Why Do I Have Water in my Basement?

By the time you discover there is a problem, it is not too late but it can certainly dampen your weekend. With the increased instances of rainfall in certain areas, flood management and building on flood plains and other factors, the likelihood of a wet basement is a probability for most home owners. If it hasn’t already happened to you, consider yourself fortunate because whether you own an older home or a newly built one, there is a chance of developing a problem at the foundation of it all.

What can be frustrating though is that there are few to any warning signs before your basement floods. In other words, it is unlikely that you will have any kind of hint or indicator prior to your basement flooding. And that’s why the damage and loss in a basement flood is so significant. As a homeowner you do not expect your basement to flood, and in most instances you have furnishings, audio visual equipment and even storage or keepsakes susceptible to damage. In any wet basement issue there are two strategic plans of attack. First, the homeowner will need to figure out where and how the moisture is entering the home. The second phase is applying the right fix and solution to the problem in order to prevent it from happening again. If you have been confronted with a leaking basement, we’ll help you turn the tide with professional tips that address both the diagnostic and clean up, as well as prevention.


There are a variety of sources of water which can create problems for your home. One of the most frequent sources is the accumulation of a high volume of rainwater in a short period of time. The ground is able to absorb water at a certain rate and over time. When excessive ground water occurs, the saturated soil cannot absorb the water vertically, and runoff is created which can pool around the underground walls of homes and structures. This is why there is a prevalence of basement flooding in the spring, depending on seasonal conditions. When a new home is built, surveyors and contractors are aware of the existence and depth of water tables as well as naturally occurring springs. These sources of water, and the proximity to natural rivers or lakes increases the likelihood of basement flooding. In new construction, effective sump pumps are installed to manage excess water when the level exceeds the natural gravity level of the basement foundation. Once water rises to a level higher than the basement, the sump pump removes and channels the excess away to prevent erosion and leaks. Cold weather can also create situations where homeowner plumbing and even municipal plumbing such as water lines or sewer lines rupture. Flooding can occur when essential pipes are blocked by debris or obstructed or ruptured by roots, plants and other natural sources.


Many homeowners do not understand the construction of a foundation or basement in a home. It is hard to believe that there is a tremendous amount of ground water behind the walls of your basement and under the concrete floor beneath your feet. While there are higher risk seasons for flooding (such as spring runoff) moisture can find its way into any basement if the foundation has not be adequately treated and/or if it has not been treated at all to resist water. You are probably wondering how it is even possible to hide a poorly sealed basement. But the truth is that the sealant is applied to the exterior of the foundation and then covered with soil. It is impossible for a home inspector to be able to assess the quality of the waterproofing on a home, without digging up the exterior walls to inspect it manually. And since excavation costs for an average home start at about $10,000 it is a costly procedure not many home owners are willing to engage in unless they have to. Historically homes have been water proofed using a few standard methods.


For masonry a thick coating of concrete can be applied directly to the wall which adheres and permanently creates a waterproof barrier. The method that the concrete coating is applied is the key, and a thick brush made of heavy, natural fibres creates a ‘swirl’ pattern which is both visually appealing as well as effective at preventing water from running laterally down the surface of the wall which channels it.

For some dwellings the concrete waterproof coating is an economical way of adding another layer of moisture protection but it must be applied directly to clean masonry (unpainted or untreated). The cost is approximately $60 per 100 square feet of treatment.


This type of sealant has been one of the main choices for residential and commercial structures historically, however expertise is required to get the best value and results from the application of a silicate sealant. Where many DIY homeowners go wrong with this method of waterproofing is under application, and they try to economize the budget by applying less of the silicate sealant which leads to an inadequate seal on the masonry.

Silicate sealants work by creating a chemical reaction (CSH) Calcium Silicate Hydrate, which essentially seals every open capillary of the concrete as the composite reacts to the calcium and lime found in the masonry. In order to create that chemical reaction the pores of the surface must be thoroughly saturated with the sealant to protect bricks and mortar against absorption of water and salt, which create erosion.

It is also possible to over-apply a silicate sealant without allowing it to cure properly, and the result creates a fine dust that is easily swept and washed away, offering little protection to the foundation. Two thick coats is generally sufficient for most projects at an average material cost of $50 per 200 square feet.


Acrylic paints are waterproof and they are easy to apply with a brush or a commercial sprayer. They offer moderate protection, and can be applied over other pre-painted surfaces. This method is sometimes used to treat the inside wall of masonry behind the insulation as a second barrier to moisture. It requires a thick application and usually two dried coats to be effective at a cost of approximately $40 per 75 square feet.


Waterproof plastic sheets are sometimes added as a third layer of moisture protection to the interior of basements. New products include recycled waterproof membranes which act like a series of textured vertical channels that protect the concrete wall from water while channeling it down toward the ground and installed gravel and weeping tile. Water and salt run along the hard, non-porous surface and is not given the opportunity to be absorbed into the masonry, which protects it from erosion and damage. While it is possible to undertake waterproofing of your basement, or the installation of essential equipment such as an effective sump pump system, most builders recommend consulting with a certified professional. If excavation is required, the process of waterproofing your basement is a capital investment that is necessary and one that will save the homeowner additional costs and property loss in the future.

A certified professional can help you identify the source, resolve the problem and create systems to prevent a basement flood from happening again. When you consider the cost of replacing damaged flooring, walls, insulation and personal effects, it pays to get it done right.

About Aquamaster Waterproofing

Aquamaster Basement Waterproofing is your full-service plumbing and basement waterproofing company assisting the Greater Toronto Area residents. We offer services such as drain repair, drain cleaning, basement waterproofing, basement underpinning, sump pump installation, and more.

Share the Post: