Basement Waterproofing: What You Need To Know

Basement Waterproofing - What You Need To Know

When it comes to basement waterproofing from the outside or from the inside, the more specific question is: What is the difference between dampproofing and waterproofing your home?

One of the first things we ask homeowners to do when called in for an assessment is to perform a water test from the outside of the house. This water test is essentially turning on a hose and placing it against the area of the home’s foundation. This is done to determine that there is, in fact, a leak in the foundation that is causing water to come in from the outside.

If the water test shows that there is a breach in the foundation and water is coming in, we have to base our quote on whether or not the basement waterproofing can be done from the outside or has to be done internally.

The Benefits of Exterior Basement Waterproofing

RCC External Waterproofing System

External Basement Waterproofing System

Most basement waterproofing problems should be addressed with external excavation because you need to stop water at the source.

Basement waterproofing from the outside will strengthen your foundation and protect it against deterioration. We see different types of foundations here in Southern Ontario: Block, concrete, brick, stone and ICF (Insulated Concrete Forms). This material is what we would refer to as semi-porous material and is not completely waterproof and can crack over time, letting the water seep in from the outside.

There is no way to properly restore the integrity of a foundation without excavating, restoring and sealing a foundation from the exterior. This will also help prevent soil gas and insects from entering your space.

A Step By Step Guide To External Basement Waterproofing

Step 1: Locate The Breach In The Foundation

RCC Inspecting The Foundation Wall For Basement Waterproofing

Inspecting The Foundation Wall

After the water test has been performed and it’s determined that the breach exists in the foundation, the area has to be cleared and prepared for excavation. It is mandatory to call for locates from Ontario One Call (Call Before You Dig) to determine where the underground utility services are. In some cases, the client may have to temporarily relocate an air conditioning unit to clear the way for our crew to get digging or arrange for other obstacles to be moved.

In some cases, the client may have to temporarily relocate an air conditioning unit to clear the way for our crew to get digging or arrange for other obstacles to be moved.

Depending on the type of foundation, we want to make sure that the area we waterproof is at least 5 ft on either side of the problem area.

Step 2: Excavate and Dig To Expose the Footings

Excavating for Basement Waterproofing

Excavation depth depends on the elevation of your property. Most excavations range from 4 to 8 feet deep and approximately 2 ½ feet wide. If we have enough room, we may bring in a machine to expedite the process. Otherwise, the hole is dug out by hand by our experienced crew.

Once the hole has been excavated, shoring is installed to ensure the safety of the workers and prevent any soil from caving into the area dug.

Step 3: Remove and Replace Old Weeping Tile

Remove Clogged Weeping Tile for Basement Waterproofing

Remove Clogged Weeping Tile

Excavation is to the footings where the old weeping tile is removed and new 4 inch weeping tile with filter cloth is installed. The weeping tile is connected to the existing storm sewer.

In older homes, if no existing storm connection is found, it may be necessary to install a sump pump to ensure that the water is moved away from the footing level of the property.

Step 4: Clean and Inspect Foundation Walls for Problem Areas



Foundation walls are then cleaned and inspected for any voids or structural cracks. The defective areas are chiseled out and repaired with non-shrink hydraulic cement which expands when applied to the crevices.

Step 5: Apply the Rubber Membrane To The Exterior Wall

HYDRO GUARD PRO SERIES applied for basement waterproofing.


A trowel on rubber membrane is then applied, which will be the main component to waterproofing your foundation; this product has the elongation which will allow it to expand if any further settlement occurs in the foundation.

We then embed a fabric mesh into the first coat of rubber to strengthen the material before the second coat of rubber is applied.

Step 6: Install High-density Polyethylene Membrane to the Exterior Wall

DMX Drain 5M High-density Polyethylene Membrane for basement waterproofing


We use DMX Drain 5M which is composed of a high-density polyethylene membrane (DMX AG CCMC #13182-R) laminated to a geotextile fabric. The membrane is installed on the foundation wall with the raised dimples placed away from the wall.

Membrane is then fastened to the wall with anchors complete with a caulked termination bar at the top.

Step 7: Install a Layer of Gravel over Weeping Tile

RCC pours a layer of clear gravel over the new weeping tile


After the waterproofing and membrane have been installed a layer of 3/4 inch clear gravel is placed over the weeping tile to maximize the drainage to its fullest potential. The gravel is necessary to ensure that the weeping tile is protected from soil and silt during the backfilling process.

Step 8: Install A Window Well If Necessary

Vertical Weeping Tile Is Installed As Part Of The New Window Well


If your home has any windows below grade and you require a window well, it is installed. We will also install  a 4 inch weeping tile vertically down from the inside of the window well to the footings which is then filled with ¾ clear stone in order to create drainage in the window well, as per the building code.

Step 9: Backfilling and Compaction

RCC Worker is Backfilling and closing up the excavated area


Exterior Waterproofing is complete and the area is backfilled with its native soil and compacted to its original level. You now have fully waterproofed your foundation and will have no further issues with water penetrating into your basement.

RCC offers a one-time free grading service if there minor soil settlement issues and all waterproofing work is guaranteed for 25 years. 

External waterproofing is a big job and should always be handled by professionals. RCC’s external waterproofing system will provide you with a long-term solution, backed by a guarantee that is second to none.

Related: Top 10 Questions To Ask Your Waterproofing Contractor

RCC Waterproofing and Foundation Repairs has been servicing Ontario customers for over 100 years. Their repairs have outlived lifetime warranties by at least two times. The company provides professionally trained sales representatives to view, assess and quote on repairs. The installers are employees of RCC and most have long term working relationships. RCC carries full insurance including WSIB coverage and HST registration.

RCC Waterproofing offers:
  • A Lifetime Waterproofing Guarantee!
  • 24-hour emergency services for Ontario residences
  • Fully trained technical sales representatives to view, assess and quote the repair
  • Over 100 years of third-generation family success both in products and services and superb warranty
  • Full-service options, providing either exterior or interior repairs depending on issues, location, and structure
  • A successful record of servicing over 75,000 customers

To learn more, contact RCC Waterproofing at 416-747-1920 or Toll-Free 1-888-766-2071 or Contact RCC for a Free Inspection