Sila-Tek® 3500 Concrete Sealer

An industrial-grade, water-based, sodium densifier for use as a stand-alone product or as a primer to strengthen and harden concrete.

  • Coverage Up to 1,000 square feet
  • Coats 2
  • VOC Content 0 g/L
  • Finish Natural
  • Concentrated One gallon makes four (4) gallons
  • Warranty 100 Year Warranty
3500 Concrete Sealer Bottle Image

Project Calculator*

Sila-Tek 3500 Concrete Sealer marketing image


Sila-Tek 3500 is the most advanced concrete densifier available. This clear penetrating sealer not only densifies and hardens concrete making it up to 50% stronger, but it is the go-to choice to harden and prime basements and driveways. It is also an excellent choice for polishing concrete.


Exceptional when used for:
Not for use on:
  • Bricks, concrete blocks/cinderblocks
  • Polished or extremely smooth concrete surfaces



  • Increases abrasion resistance
  • Strengthens concrete up to 50%


  • No change in appearance
  • Low VOCs


  • UV degradation
  • Excellent penetration

Sila-Tek 3500 Rises Above

Sila-Tek 3500 meets or exceeds the following tests:

  • ASTM C-1353: Abrasion Resistance
  • ASTM C-779: Abrasion Resistance
  • ASTM C-642: Density, Absorption, and Voids
  • ASTM E-303: Surface Frictional Properties
  • OHD L-34: Depth of Penetration

Abrasion Resistance Percentage Improvement vs. Control

Sila-Tek 3500
Sealer Product

Auxilliary Information

  • Technical Specs

    • Feature: Densifier & hardener
    • Chemistry: Sodium silicate
    • Color: Clear
    • Finish: Invisible
    • Category: Penetrating
    • Carrier: Water
    • Availability: Ultra Concentrate: Makes 5 Gallons
    • Packaging: 1 Gallon
    • Coverage: 1000 sq. ft. per coat
    • Reconstitution Ratio: 1 part sealer : 4 parts water
    • Interior/Exterior: Interior/Exterior
    • Application Method: Sprayer, Roller
    • Application Temperature: 45 F - 90 F
    • Number of Coats: 1
    • Drying Time (dry to touch): 6 Hours
    • Drying time (full cure): 24 Hours
    • Time before/after rain: 48 Hours
    • New Concrete: Yes, at least 28 days after being poured
    • Storage/Shelf Life: 1 Year
    • Clean up: Soap/water
    • Paintable: Yes
    • VOC Content: 0 g/L
  • Description

    Sila-Tek 3500 is an advanced, high performance, industrial strength, deep penetrating concrete sealer and densifier designed to strengthen concrete. This unique formula incorporates leading molecular nanotechnology. The subsequent chemical reaction elicited from the formula fills the pores and capillaries with an impenetrable crystallization. Sila-Tek 3500 is a uniquely transparent formula containing a proprietary blend of enzymes and surfactants that aide in accelerating a deeper penetrating disbursement. Thus eliciting a more effective, uniformed chemical reaction between the formula and the concrete substrate it’s being applied to. Sila-Tek 3500 treats and seals from the inside out; strengthening the concrete as well as providing a seal that will not chip, flake, delaminate or breakdown with UV light exposure.

    • Available in an industry first ultra concentrate, 1 gallon of Sila-Tek 3500 mixes with 4 gallons of water to make 5 gallons of sealer that will treat up to 1000 sq. ft. of concrete per coat.
  • Preparation

    Avoid contact with skin, eyes and clothing. Wash hands after use and do not take internally. Please refer to the product Safety Data Sheet (SDS) before using. The preparation process should be followed to ensure adequate penetration and optimum performance:

    Step 1: The concrete substrate must be structurally sound, thoroughly dry and clean. Wait at least 24-48 hours after rain and/or pressure washing before sealing; concrete should be visibly dry.

    Step 2: Remove all paints, previous sealers and/or adhesives before application.

    Step 3: The substrate must be clean of oil, grease, dirt, wax, curing compounds, efflorescence and other contaminants that might interfere with the penetration of the sealer.

    Step 4: If acid is used to clean the concrete, neutralize the surface completely and rinse it with water prior to application. Then wait for the concrete to dry out for at least 24-48 hours.

    Step 5: The surface-zone moisture content of the concrete should not exceed 4%wt.

    Step 6: Cover all surrounding areas not intended to be coated.

    Step 7: New concrete must be cured for at least 28 days before sealing.

  • Appliction

    Step 1: Sila-Tek™ 3500 is a concentrated product that needs to be mixed with water prior to application. We recommend using a five (5) gallon bucket to mix the sealer. Pour the one (1) gallon container of Sila-Tek™ 3500 into a five (5) gallon bucket.

    Step 2:

    • If priming concrete: Next fill up the bucket with four (4) gallons of water (distilled water is preferred*). (Sila-Tek™ 3500 can be mixed in smaller quantities as long as the one (1) part Sila-Tek™ 3500 to four (4) parts water ratio is followed. For example, one (1) cup Sila-Tek™ 3500 can be mixed with four (4) cups of water, or a half (1/2) gallon of Sila-Tek™ 3500 can be mixed with two (2) gallons of water).

