How To Waterproof Foundation Walls From Outside: A Step-By-Step Guide

Foundation walls are the primary defense against water intrusion and moisture-related issues. Waterproofing foundation walls from the outside is a crucial step in ensuring the longevity and integrity of your home’s structure. In this comprehensive guide, we will walk you through the step-by-step process of how to waterproof foundation walls from outside, using industry-standard techniques and materials. By following these steps, you can create a robust moisture barrier that protects your home for years to come.

Step 1: Inspection and Preparation

Before you begin the waterproofing process, inspect the foundation walls for any cracks, holes, or areas of deterioration. Address these issues by repairing and patching the damaged areas using appropriate sealants and repair compounds. Thoroughly clean the surface of the foundation walls to remove dirt, debris, and any existing coatings.

Step 2: Excavation

To access the exterior of the foundation walls, you’ll need to excavate the soil around the perimeter of your home. Use caution to avoid damaging utility lines or other structures. Create a trench that exposes the foundation walls and extends below the frost line to prevent water from infiltrating during freeze-thaw cycles.

Step 3: Surface Preparation

Once the foundation walls are exposed, clean the surface using a pressure washer to ensure proper adhesion of the waterproofing materials. Repair any cracks or imperfections on the surface using appropriate sealants or repair compounds.

Step 4: Application of Waterproofing Membrane

Apply a high-quality waterproofing membrane to the cleaned and repaired foundation walls. Waterproofing membranes are available in various forms, including liquid-applied and sheet membranes. Roll or brush the liquid membrane onto the surface, or adhere the sheet membrane as per the manufacturer’s instructions. Make sure to overlap the edges of the sheet membrane to create a continuous barrier.

Step 5: Protection Board Installation

After applying the waterproofing membrane, install protection boards over the membrane to safeguard it from damage during backfilling. Protection boards are rigid panels that shield the waterproofing layer from rocks, debris, and soil pressure. Secure the protection boards in place using appropriate fasteners.

Step 6: Backfilling

With the protection boards in place, carefully backfill the excavated trench with soil. Compact the soil in layers to ensure stability and prevent settling. Gradually backfill the trench while monitoring the protection boards to avoid any displacement.

Step 7: Grading and Drainage

Once backfilled, ensure that the grading around your home slopes away from the foundation to encourage proper drainage. This prevents water from pooling against the foundation walls and minimizes the risk of water infiltration. Install or maintain a functional gutter and downspout system to direct rainwater away from the foundation.

Step 8: Landscaping and Finishing

With the waterproofing process complete, you can now restore the landscaping around your home. Replant any vegetation, lay sod, or apply mulch as desired. Ensure that the grading remains consistent to maintain effective drainage away from the foundation.

Benefits of Exterior Foundation Waterproofing

Waterproofing foundation walls from outside offers numerous benefits, including:

  • Effective Moisture Barrier: Exterior waterproofing creates a robust barrier that prevents water infiltration and protects the foundation walls.
  • Longevity: Properly waterproofed foundations can last for decades, ensuring the structural integrity of your home.
  • Prevention of Mold and Mildew: By keeping moisture at bay, you reduce the risk of mold and mildew growth within your home.
  • Enhanced Property Value: A well-maintained and waterproofed foundation contributes to the overall value of your property.

Waterproofing foundation walls from outside is a critical step in safeguarding your home against water damage and structural issues. By following this step-by-step guide, you can ensure a moisture-resistant and durable foundation that will stand the test of time. Proper exterior waterproofing not only protects your investment but also provides peace of mind knowing that your home is well-prepared to withstand the challenges of moisture and the elements.