Exterior Waterproofing: Basement Waterproofing from the Outside

Exterior waterproofing is the preferred method of waterproofing because it stops water before it ever enters your home.

Waterproofing Questions

  • Is the leak originating from the exterior of your home or the interior of your home?
  • Is water entering from the foundation wall, or through the floor?
  • Are your weeping tile systems working properly?
  • Is there an issue with the sump pump?
  • Are the floor drains clear?

Professional Tip: While excavation is required for proper restoration regardless of the foundation type (Stone, Brick, Block or Concrete) the key principle is to keep water away from the home to begin with.

The #1 Goal of Waterproofing is to Protect Structural Integrity

The first goal of waterproofing is to protect the structural integrity of your home and to keep water and moisture from getting inside your home. External basement waterproofing does just that!

Waterproofing your basement from the outside involves;


  • Excavation
  • Crack Repair
  • Mortar Replacement
  • Waterproofing Membrane Wraps
  • Proper drainage with Weeping Tile Systems
  • Proper grading away from the home
  • Properly installed downspouts

Advantages of Exterior Waterproofing

First, water is dealt with from the outside and never comes into the home. This eliminates moisture problems, maintains air quality, and keeps your basement dry and free from possible mold.

Second, exterior waterproofing protects your foundation from damage and erosion, prevents cracks from hydrostatic pressure, and gives you the peace of mind that even during heavy rainfalls or snow melting, your home is protected.

Third, it makes your basement space comfortable and livable. Without the threat or presence of water, you are free to make a fully livable space in the basement that is not musty, damp or threatened by leaks through the foundation or concrete floor.

7 Basic Steps To Exterior Waterproofing

    1. Exterior excavation and foundation cleaning.
    2. Repair any damaged or broken spots on the block, poured concrete, stone or brick foundation.
    3. ADD FOOTING BEVEL to seal the most vulnerable part of the foundation, where the footing meets the foundation.
    4. Install Aqua-Bloc, Yellow Jacket or BlueSkin waterproof membrane to provide a barrier that keeps water out.
    5. Install Platon Wrap or Waterproof Membrane.
    6. Add a new weeping tile system with gravel & cloth filter to allow water to drain through but not debris.
    7. Finish with added backfill and grade so water drains away from the foundation.

Step 1: Foundation Excavation Starts the Waterproofing Process

Exterior excavation is the starting point of the waterproofing process. Our experienced team knows how to properly excavate around your foundation without causing any exterior or interior damage to your home or foundation.

Excavating to the footings of your home allows waterproofing experts to confirm the exterior waterproofing solution, the integrity of your foundation, and diagnose any additional water issues.

Step 2: Repair and Parge the Foundation

Once the foundation is exposed, damage can be repaired to the outside wall with Parging, which is a thin coat of cement applied directly to the foundation wall.

  • Parging can also be applied for the protection of exposed joints.
  • Parging is sometimes applied above ground as extra protection for the exterior of your home.

In all cases, Parging it is one of the waterproofing system layers.

Step 3: Add Footing Bevel to the Foundation for Better Waterproofing

While parging is useful, an additional bevel of concrete is always required at the most vulnerable part of your home’s exterior:

where the foundation meets the footing.

This point is where many water entry problems are found, so it must be properly repaired and sealed to protect against future water issues.

Step 4: Install Aqua-Bloc OR Blueskin Waterproof Membrane

Aqua-Bloc & Yellow Jacket

Aqua-Bloc is a liquid elastomeric below grade waterproofing product with an emulsified asphalt membrane that sticks to many construction surfaces, such as concrete, stone, brick, wood, metal and polystyrene insulation. Stay Dry will often apply it in multiple coats, depending on the situation, along with a reinforcing fabric such as Yellow Jacket, which is a glass fabric weave saturated with synthetic resins. The bright yellow colour helps determine when the fabric is completely covered and embedded with Aqua-Bloc during the application process.

OR Blueskin

Blueskin is a layer of rubberized asphalt self-adhering composite membrane laminated to a Polyethylene film. This application gives your home a long-lasting waterproofing barrier that can stretch to cover new cracks that may develop over time.

Blueskin is applied once the parging is dried. An adhesive primer layer is applied first, with the Blueskin applied on top to ensure a secure hold. Blueskin is a wise choice for waterproofing and repairs as it provides a tough and durable layer of protection for your home against water and dampness.

Step 5: Add a Protective Platon Membrane (Dimple Board)

Platon membranes, or a waterproofing membrane, are essential for any waterproofing project. This dimpled membrane actually provides an air gap between the membrane and your foundation wall through the dimples. This allows any water the makes it past the membrane to drain down to the weeping tile system and be drained away from your home. This membrane provides a physical layer between your foundation wall and water, plus prevents water from being trapped between the membrane and your home’s foundation where it can start to build up as hydrostatic pressure and potentially create cracks in your foundation.

Optional: Protection Board

Protection board is an additional layer that can be applied to protect your waterproofing membrane materials.

This lightweight wallboard is made of a polypropylene co-polymer and gives a layer of protection for your membrane wrap against the elements over time.

Step 6: Install a New Weeping Tile System for better Drainage

Proper drainage and grading are essential for all waterproofing projects. To protect your home from water damage or leakage, the basic principle revolves around keeping water away from your foundation and directed to a set point where it can properly drain. Parging, membranes and crack repairs are great, but without a system to carry water away from your foundation walls, future water problems will likely develop.

Weeping tile systems are efficient in collecting water that drains down the membrane wrap and moving it to a drainage location such as a storm drain or drainage ditch. Filter cloth is placed on the gravel to ensure only water gets into the weeping tiles and not debris that can clog it up.

Step 7: Proper Grading & Backfill Compaction – A Critical Final Step

Finally, grading your property is the last but very important step in the waterproofing process. Ensuring that WATER FLOWS AWAY FROM YOUR FOUNDATION, and not towards your foundation, is a simple but essential principle that ensures your basement will STAY DRY and protected against water leakage when the surrounding soil around your home is saturated with water.