External Waterproofing Procedure

Exterior Waterproofing

Exterior waterproofing requires excavation to the foundation footing, or the bottom of the foundation.
Regardless of your circumstances, whether you are experiencing seepage or dampness through the walls, exterior waterproofing will always solve your problem. If anyone suggests otherwise, they are trying to sell you a stand-alone interior water control system, this method of de-watering does not waterproof a basement and only prevents floor water.

Never contract for a water control system if dampness, seepage and or cracking on the walls are your concern, as this may result in further damage to your foundation.

Waterproofing the exterior of a foundation completely eliminates water and moisture penetration through the walls into a basement. For a basement to be absolutely waterproof, it needs to have protection from sub-surface water for all of the below-grade walls.

All of this protection must span from grade level down to the foundation footing or a depth deeper than the basement floor. The important difference is in the materials used to waterproof the walls. Most companies are using tar — the same sealant that was being used 20 years ago. Tar is not waterproofing; it is dampproofing. Tar cannot expand and bridge future cracking. Tar very quickly loses it’s elasticity and cracks. With the seal compromised, the whole process leading to water penetration and structural deterioration begins.

We begin by repairing all cracks with a hydraulic cement which expands as it cures, to eliminate the damage. We then apply a portland cement-based waterproofing seal to completely fill any hairline cracks and seal mortar joints.
A second layer, made of an elastomeric membrane, is then applied; this polymer-based sealant remains pliable and expands to bridge any future cracking. This coat sets like rubber and provides an unsurpassed waterproof seal. A.C.C.L utilizes both trowel grade and heat spray-applied membranes. Finally, to obtain superior and permanent protection we hang an extremely durable dimpled Delta –MS membrane.

The plastic-dimpled core provides compressive strength to keep headwater pressure off the face of the wall, and creates a drainage space that allows high capacity flow to the foundation drainage system. The polymeric film provides additional protection to the elastomeric waterproofing membrane.

If you are going to have your foundation excavated, give yourself the peace of mind that comes from hiring a waterproofing company that utilizes the most advanced materials available, and applies them with the experience needed to get the job done right once and for all. There remains a very noticeable difference in a home that has been waterproofed with our process, compared to a home that has been damp-proofed with tar and plastic or other inferior methods.

Successfully blocking the sub-surface water from basement walls is not enough. The water that enters the ground around your foundation will not do just that, disappear, although sometimes it may seem that way.

We must engineer a drainage system to intercept the water that has been blocked by the waterproofing materials. Otherwise the water will cause immense pressure (hydrostatic pressure) to build up outside the foundation walls. Water doesn’t stack very well so it usually finds its way to the area under the basement floor and then rises from under the floor as it tries to seek its own level.

Disastrous floods can, and very often do, occur without a single drop of water penetrating the basement walls. Waterproofing without proper drainage is destined to fail, and vice versa in many cases. You would be better off having good drainage and no waterproofing! (a statement that one-size-fits-all water control system companies would love to sell everyone on).

It’s true that a good roof is not waterproof but since it drains so well, there’s not a problem. Let’s not forget, though, your roof is not surrounded by tons of backfill saturated with tons of water…you get the point. Basement drainage is much more complex. It has to be deeper than the basement floor, which is very deep in the ground.

There are three methods of moving the water that waterproofing has blocked from penetrating the walls:

One method is to install a weeping tile system to the city storm drain. Prior to connecting the new weeping tile, check the condition of the existing tile. It may require a pressure flush to ensure it will work properly. Install new weeping tile. Fill sides, under and above the weeping tile with gravel. (1 cubic foot per linear foot) Back fill grade, tamping approximately every foot.

The second method is installing a pump and a sump pit system.

The third is a gravity drain. A gravity drain is a downhill pipe sloped away from the house drain pipe (weeping tiles). It’s often referred to as a tail line. A gravity drain is the preferred method, but there must be a destination for this pipe, or pipes, well below the basement level to which the water can flow. If there is no such destination on the property nor a city storm drain, the second method of water disposal is unavoidable; a pump and sump pit system must then be used.

Exterior waterproofing and drainage is by far the best protection for a basement. It is used almost exclusively when houses are being built. However, in retrofit (re-doing other systems that failed) situations, older homes with established landscaping, connected utilities, air conditioners, patios, decks, additions, garages, etc., Exterior waterproofing can be at best impractical, if not close to impossible, so other very effective methods must be applied.
For a less expensive approach to correcting a flooding or leaky basement, see the section on interior de-watering systems.

For more information and help determining if exterior waterproofing is best for your situation, please contact usto schedule a FREE inspection and consultation.

Why Exterior Waterproofing?

As stated above, for a basement to be absolutely waterproof, it needs to have protection against sub-surface water for all of the below-grade walls, sealing a wall on the inside traps water within the wall and actually speeds up the deterioration of the wall, which could lead to foundation walls bowing and serious structural damage.

Water concealed below grade can get under the footings in a foundation, and destabilize the structural integrity of your home or business. This can lead to cracked foundation walls and footings, and very costly repairs.

Standing water and heavy moisture can lead to an infestation of mould, mildew and fungus on the joists, studs and sheetrock in the basement, not only can mould lead to wood-rot and costly repairs, it can be quite damaging to your health.

A.C.C.L Waterproofing certified mold remediators will remove the mold spores, mildew, fungus, toxins and dead organic material from all surfaces, apply a superior mold resistant coating, and install a moisture control unit to prevent any recurrent mold growth in the future.

Exterior waterproofing will prevent any water from damaging your home and save you thousands of dollars in the long run. Homeowners should use common sense when hiring a contractor to do exterior waterproofing. Safety must play an important role in this process.

Improper excavation and backfill can lead to personal and/or structural damage. Contractors should be licensed, insured and follow Ontario Building Code and local regulations regarding excavation.