LastiSeal® Concrete Stain and Sealer – Detailed Instructions

Surface Conditions are Critical to Staining Concrete

LastiSeal® Concrete Stain & Sealer combines a waterproofing sealer and concrete stains in one product. While the molecules of the polyester-based sealer will reliably penetrate even into tighter substrates, the color stain pigments have a much harder time. If the surface is not properly prepared, you may end up with concrete that is permanently waterproof but with a color stain that will not last.

DID YOU KNOW? The penetration of water-based stains ranges from 1/32 to 1/16 of an inch.

As with all stains, they depend on being applied to porous materials so that they can readily absorb into the pores. But when stains are applied to smooth or nonporous surfaces, they will not penetrate and will just dry out in a layer on the surface. It may look pretty for a while but since stains are not paints, the stain will easily wear off or wash off.

The key to success is a proper surface preparation and suitable conditions:

  • CLEAN - Free of any oils, grease, dirt, paint, previous sealers, etc.
  • POROUS - Smooth concrete will require acid etching, grinding, or similar.
  • DRY - The concrete must be thoroughly dry. Avoid applying outside if rain is expected within 24 hours.
  • TEMPERATURE - Air and surface temps must be above 60 degrees during and for 24 hours after application.
  • ALKALINITY - Concrete must be well cured with low alkalinity.

"Hard to Waterproof" Materials

For waterproofing purposes, there are materials with large pores that are almost impossible to waterproof — some lightweight CMUs, split face blocks, blocks, and masonry that has severely deteriorated due to extensive water seepage. Even three applications of LastiSeal may not waterproof such materials.

"Hard to Stain" Surfaces

To reiterate, while the waterproofing sealer in LastiSeal penetrates even into tight substrates (up to 4"), penetration of the color pigments is much more difficult (it normally ranges from 1/16 to 1/32 of an inch). LastiSeal® Concrete Stain & Sealer has often been successfully applied to "hard to seal" surfaces but we do not guarantee that the stain will properly absorb and last because there is a great deal of variance among concrete types and conditions.

What surfaces are the toughest to stain?

1. FIBER REINFORCED CONCRETE - Often contains additives that may prevent the proper penetration of pigmented stain.

2. PATCHING COMPOUNDS/SURFACE LEVELERS – Polymer-modified surface levelers are difficult to penetrate.

3. STAMPED CONCRETE - The packed hard surface and release agents used in the stamping process prevent the penetration of stains and penetrating sealers. But there have been successes on well-weathered stamped concrete driveways.

4. CALCIUM CHLORIDE - Additives still sometimes used in cold climates, although controversial. If not properly mixed, it leaves shiny brownish areas which are unsealable.

5. NEW CONCRETE – New concrete is caustic (pH 11) and can break down paints, stains, and adhesives. As it cures, its alkalinity gradually drops but it make take 1 or even 2 years indoors. High pH level can be lowered by acid washing the surface and testing with pH test strips. The target is a pH range of 9 to 6.

Always Test First!

LastiSeal is guaranteed to waterproof concrete for at least 15 years. However, the color stain pigments are much more dependent on proper surface prep, application, and maintenance by the user. Therefore, the color stain itself is not guaranteed!

IMPORTANT: LastiSeal Concrete Stain & Sealer is a Non-Returnable Product!

We strongly recommend that you first test with a small 8-ounce sized bottle of LastiSeal Stain & Sealer. The testing will ensure that you like the color on your concrete and that the stain can properly penetrate into the surface.

Performing the "wet rag test" and "fingernail test" (below) will give you a good idea as to how well the color pigments will absorb.

The Surface Must be Clean and Unsealed

Remove all contaminants like dirt, paints or sealers, curing compounds, adhesives, efflorescence ("white powder"), oil, grease, mildew, rust, and similar. This may require power washing, shot blasting, sandblasting, grinding, scarifying, acid etching, or just washing and scrubbing with a deck brush.

Contrary to popular opinion, acid etching will not remove most paints, sealers, and oils.

Paints:
If you remove the paint from the surface, the pores may be still filed and may prevent proper penetration of LastiSeal. Solvents, thinners, and some strippers fill the pores with the paint instead of lifting it. You may need our professional-strength Lightning Strip Paint and Mastic Remover.

