basement waterproofing

Complete Guide To Basement Waterproofing For Residential And Commercial Building

What Is Basement Waterproofing?

The techniques and materials utilized to prevent water from penetrating the structure’s basement are referred to as “basement waterproofing.” Basements are particularly prone to the development of moisture and dampness. Inadequate soil and drainage systems, gutters that were installed and maintained improperly, an unfavorable slope, hydrostatic pressure, condensation, and other factors are the main causes of this. The purpose of installing basement waterproofing is to prevent all of these.

Residential Basement Waterproofing

No homeowner wants a wet basement. What seems to be a mere trickle or tiny puddle is an indication of a much bigger issue. Your basement’s moisture could cause several expensive and time-consuming issues. Water in your basement is a severe issue since it can cause structural damage or dangerous mold. So, you need a reputable residential waterproofing firm in North Sydney.

Commercial Basement Waterproofing

If your commercial property doesn’t have adequate waterproofing, you, as a business owner or property manager, could be in danger of losing thousands of dollars in damages. Your office building, warehouse, apartment complex, or other commercial property may quickly experience catastrophic structural issues as a result of water damage.   

Remember that the foundations of commercial structures are very different from those of residential ones. Always hire a Sydney waterproofing contractor who is knowledgeable about these underlying concepts so they can give you long-term solutions.

Understanding the difference between interior and exterior commercial waterproofing is also useful. We have you covered: Exterior vs Interior Commercial Waterproofing: Ultimate Guide 2022.

Types Of Basement Waterproofing

Wall Cracks Or Hole Injections

Poured foundation cracks can be fixed by injecting epoxy or polyurethane foam at low pressure. Which is more effective for filling gaps in concrete, epoxy or polyurethane foam?

Epoxies for crack injection come in a variety of viscosities to accommodate cracks of various lengths. Any viscosity necessary to inject a specific fracture at pressures lower than 40 psi is advised. The more extensive the crack, the thicker the material must be.

Epoxies’ incredible compressive strength, which at 12,000 psi or higher surpasses that of the majority of concrete, is their key benefit. Epoxies are the only option for cracks that need structural repair because of this. Epoxies heal very slowly and typically take hours to solidify. As a result, the epoxy has more time to seep into even the smallest cracks, which can be advantageous.

Polyurethane foams should be used if material escaping out the back of a fracture is a concern. These elastomeric, quick-setting foams work well in applications where just crack sealing, not structural restoration, is required. Also, minutes after injection, they start to foam and solidify. This lessens the possibility of material leaking out of an injected fracture while it is still liquid, and even if it does, the foam will fill the space.

Sump Pumps

A sump pump is a piece of machinery that moves water from your basement to the exterior of your home. A sump is a naturally occurring pit that often takes the shape of a hole dug beneath your basement floor. This trench in the shape of a basin houses the sump pump. The pump is equipped with valves that detect rising water pressure or level. When the water level in the basement rises too high, sump pumps automatically drain the extra water using a discharge pipe and away from your house. A specified drainage area is connected to the sump pump by a line known as an effluent.    

A sump pump is a tool that keeps an eye on rising water levels and pressure to make sure they don’t get out of hand. These pumps use a switch to determine how much water is in the basin. Rising water levels that trip the switch cause the pump to start pumping water into a discharge pipe and away from the house’s foundation. 

Interior French Drain Systems

Interior French Drains are trenches that allow water to flow through them and into a sump pump basin. The trench is lined with gravel and covered with perforated pipe, allowing water to flow freely inside before emptying safely away from your house. A French drain’s function is to direct water away from your house to lessen flooding and the harm it causes, such as weakened foundations.


One of the pieces of the puzzle that is frequently overlooked is the importance of a dehumidification system. Low humidity reduces the possibility of mold growth, pest infestation, and property damage. Properly conditioning lower-level air frequently improves the living environment throughout the entire structure. Almost all basements could use a dehumidification system. Even if the floor and walls seem dry, the house may be getting a lot of moisture.

When Should You Waterproof Your Basement?

Basement waterproofing is best done during new construction. However, because basements are prone to moisture, multiple waterproofing techniques may be needed, depending on the underlying source of the issue. If you are in Cronulla, you must get in touch with a reputable waterproofing company to help you determine the root of your basement’s moisture issue, choose the best solution to address it, and stop it from happening again.