    *Distilled water is highly recommended for reconstitution since minerals in tap water can have adverse reactions or cause discolorations in treated concrete. Tap water can be used if first tested for compatibility.

    • If polishing concrete: Next fill up the bucket with three(3) gallons of water (distilled water is preferred*). (Sila-Tek™ 3500 can be mixed in smaller quantities as long as the one (1) part Sila-Tek™ 3500 to three (3) parts water ratio is followed. For example, one (1) cup Sila-Tek™ 3500 can be mixed with three (3) cups of water).

    *Distilled water is highly recommended for reconstitution since minerals in tap water can have adverse reactions or cause discolorations in treated concrete. Tap water can be used if first tested for compatibility.

    Step 3: Stir the Sila-Tek™ 3500 and water mixture well before using.

    Step 4: If spray applying, pour the mixed material into a sprayer. If roll applying, dip a 3/8" nap roller into the bucket of mixed material.

    Step 5: Spray or roll one coat onto an area of approximately 100 square feet.

    Step 6: Immediately apply a second coat to the same 100 square foot area, while the first coat is still wet. You may walk on the first coat to apply the second coat. Apply until the surface is saturated but not to the point of puddling.

    Step 7: Roll or broom out any puddles until the sealer penetrates the substrate.

    Step 8: After the first area has been treated move on to the next 100 square foot section and apply two (2) coats following the wet-on-wet application method.

    Step 9: When the entire application has been treated with two (2) coats, let the concrete dry for at least six (6) hours before walking, 24 hours before driving, and protect the concrete from rain for at least 24-48 hours after sealing. Wait at least 7 days after applying the Sila-Tek™ 3500 before using a top coat sealer or paint.

    Step 10: Clean up: Application tools can be cleaned using soap and water.

    Step 11: If over-spray occurs it should be cleaned and removed immediately after sealing.

    Step 12: Unused or old material may be disposed of in a waste disposal site in accordance with local, state and federal laws.

    Application Notes

    • Before application test the sealer by applying in an inconspicuous area to ensure the desired coverage and appearance is achieved.
    • Do not use on extremely porous concrete or masonry such a hollow concrete block or bricks.
    • Do not over apply. Excess material may result in a white residue or discoloration.
    • Prevent from getting on glazed and finished surfaces such as glass, aluminum etc. In case of contact flush immediately with water.
    • Does not prevent equipment leaks or other leaks such as oil, hydraulic fluid etc. Use the Siloxa-Tek® 8505 or Siloxa-Tek® 8510 for oil repellency and staining resistance.
    • Do not use on concrete that has been previously sealed without chemically etching or mechanically scarifying.
  • FAQ

    What is the difference between the Lithi-Tek 4500 and Sila-Tek 3500? The Lithi-Tek 4500 is of a lithium silicate chemistry, whereas the Sila-Tek 3500 is of a sodium silicate chemistry.

    What do you mix the concentrate with? The Sila-Tek 3500 concentrate is mixed with water. 1 gallon of Sila-Tek 3500 is mixed with 4 gallons of water.

    Can I paint after sealing? Yes, you can paint after applying the Sila-Tek 3500.

    Does the concrete need to be dry before sealing? Yes, the concrete needs to be as dry as possible before sealing. We recommend the moisture content of the concrete be less than 4%wt. It is recommended to wait at least 24-48 hours after rain and pressure washing before sealing.

    My floor turned white after sealing, what happened? This is a common result of over application. Once the concrete reaches its point of absorption any material that was unable to penetrate reacts with the carbon dioxide in the air. This reaction leaves a white, powdery residue on the surface of the concrete. This can easily be removed by sweeping the concrete with a wire brush.

    Why cant I use this product on brick or concrete blocks? This product is not recommended for use on brick because the Sila-Tek 3500 is a penetrating, reactive sealer. Bricks do not contain enough free lime and calcium for the sealer to react with and this causes the bricks to dry with a white, powdery residure. This product is not recommended on concrete blocks because concrete blocks are extremely porous. The best product to seal bricks and concrete blocks is the Siloxa-Tek 8500.

    How many gallons do I need to treat 1000 square feet? You will need 1 gallons to treat 1000 square feet. Each concentrated gallon of Sila-Tek 3500 will cover up to 1000 square feet.

    What can I use to apply this product? The Sila-Tek 3500 can be applied with a garden variety pump sprayer, 3/8" nap paint roller or a brush.

    How do I mix the product with water? The Sila-Tek 3500 is a concentrated product that needs to be mixed with water prior to application. Pour the 1 gallon of Sila-Tek 3500 into a 5 gallon bucket. Next add 4 gallons of water into the 5 gallon bucket. Mix the water and 3500 mixture well. You can then pour the mixture into a sprayer to spray apply, or you can dip a nap paint roller into the bucket and roll apply.

    How do I clean out the sprayer after sealing? Since the Sila-Tek 3500 is a water based product you can use regular soap and water to clean out the sprayer and other application tools.

    Where can I buy this product? The Sila-Tek 3500 is available through a number of distributors found on our distributor page.

Product Comparisons

Uses Concrete Substrates Concrete Substrates
Chemistry Sodium Silicate Lithium Silicate
Carrier Water-Based Water-Based
Finish Natural Natural
Color Clear Clear
Application Method Sprayer, Roller Sprayer, Roller
VOC Content 0 g/L 0 g/L