SEMCO Liquid Membrane Basement Waterproofing


Shielding Your Sanctuary: The Complete Guide to Basement Waterproofing with SEMCO Liquid Membrane

Your home is your sanctuary, and at its core lies the foundation, often residing in the basement. This foundational space deserves meticulous protection, making basement waterproofing a critical endeavor. In this comprehensive guide, we'll explore the multifaceted aspects of basement waterproofing, delve into the importance, preventive measures, preparations, and provide a detailed step-by-step guide on using SEMCO Liquid Membrane for an effective defence.

Importance of Basement Waterproofing

1. Structural Integrity

Water damage poses a substantial threat to the structural integrity of your home. It can lead to cracks, instability, and result in costly repairs. Basement waterproofing acts as a proactive measure, ensuring the solidity of your home's foundation.

2. Health and Safety

Damp conditions in the basement can create an ideal environment for mold and mildew growth. This not only compromises indoor air quality but can also lead to various health issues. Waterproofing plays a pivotal role in maintaining a dry and healthy living space.

3. Preservation of Property

Beyond its structural aspects, a dry basement safeguards your belongings. It prevents damage and loss due to water infiltration, preserving the value of your possessions.

4. Expanded Living Space

Waterproofing doesn't merely protect; it opens opportunities. A dry basement can be transformed into additional living areas, enhancing your home's overall functionality and livability.

Ways to Prevent Water Entry Into Your Basement

1. Proper Grading

Ensuring that the ground around your home slopes away is fundamental in preventing water accumulation near the foundation.

2. Gutter Maintenance

Keeping gutters clean and directing water away from the house prevents overflow and seepage into the basement.

3. Downspout Extensions

Extending downspouts to discharge water further away from the foundation minimizes the risk of water infiltrating the basement.

Preparing Your Basement for Waterproofing

1. Assessment

  • Begin by identifying existing issues such as cracks, leaks, or mold in your basement.
  • Plan your waterproofing approach based on the assessment, considering the specific needs of your space.

2. Clear the Space

  •  To facilitate the waterproofing process, remove items from the basement. This ensures unobstructed access to all surfaces.

3. Prep the Surface

4. Repair Cracks and Leaks

  • Fill any cracks or gaps in the walls with an appropriate filler. Any cracks less than 1/4" wide can be applied over with SEMCO Liquid Membrane
  • Address any existing water leaks before applying SEMCO Liquid Membrane to ensure a comprehensive waterproofing solution.

Preventative Measures for Basement Waterproofing

1. Exterior Sealant

  • Applying an exterior sealant to the foundation walls creates an additional barrier against water, reinforcing the effectiveness of basement waterproofing. SEMCO Liquid Membrane can also be used to waterproof exterior foundations.

2. Proper Insulation

  • Ensuring proper insulation helps prevent condensation and reduces the risk of moisture buildup, complementing your waterproofing efforts.

3. Sump Pump Installation

  • Consider installing a sump pump to efficiently manage water accumulation and further fortify your basement against potential flooding.

Step-by-Step Guide to Waterproofing with Semco Liquid Membrane

1. Surface Preparation

  • Clean the basement walls thoroughly, removing any debris and dirt.
  • Ensure the walls are completely dry before the application of SEMCO Liquid Membrane.

2. Seal Cracks and Gaps

  • Use SEMCO Liquid Membrane as a filler to seal any cracks or gaps in the walls, ensuring a comprehensive and watertight application.
  • We highly recommend using the Fabric Reinforcement on any cracks wider than 1/4" and on the joints / seams.

3. Stir SEMCO Liquid Membrane

  • Stir the membrane thoroughly to achieve a consistent color consistency, ensuring optimal performance and color during application.

4. First Coat Application

  • Apply the first coat of SEMCO Liquid Membrane evenly across the walls, covering the entire surface. Allow the first coat to dry to the touch before proceeding to the next step. Depending on humidity and temperature it is normally 1-2 hours, however to be sure do a thumb imprint test by pressing your thumb onto the surface. If there is no imprint, it is ready for the next coat.

5. Second Coat Application

  • Once the first coat is dry enough, apply a second coat of SEMCO Liquid Membrane in order to waterproof your surface. A total thickness of 30-40 mils thickness is required. Typically 1 gallon covers up to 200-250 sq ft at two coats depending on the porosity if the surface.

Benefits of Semco Liquid Membrane

1. Flexibility

  • Adapts to the foundation's natural movement, providing a seamless and durable solution against water infiltration.

2. Durability

  • Forms a robust waterproofing barrier that withstands the test of time, ensuring long-lasting effectiveness in preventing water-related issues.

3. Ease of Application

  • User-friendly formulation makes SEMCO Liquid Membrane accessible for both DIY enthusiasts and professionals, ensuring a hassle-free application process.

4. Versatility

  • Suitable for various surfaces, including concrete, masonry, and wood, offering a versatile solution for different basement structures and even application areas.i

5. Cost-Effectiveness

  • Provides a cost-effective alternative to traditional waterproofing methods without compromising on effectiveness.


Investing in SEMCO Liquid Membrane provides a durable and effective defense against water-related issues, ensuring your basement remains a secure and dry space for years to come. By following these preventative measures and applying Semco, you're actively safeguarding your home from the potential hazards of water damage.