What Part Of The Basement Should Be Waterproofed?

When waterproofing your basement, drainage should be a top priority because inadequate drainage can result in flooding during bad weather or catastrophic issues if there are unseen gaps in the walls or window insulation.

Usually, the section of your basement that you can take care of on your own is the interior. This entails looking for cracks or leaks in your basement as well as examining window seals, the plumbing, and even the foundation for water leaks.

While you can fix a lot of leakage issues on the inside of your basement, the majority of waterproofing issues are on the exterior. Be sure to look out for outside problems, which are frequently the source of many basement waterproofing problems.

Signs That You Should Waterproof Your Basement

No matter how difficult it is to find them, stopping them in their tracks will stop them from significantly disrupting your home. Watch out for these warning signs:

 1. Finding water in your basement is the most obvious clue that you need to waterproof it. Even if you only notice a few wet spots on the walls or puddles on the floor when cleaning out your basement, the seepage could worsen and cause significant damage if left unattended.

 2. Excessive dampness is a significant contributor to the paint on your basement walls flaking. This is because the basement waterproofing paint’s adherence is compromised on wet walls. The paint on the basement walls ultimately starts to peel off as a result of this.

 3. When water evaporates and other minerals are left behind, the walls and floors of a concrete basement can develop white, chalky stains. Despite its catchy name, efflorescence may be a sign that your basement’s walls or floor are being exposed to excessive moisture. These white, chalky streaks are a clear sign of water damage.

 4. The majority of basement cracks start as minute, hairline breaches that grow over time as a result of hydrostatic pressure. For this reason, don’t hesitate to get in touch with a reputable Sydney waterproofing basement firm as soon as you see cracks, no matter how little.

 5. When water seeps through the holes in your foundation, there is a greater chance that mold will develop in your basement. Mold stains might be seen on the basement’s walls, ceiling, carpeting, furniture, and other goods that are kept there.

Why Should I Waterproof My Basement?

Get Rid Of Insects

Like us, insects need to drink. They have the ideal approach to obtaining water thanks to the humid climate typical in basements. One benefit of waterproofing your basement for pest control is that small cracks in the foundation and walls are sealed, preventing pests and insects from ever getting into the house.

Exterminate Termites

You might be surprised to find that waterproofing your basement can significantly reduce the chance of termites invading your home. Two things are necessary for termites to begin an infestation. They require both an entry point to enter the substance and a humid atmosphere since they demand water. The simultaneous application of waterproofing can satisfy both of these.

Powderpost Beetles

After termites, powderpost beetles are the second most destructive bug to wood in homes and furnishings. Small, rounded holes will be left in the wood where the adult insects chewed their way out of the wood. So how can you prevent them? Reduce the amount of moisture in the surroundings first. This can be solved by waterproofing.

Prevent Mold

Mold can only grow in an environment that is moist. As a result, regions with a lot of water and moisture tend to have a lot of mold growth. Mold can develop and spread as long as there is moisture. As a result, mold development is more likely to occur in basements containing dampness. Your home’s basement won’t experience as much moisture intrusion if you waterproof it. 

Foundation Damage

Your foundation and/or basement may suffer damage if there is dampness present. The dampness may cause cracks and/or bowing in the walls. Bowing walls should be taken seriously because they are unstable and could even collapse. If cracks appear, additional water and moisture may contact your property and worsen its structural problems. You can prevent the structure of your property from bowing and cracking by waterproofing basement walls from the inside.

Prevent Excess Water

Waterproofing your basement will prevent water from entering your home and reduce the quantity of water that can leak in. Less moisture will now come into touch with your basement as a result. The basement will also be less likely to flood as a result of rain and other external water sources.

Leaking During Rain

In the rainy season, allowing even a minor leak in your basement can have major consequences for your entire home, not just the basement. Mold development, efflorescence, mildew, rusting appliances, and other problems may result from moisture levels that are even slightly out of equilibrium. It’s safe to state that you need to address the problem of rainwater entering your basement.

