far more readily, which saves labour on every tile.
• Vapour permeable. It does not trap moisture in the substrate or hinder the natural passage of water vapour — important on anything laid over a slab.
• Six-sided sealing is supported. Dip-sealing is an approved application method, which is the gold standard for protecting stone against moisture from the bed.
• Cost-effective. It is formulated to work alongside the rest of the Actichem penetrating sealer range rather than duplicate it.

Safety Information — Please Read Before Ordering

The previous version of this page carried no safety information at all. Actichem's current safety data sheet — version 2.2, issued 15 July 2025 — classifies Pre-Seal as DANGER.

Classification

• Signal word: DANGER
• H318 — Causes serious eye damage. Eye Irritation Category 1. This is the top eye category, not eye irritation.
• H315 — Causes skin irritation. Skin Corrosion/Irritation Category 2.
• Poisons Schedule: not applicable
• Not regulated for transport of dangerous goods
• pH 10.5 as supplied.
• Ingredients: potassium methylsiliconate (CAS 31795-24-1) <5%; isopropanol (CAS 67-63-0) <10%; balance withheld as trade secret

What that means on site

• Eye protection is mandatory, and the application method makes it more important, not less. This product is applied by saturating a surface, often by sprayer, often overhead of the operator's hands, and often by people who are dipping tiles. Potassium siliconate at pH 10.5 in an eye is a Category 1 eye damage event. Chemical goggles are the sensible choice over safety glasses here.
• Have an eyewash available. Actichem specifies an eyewash unit. On a fabrication bench or a dip tank, that means a plumbed or bottled eyewash within reach of the operator — not a tap at the other end of the yard.
• Maintain adequate ventilation at all times. Actichem's wording, not a softened version of it. The isopropanol content evaporates during cure, and dip-sealing in an enclosed shed concentrates it.
• Isopropanol is flammable. The product itself is not classified as a flammable liquid and the safety data sheet records the flash point as not applicable, but the solvent flashing off during cure is. No hot work, no smoking, no grinding sparks near a freshly treated batch or an open dip tank.
• Protective clothing. Actichem specifies barrier cream and skin cleansing cream in addition to the usual work clothing.
• Do not use methylated spirits to remove residue while the product is wet near an ignition source — see the residue-removal note below.

If your safe work method statement for pre-sealing was written without a DANGER classification in it, it needs to be redone.

Recommended Substrates

Formulated to protect construction and fine stone, masonry and cement products during fabrication, transportation and installation.

• Marble, limestone and travertine
• Sandstone, granite, basalt and bluestone
• Cement and clay pavers
• Terracotta, Saltillo and quarry tile

How to Use

Read and understand the safety data sheet before use. Always pre-test in an inconspicuous location.

Preparation

• The material surface must be totally clean, dry and free of any chemical residue.
• Do not apply in direct sunlight.
• Apply at temperatures between 10 °C and 28 °C.
• Coverage is 5 to 20 m² per litre per coat, depending on porosity.

Application

1. Apply one coat by generously saturating the surface using a polish applicator, roller or sprayer. Ensure even coverage.
2. Dip-sealing is also an approved method, and is the preferred approach where six-sided protection is required.
3. The surface must remain shiny and wet with a liquid film for at least 30 seconds. Very porous substrates will need more product to achieve this.
4. Allow 5 to 10 minutes for absorption, then remove the excess with a clean dry towel.
5. Ten minutes after the last application, wipe off any sealer remaining on the surface using absorbent toweling or an applicator.
6. Residue that has dried on the surface can be removed by moistening the towel with methylated spirits. Do this in a ventilated area and away from ignition sources.

Curing

• Allow 24 hours before fabrication or installation.
• Keep dry for 12 hours.
• Full cure in 24 to 48 hours.

These times are the whole value of the product. Pre-sealing a batch of tiles and laying them the same afternoon gives you neither the protection nor the bond behaviour you paid for.

Where Pre-Seal Fits in the Sealing Programme

Pre-Seal and a finish sealer do different jobs at different times and are not alternatives to each other.

• Pre-Seal goes on before and during installation. It protects against water, grout, adhesive and construction contamination while the trades are still on site, without compromising the adhesive bond.
• Stone Sealer Pro goes on after installation, once the surface is clean, dry and fully cured. It provides the long-term oil and water repellency the client actually lives with.

On a high-value stone installation, using both is the correct specification. Using only a finish sealer means the material has already absorbed whatever it was going to absorb before you got there.

Mistakes to Avoid

• Applying to a damp or contaminated surface. The material must be totally clean, dry and chemical-free. A penetrating pre-sealer cannot get into pores that are already full of water or saw slurry.
• Applying in direct sun or above 28 °C. The carrier flashes off before the active penetrates, which gives you surface residue instead of protection. On an Australian site this is the most common failure and it is entirely avoidable — work early, work shaded, or work indoors.
• Not keeping the surface wet for the full 30 seconds. On porous terracotta or sandstone you will need noticeably more product than the coverage figure suggests.
• Leaving residue to dry. Wipe it back within the stated window. Dried residue needs methylated spirits and effort.
• Installing before 24 hours. Both the protection and the bond behaviour depend on the cure.
• Treating it as a substitute for the finish sealer. It is not, and the client will notice within a year.
• Working without eye protection because "it is only a pre-sealer". H318.

Technical Specifications

Actichem's safety data sheet lists pack sizes of 5 litres and 15 litres. Carpet Cleaners Warehouse currently stocks the 5 litre pack. Contact us if you need the 15 litre size for a large fabrication run.

Frequently Asked Questions

Will pre-sealing stop my tiles bonding?

No — that is the specific problem this product is formulated to avoid. It is a penetrating treatment, not a film former, so the adhesive still keys into the pore structure. A general-purpose sealer applied before installation would be a different story, and that is why "just seal it early" is not a substitute.

What is picture framing and how does pre-sealing prevent it?

Picture framing is the darker border you sometimes see around the edge of each tile after installation. It is moisture and fines from the adhesive bed and grout wicking into the porous edges of the tile and staying there. Pre-sealing the material — particularly by dip-sealing for six-sided coverage — stops that ingress before it can happen. Once it has happened, it is very difficult to reverse.

What is tile warp and is this really the fix?

Porous tiles that absorb moisture unevenly from a wet bed can distort. Reducing absorption reduces that distortion. Pre-Seal significantly inhibits warping; it is not a guarantee against every combination of tile, bed and site condition, and it does not replace correct bedding practice.

Can I dip-seal rather than brush or spray?

Yes. Dip-sealing is an approved method and gives true six-sided protection, which is the best outcome for high-value stone. Note that a dip tank concentrates the exposure risk — an open bath of a DANGER-classified, pH 10.5 liquid needs ventilation, eye protection and an eyewash close at hand.

Do I still need to seal after installation?

Yes. Pre-Seal protects the material through the build. Stone Sealer Pro provides the long-term stain and oil repellency the finished floor needs. They are complementary, not alternatives.

How much will I need?

Coverage runs from 5 to 20 m² per litre per coat, which is a very wide band because porosity varies enormously between granite and terracotta. Estimate from a test area on the actual material rather than from the midpoint of that range.

What if it dries on the surface before I wipe it back?

Moisten a towel with methylated spirits and work the residue off. Do it in a ventilated area and away from ignition sources. Prevention is easier — set the batch size so you can wipe back within the stated window.

Can I apply it outdoors in summer?

Only within 10 °C to 28 °C and out of direct sunlight. On most Australian summer days that means early morning, late afternoon or under cover. Applying to hot stone gives poor penetration and surface residue.

Related Products

• Actichem Stone Sealer Pro — the finish sealer to apply after installation and cure. Non-hazardous, water based.
• Actichem Stone Soap — the maintenance cleaner for the finished floor.
• Actichem Stone Gel Pro — acid-free cream cleanser for scale and soap scum on stone.
• Actichem Tile & Grout Cream — grout haze and wax removal. Classified DANGER with a reproductive toxicity statement — read that page before use.

Summary

Pre-Seal is the product that separates a stone installation that still looks right in five years from one that was compromised before the grout went in. It stops water, grout and adhesive contamination entering the material during fabrication and installation, makes grout clean-up easier, and does it without compromising adhesive bond.

It is a DANGER-classified product with a Category 1 eye damage statement at pH 10.5, applied by saturation and often by dipping — an application method that puts the operator close to the liquid. Goggles, ventilation and an eyewash within reach are the baseline. Observe the temperature limits and the 24-hour cure, and it will do exactly what it is designed to do.

Safety Data Sheet

Actichem Preseal Pro Safety Data Sheet — version 2.2, issued 15 July 2025

SKU: AP171.05

Planning a stone installation and not sure whether to pre-seal, dip-seal or seal only on completion? Contact Carpet Cleaners Warehouse before you order. The decision has to be made before the material is laid, and it is not one you can revisit afterwards.