Sealers:
Previously applied concrete sealers which fill the pores in concrete will hinder proper penetration of LastiSeal Concrete Stain and cleaning the surface will not remove them. Contact the manufacturer. Remove curing agents on young concrete.

Acid stained concrete is normally protected with a clear topical sealer, which must be removed first.

Oil:
Deeply embedded oil may be a problem with garage floors even after cleaning or grinding the surface. Use our penetrating degreaser/cleaner Novion Universal Concrete Cleaner (check out Concrete Cleaners). Afterwards, remove any residue with a power washer or rinse it off with water and scrub with a stiff bristle brush.

Efflorescence:
Use our RadonSeal Efflorescence Cleaner (check out Concrete Cleaners) to avoid the hazards of using acids. Then, just let the concrete dry out and sweep the surface before sealing with LastiSeal Stain.

For more information on cleaning and preparing concrete surfaces please check Frequently Asked Questions.

To confirm that the surface is absorbent, use the eyedropper test (see below). If the concrete repels water, LastiSeal® Stain will not able to penetrate.

The Concrete Must be Porous!

To allow the LastiSeal® stain to properly penetrate, the concrete or masonry must be sufficiently porous.

Let new concrete cure for at least a month to fully develop capillaries (pores).

Broom finished concrete (typically found on driveways or sidewalks) is very porous and easy to seal. However, sealers and stains cannot penetrate through a very tight, hard machine-troweled, burnished, or polished concrete surface, common in stores, restaurants, factories, warehouses, and some garages.

Eyedropper test is recommended to confirm the concrete is absorbent. Get an eyedropper in a drugstore (or a drinking straw will do).

  1. Fill an eyedropper with water and add a drop of liquid soap (which breaks surface tension).
  2. Shake thoroughly.
  3. Lay a dozen drops in various areas on the floor.
  4. Observe the behavior of the drops.

If after 10 minutes, the drop is still sitting on the surface or has spread out to leave a large damp spot (the size of a quarter or larger), the surface is not porous enough. If the damp spot is the size of a dime, it is porous enough ("Dime is fine!"). NOTE: All areas will not absorb evenly but at least 70 percent of the drops should meet this test.

Opening up a tight surface:
Your options include vacuum shot blasting, light sandblasting, grinding, sanding, or acid etching. You can avoid hazardous acids by using the organic and environment-friendly EasyEtch Concrete Etcher.

The Concrete Must be Dry

The concrete must be thoroughly dry – dry surface is not good enough. The concrete must be dry inside to allow LastiSeal Sealer penetrate 2 to 4 inches.

Let the concrete dry out for at least two days after a rain or at least three days after pressure washing, depending on temperatures, wind, and humidity. Avoid rain for at least a day after the outdoor application of LastiSeal.

Good ventilation, fans, or dehumidifiers will speed up drying.

Temperatures

The optimal air and surface temperatures for application, as well as of the sealer, is between 65 and 80 °F.

The air and surface temperatures must be above 60 °F (min. 50 °F) but below 100 °F during the application of LastiSeal and for 24 hours afterwards. The surface temperature should remain above 40 °F for at least 24 hours to allow proper curing. This presents no problem in basements — the ground temperature keeps the concrete surface above 50 °F.

The surface cannot be too hot. When outdoors, avoid applying LastiSeal on hot surfaces in direct sunlight which would flash off the sealer before it can penetrate. You can apply LastiSeal® in the morning while the surface is still cool (but avoid dew) or in late afternoon after the surface has cooled (avoiding dew). Or apply it in shaded areas or simply wait for a cloudy day.

Concrete Alkalinity

New concrete is highly alkaline (caustic) — its pH factor is over 12 (much higher than the neutral pH of 7). High alkalinity or acidity "burns off" paints and stains. Color stain pigments then sit on the surface and will easily wear or wash off. As concrete cures and reacts with carbon dioxide in the air or is exposed to acid rain outdoors, its alkalinity gradually drops.

If the concrete is less than two or three years old, particularly when indoors, use concrete pH test strips sold in flooring supplies stores, hardware stores, or online to test its alkalinity.

