Best Joint Sealants for construction

Benefits of Using waterproofing sealant:

  1. Weatherproofing and Waterproofing

    • waterproofing sealant help protect your home or structure from moisture, preventing water ingress that could lead to mold, rust, or structural damage.
  2. Energy Efficiency

    • By sealing gaps in windows, doors, and walls, joint sealants help reduce air leakage, improving insulation and lowering heating/cooling costs.
  3. Durability and Protection

    • waterproofing Sealant provides long-term protection against dust, dirt, moisture, and pests that might otherwise enter through gaps and cracks.
  4. Flexibility

    • Many waterproofing sealant remain flexible even after curing, accommodating the movement of building materials due to temperature fluctuations, settling, or vibration.
  5. Cost-Effective Solution

    • Sealing gaps and joints is an affordable solution to prevent damage, improving the lifespan of a building and reducing the need for expensive repairs.
  6. Aesthetic Improvement

    • When applied correctly, joint sealants can give a clean, finished look to joints, cracks, and seams, enhancing the visual appeal of a structure.

Common Applications of  waterproofing Sealant:

  1. Construction & Building:

    • Sealing joints in walls, floors, and ceilings, particularly in areas that are exposed to the elements (e.g., around windows, doors, and roofing).
  2. Automotive:

    • Used to seal joints in car bodies, including around windows, doors, and other metal panels, preventing water leaks and corrosion.
  3. Plumbing:

    • Sealing pipe joints and preventing water leakage in plumbing systems, especially around fixtures and faucets.
  4. HVAC Systems:

    • Sealing ductwork and joints in heating, ventilation, and air conditioning systems to prevent air leakage and improve energy efficiency.
  5. Marine and Boat:

    • Waterproofing and sealing joints in boats and other marine structures to protect against water infiltration.
  6. Interior Design & DIY:

    • Filling cracks and joints in drywall, trim, and moldings for a seamless finish.

Sealing with Supex Waterproofing Sealant

Waterproofing sealants must meet different requirements based on joint location and function. Their main purpose is to block air, water, chemicals, and smoke. In addition, they provide thermal and sound insulation. They also improve the visual finish of the structure.

Expansion joints exist between many construction elements. You find them around windows and doors, between floors and walls, in facades, and near tanks. Therefore, joint sealants play a critical role.

Why choose elastic sealing?
Buildings constantly move. First, thermal changes cause expansion and contraction. As temperatures rise, joints compress. When temperatures drop, joints expand. Strong adhesion becomes essential.

Second, structural movement occurs due to settlement, wind, or vibration. Hence, flexible sealants absorb stress and maintain long-term, leak-free performance.  

Benefits of Using Supex Polyurethane Joint Sealants

Supex polyurethane joint sealants deliver reliable, long-term waterproofing for modern construction. They stay elastic for years and easily absorb joint movement. At the same time, they bond strongly to concrete, metal, glass, stone, and masonry. As a result, joints remain air- and water-tight.

Moreover, Supex sealants apply smoothly and tool easily. They require low extrusion force, even in cold weather. They do not sag on vertical or overhead joints. In addition, they cure with a clean, tack-free finish that meets architectural standards.

Furthermore, these sealants resist weather, chemicals, and mechanical stress. Therefore, they perform consistently across many applications, including:

  • Facades and exterior walls

  • Roofs and metal roofs

  • Floors and expansion joints

  • Bathrooms and wet areas

  • Civil and infrastructure structures

As a trusted waterproofing sealant alternative to waterproof silicone, Supex also supports users with technical guidance and hands-on application training.

HOW TO ENSURE GOOD ADHESION with Polyurethane waterproof sealant

Strong adhesion of a waterproofing sealant is vital for effective joint sealing. Without it, water penetrates the joint. Therefore, proper pre-treatment is essential. The added effort and cost are minimal compared to the longer service life gained.

However, primers do not replace joint preparation. First, clean joints thoroughly. Remove dust, dirt, and processing agents. For concrete, grind off laitance and loose particles. Also, ensure the substrate can handle elastic movement. Otherwise, surface cracking may occur. Proper preparation is critical for both waterproofing sealant and waterproof silicone performance.

Achieving Good Adhesion

Porous Substrates

  • Primer seals pores and improves wetting

  • Enhances bonding and blocks water ingress

  • Required for joints with regular water exposure

Non-Porous Substrates

  • Metals & Powder-Coated Metals: Clean surfaces, use activators, apply primers

  • Plastics: Use activators and primers to improve adhesion

  • Glass: Clean carefully with special cleaners to avoid stains

In short, correct surface preparation ensures durable adhesion and long-term waterproofing.

Supex PU 25 Polyurethane sealant

Call / Whatsapp: +91 9699892782

How to use polyurethane waterproofing sealant

To create visually appealing and durable joints, follow a clear and consistent process. The steps below apply to porous substrates such as precast concrete. For non-porous surfaces, surface preparation may differ. However, the remaining application steps stay the same for both waterproofing sealant and waterproof silicone.

Application Steps

  • Surface Preparation
    First, grind the substrate with a wire brush or suitable tool. Then, remove all dust and loose particles.

  • Backer Rod Installation
    Next, insert the backer rod to the required depth. Choose a rod that is 20–30% wider than the joint. Use a blunt tool to avoid damaging closed-cell rods.

  • Masking Tape & Primer
    If clean joint lines matter, apply masking tape securely. After that, apply primer only where the sealant will bond.

  • Sealant Application
    Now, fill the joint with waterproofing sealant, avoiding air pockets. Remove excess material immediately.

  • Finishing
    Finally, remove the tape before skin formation. Smooth the joint with a finishing liquid for a clean, professional look.

Following these steps ensures long-lasting performance and a neat finish with waterproof silicone or polyurethane sealants.

JOINT RENEWAL AND REPAIR with waterproofing sealant

A simple visual check is usually enough to spot failing joint sealing. Cracks, gaps, or loss of adhesion clearly signal the need for replacement. In most cases, joint refurbishment becomes necessary for the following reasons:

Common Causes of Joint Failure

  • Poor workmanship

  • Use of an unsuitable waterproofing sealant

  • Incorrect joint design

  • Higher-than-expected movement or load

  • Sealant reaching the end of its service life

  • Compatibility issues with nearby materials, such as gaskets

  • Exposure to aggressive chemicals

  • Inadequate surface preparation causing adhesion loss

Steps for Joint Replacement

  • Remove Old Sealant
    First, remove the old material. You may leave up to 0.5 mm if adhesion and the substrate remain sound.

  • Check the Substrate
    Next, ensure the joint flanks are strong. Where adhesion failed, mechanically clean the bonding area.

  • Pre-Treat the Surface
    Then, apply the recommended primer to both the substrate and any remaining sealant residue to ensure long-term tightness.

  • Apply the New Sealant
    Finally, use the same sealant type as before. Replace polyurethane with polyurethane and waterproof silicone with silicone. If compatibility caused the failure, consult your Supex representative for the right solution.

Following these steps restores joint performance and long-term waterproofing reliability.

 

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3 Responses

  1. Polyurethane sealants are perfect for construction joints, and I know it now. I will purchase a few of these things and use them for my stone project. It will be great, and I will enjoy this time.

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