How to Waterproof a Basement

Aquaguard Injection & Waterproofing

8 years ago

Introduction

Doing research online and talking to different contractors will surely leave you with more questions than you had when you started out; this article was written to simplify your life by giving you the information you want on how to waterproof a basement – fast.

Many homeowners don’t realize that there are generally two or more basement waterproofing methods available to repair most basement leaks. The waterproofing options are generally governed by the type of foundation on which your home is built.

There are 4 foundation types commonly found in and around the Greater Toronto Area (GTA):

Concrete block (also referred to as cinder block or cinder-block);
Poured concrete;
Double brick; and
Stone.

The type of foundation that you have can usually be determined if you know the year in which your home was constructed or if you can see the foundation walls on the inside of the home.

Traditional Basement Waterproofing – Excavating the Foundation

Traditionally, basement waterproofing involved excavation of the basement and waterproofing of the foundation perimeter (along with the replacement of the weeping tile). While this method of waterproofing a basement is very effective when done correctly, it is also the most expensive way to waterproof your basement and it is without a doubt the most destructive way to go about it (there are always exceptions of course).

External excavation is, by far, the basement waterproofing method proposed by most waterproofing contractors, and contractors in general. One of the reasons for this is that these waterproofing jobs are a big job and cost many $1000’s, so these jobs are nice to sell. However, the external basement waterproofing method is not necessarily your best option to waterproof your foundation because the cause(s) of your wet basement problems may not necessarily be dealt with, even after you have a perfectly waterproof basement. To see what we mean, follow this hyperlink for our blog post entitled “A Leaky Basement Doesn’t Mean Your Basement is Leaking”.

Here’s an example of a common cause of a leaky basement that probably won’t be fixed by waterproofing your foundation by digging it up. In the image below you will notice a considerable amount of water beneath the basement floor; this water is present because of a high water table. When a high water table is the cause of your wet basement, waterproofing the foundation walls on the exterior will not solve your problem, even by installing brand new weeping tile. How do we know this? Because this picture was taken in a house which is 3 years old!

The Interior Weeping Tile System Method

A second basement waterproofing method, which, while usually less expensive than excavation, but also relatively costly, is an interior weeping tile system. This basement waterproofing method can also be referred to as an internal perimeter drain system, an internal drain tile system, and an internal breakout. The illustration below provides an overview of this type of basement waterproofing system.

This basement waterproofing method should be left to contractors that specialize in waterproofing because the average contractor, while able to excavate around your foundation, wouldn’t usually have much, if any, experience installing this kind of system. The interior perimeter weeping tile waterproofing method requires the use / installation of a sump pump for draining the water that is leaking into your basement.

Connecting an interior weeping tile system to a floor drain is both illegal (against city bylaws) and a bad idea with respect to basement drainage.

Epoxy and Polyurethane Injection

Some foundations in Toronto have been constructed with poured concrete since approximately 1910. Leaks in this foundation type are, by far, the easiest and cheapest to repair. Used mainly to repair a crack in a basement wall, these basement waterproofing methods repair concrete via a pressurized injection of epoxy or polyurethane resins into either foundation cracks or voids. Waterproofing a basement wall is accomplished by filling the voids with resin, thereby eliminating the cracks and voids, therefore preventing basement leaks in the future.

There are a handful of waterproofers that offer another method to repair a basement crack in a poured concrete foundation. This crack repair method is not an actual crack repair; rather, it involves covering the crack with a rubber film and using the gravel beneath your concrete basement floor to drain the water that continues to leak through the foundation wall. While this repair technique usually results in a dry basement when the cause of water in the basement is a leaking crack, this method does have a negative side as well.

A rising water table, particularly after heavy rains and snow melts, sometimes causes wet basements and, in extreme cases, flooded basements. AquaGuard Injection & Waterproofing® does not recommend this specific basement waterproofing method to repair leaking foundation cracks because draining the water from a basement leak beneath the floor can dramatically increase the amount of water that enters your basement from beneath the basement floor due to a rising water table.

Note: At the end of the day, excellent long term basement waterproofing requires the use of the most appropriate basement waterproofing method as well as sound procedures (and their execution), and top quality waterproofing materials. Given the level of expertise, field experience and research required for outstanding basement waterproofing, any basement waterproofing repair should be carried out by competent and professional waterproofing contractors. We think the Better Business Bureau website http://www.bbb.org/canada/ is a great place to shortlist contractors that specialize in waterproofing basements.

List of Available Basement Waterproofing Methods

The link below takes you to a page on our site which contains a detailed listing of all available basement waterproofing methods, and their applications, sorted by foundation type. We have included an indicator of the relative cost for each type of foundation repair as well.

Basement Waterproofing Repair Methods

Click on one of the following hyperlinks for detailed information on the waterproofing methods discussed in this post:

External excavation and waterproofing

Interior weeping tile system installation

Foundation crack repair using epoxy and polyurethane injection