The pH of concrete must be below 9 (as also required by most concrete paints). If necessary, reduce the pH level by acid washing, then neutralize any residue with baking soda or ammonia solution (when outdoors), thoroughly rinse with water, let dry, and re-test. To avoid the hazards of strong acids, we recommend the citric-acid based EasyEtch Concrete Etcher and pH Reducer.

However, do not to make your concrete too acidic — the pH must be above 6.

Application

Storage

Keep unused sealer in closed containers in protected storage out of direct sunlight at 40–90 °F. KEEP OUT OF THE REACH OF CHILDREN.

Avoid freezing, do not store outdoors in freezing weather.

Shelf life up to 1 year.

Personal Protection

LastiSeal Color Sealer is water-based, non-toxic, nonflammable, non-carcinogenic, and non-hazardous. No hydrocarbon solvents and very low VOCs. No strong odors. Does not harm vegetation or grass.

Using splash goggles is a good industrial hygiene practice. Gloves will keep the sealer from drying on hands. No other special precautionary measures are normally required.

Good ventilation will help remove the evaporating water.

Application Equipment

  • pump-up garden sprayer or a low-pressure sprayer (20–30 psi) equipped with a fan-tip nozzle.
  • paint roller (1/4" mohair or foam roller) to roll out puddles or to use instead of a sprayer indoors.

Application Procedure

Mask glass, metals, and surfaces that should not be stained. When sprayed on glass, wipe off with a wet rag before it dries or clean it later with Novion Universal Concrete Cleaner. LastiSeal does not harm vegetation.

Spray LastiSeal on in a continuous, thick, glistening film and back-roll any puddles with a roller. Spraying is better than rolling particularly on outdoor concrete because it will not leave overlapping roller marks caused by fast drying.

Color Sealer application
Click to enlarge!

When spraying indoors is not practical, you can use a roller. Make sure to deposit a thick enough glistening film like with a sprayer instead of just smudging it on the surface. Maintain a “wet edge” to avoid darker overlap areas. If you must stop during the application, end at a control joint or similar break.

APPLICATION TIPS:
LastiSeal may be applied with a brush or sponge to create design features but heavily enough to also waterproof the concrete.
Staining walls is more difficult than floors because the sealer tends to run down, resulting in an uneven color. When sealing walls, spraying should be followed with a roller to pick up drips and to even out the color.

Keep Stirring!

Do not thin the sealer or dilute with water – it would negatively affect the resulting seal and color.

Upon opening the container, the stain may appear not to be the color ordered. The various color pigments settle unevenly. Stir the contents well especially on the bottom and continue to stir until the pigments have been thoroughly dispersed.

Very important – STIR OR SHAKE WELL BEFORE AND DURING APPLICATION! Stir particularly well off the bottom.

Use another container for mixing: Pour off most of the sealer into a clean container. Then, mix the remainder in the bottom of the container using a kitchen wire whisk or similar. When thoroughly mixed, pour the reserved liquid back into the container and mix it more by pouring the sealer back and forth from one container to another.

Keep stirring while applying the sealer. If using a sprayer, keep shaking it.

Number of Applications

One saturating application is usually sufficient for poured concrete, indoors or outdoors.

Second application may be needed to waterproof a very porous substrate or to achieve a more intense color, particularly with lighter stains. Apply about half an hour after the first application.

Do not Over-Apply!

All the stain must absorb into the surface instead of leaving a film. Too much stain makes it susceptible to hot tire pick-up or it may wash off after a heavy rain or snow melt. In contrast, well-applied LastiSeal Stain cannot be removed with a pressure washer. It is used in truck stops and even a bus depot in sunny Florida.

If uncertain about absorbency of the surface, use only one application as the safer approach.

Coverage

Coverage varies widely depending on porosity:

  • Indoor poured concrete - approximately 200–225 sq. ft./gallon or 1,000–1,150 sq. ft. per 5-gal. pail.
  • Outdoor poured concrete and porous masonry - approximately 150–200 sq. ft./gallon or 750–1,000 sq. ft. per 5-gal. pail.
  • If necessary, use a second lighter application at approximately 250–350 sq. ft./gallon or 1,250-1,750 sq. ft. per 5-gal. pail about half an hour later.

Drying time: Treated surfaces are ready for foot traffic in 3 to 5 hours. Allow at least 3 days before vehicular traffic and 5 to 7 days for heavy vehicles. The sealer fully cures in 1 to 2 weeks.

Cleanup

Wash all tools and equipment with soapy water (Dawn dishwashing liquid recommended) right after the application. Any spills may be cleaned with soap and water before they dry. Flush all spray equipment with soapy solution.

Removing the stain or over-spray: If not yet cured, scrub off using a stiff bristle brush and plenty of water. If already cured after couple days, remove the stain with our Novion Universal Concrete Cleaner. Note this will not remove the penetrating sealer from inside the concrete, which will remain waterproof as well as paintable (except for latex and silicone).

Confirm that the Stain has Penetrated

LastiSeal® Concrete Stain is not a paint and there should be no film left on the surface because it would easily wash or wear off.

When properly applied and cured, LastiSeal stain is difficult to remove. Do the following tests three days after the application:

Wet rag test: Pour on some water, let it sit for couple hours and then, scrub the surface with a wet rag. The stain should not come off! If it does, the stain has not penetrated well enough and would wash off easily.

Fingernail test: There should be no film on the surface. Using a fingernail or similar, confirm that there is no color film to flake off.

What to Do if the Stain Has not Penetrated?

Even in case that the color pigments have no absorbed well, the sealer in LastiSeal has likely penetrated and waterproofed the concrete.

You can remove the color stain by flooding the surface with water and then, scrubbing with a stiff bristle brush. Or use our Novion Universal Cleaner. This will not affect the waterproofing sealer deep inside the concrete.

The best solution may be "locking in" the stain by coating it with a clear acrylic or urethane to protect it against water and wear.

Surface Protection

Since the sealer does not change the surface profile, it has little impact on surface friction. Water may bead on smooth concrete surfaces.

Since the LastiSeal waterproofing component seals deep inside the concrete, it becomes waterproof virtually for life. However, the color pigments remain close to the surface, where they are exposed to wear and tear, and to the weather. Moreover, if the concrete prep was not quite up to par, the LastiSeal color pigments will lay shallow in the surface.

PROTECTIVE TOP COATING:
LastiSeal is a great primer for epoxies, urethanes, and other coatings. Coatings, paints, and floor adhesives bond very well to LastiSeal Sealer except for latex paints (they do not bond chemically) and silicone sealers.

A clear coating will help "lock in" the color stain if it has not fully penetrated and will help protect it against wear, water, snow, salts, and UV-rays. It will also add sheen. There are many clear coatings available in stores – acrylics, urethanes, epoxies, and hybrids, water-based or solvent-based. Solvent-based coatings are usually sturdier but just spray them on instead of brushing to avoid smudging the color.

Maintenance

None required. If you wish to clean the surface occasionally, we recommend a weak solution of Dawn dishwashing liquid in water.

Avoid deicers and rocks salts on outdoor surfaces. They are strong enough to "eat away" plain concrete and would gradually remove the LastiSeal color stain from the surface. Unfortunately, vehicle tires will carry road salt on to the driveway.

Snow shoveling and scraping can damage the concrete surface and the LastiSeal stain. Use a shovel with rubber blade. LastiSeal will make snow and ice slide off.

Deep, visible scratches can be easily touched up with the LastiSeal stain.

Refreshing the color: If the color fades or the surface gets worn say after 5 or 7 years, wash it off with water and mild soap and let dry for couple days. Re-spray with a light application of LastiSeal Stain & Sealer to avoid building up the stain on the surface. It will not absorb very well, because the pores are filled and sealed.

RadonSeal® and LastiSeal® Combination

Waterproofing basement floors or foundation slabs:
For the best possible seal against water, water vapor, and radon gas, seal the slab first with RadonSeal Deep-Penetrating Concrete Sealer. It also neutralizes lime and reduces concrete alkalinity. Let cure for at least five days and brush off any purged efflorescence or minerals.

Then apply then one lighter application of LastiSeal Concrete Stain & Sealer.