Water Stains

Water stains are a plain visual warning that water is entering your basement, even if you cannot physically see the water. If you notice water stains on your flooring, your foundation is likely leaking water, and if it has in the past, it will do so again. It is vital to check for stains if you recently moved into a new house. 

Structural Deterioration

The buildup of moisture might eventually cause your walls to become weak and decay. They might eventually start to give way. It would be terrible if your house’s foundation were to collapse since it would put the entire structure in danger.

Causes Of A Wet Basement

Poorly Graded Soil

If the ground around a foundation is flat or slopes toward the house, water is diverted into the basement. The soil near the house is frequently backfilled improperly, which causes it to settle over time. This is particularly true beneath stoops, where water can gather close to the basement wall. Always grade the soil and/or lawn adjacent to your home to prevent surface runoff from moving in the direction of or close to it or the basement wall.

Missing Or Improperly Draining Gutters And Downspouts

Another frequent reason for moist basements is that the home’s downspouts channel roof runoff underground and close to the exterior of the basement wall. As a result, any roof runoff is channeled to an area along the outer wall of the basement. The extra water can and frequently will find a way through the basement wall into your basement over the hours to days it takes for the soil to absorb it away from the basement wall.

Poorly Designed Window Wells

Window well drainage issues result in water leaks into the basement when a window well is not installed, is not the right size, or if the window well drain is clogged. If the water level gets high enough, it may either spill into your basement via the window itself or between the window frame and the top of the wall.

Poorly Installed Window Well Covers

How firmly a window well is attached to the exterior wall surrounding the window determines much of its effectiveness. Soil and water will inevitably seep in through the holes that have been made if it ever becomes separated in any manner. When the house settles as the earth beneath it shifts, a window well that was inadequately built is likely to detach from the wall. 

Ineffective Drain Tile

A home’s drain tile collects water near the basement foundation and sends it in one of two directions. The water will be routed to a sump pump in your basement if your house is not on a slope, where it will be pumped away from the foundation. It’s crucial to take into account a professional basement waterproofing system to make up for the lack of an inefficient sump pump and drain tile.

Blocked French Drains

French drains are underground drainage systems that, if not regularly maintained, can become clogged with debris or tree roots. Hydrostatic pressure may build up in a clogged French drain and lead to issues. The drain pipes may become blocked by mud and debris, rendering them ineffective. 

Sump Pump Not Draining

An obstruction in the discharge line, such as a frozen pipe, is one of the main causes of sump pump issues. If the discharge pipe, which connects the sump pit to the outside area, becomes clogged, the entire system will fail, causing water to build up in your basement.

Water Up Through The Sump

Increased water cannot be drained from the basement by a sump pump that is broken or not operating properly. Your sump pump can be fixed or replaced if it has to be replaced with the aid of internal basement waterproofing in Australia.

Structural Cracks

You can be sure that if your foundation has cracks, water will discover them and seep into your basement. In other cases, the water may even be to blame for the fractures. The foundation walls may be able to move if the floor joists are not securely fastened to them, which will then cause cracks to appear. Due to the soil’s poor drainage, water can potentially develop cracks in the foundation as well.

Which Is Better, Interior Or Exterior Water Drainage?

French drains, both interior, and exterior offer your basement a strong defense against floods and water damage. However, constructing interior drains can be preferable due to the expense and difficulties of installing and maintaining an outside drain on an existing house. To choose the appropriate drainage system for your property, always speak with a basement waterproofing specialist.

How much does it cost to waterproof a basement?

The prices provided by online calculators and estimations range from $1,920 to $6,493 on average for basement waterproofing costs in Sydney.

The cost per square foot ranges from $3 to $10 on average.

Minor repairs can be made for as little as $600, while more complicated and involved waterproofing jobs can cost some properties as much as $10,000.

How Do You Calculate Your Basement Waterproofing Cost?

When determining how much it would cost to waterproof your basement, there are several different factors to take into account. This is because the final cost will vary depending on how big your basement is, the nature of the underlying problem, and the necessary repairs.

Costs For Additional Services

Mold Treatment

Mold eradication often costs $250 to $3,000 in Australia. Mold removal costs may increase depending on the size, degree of contamination, and cost of the mold examination. The average price for expert mold removal is $60 to $110 per hour or $45 to $90 per square meter.

Basement Encapsulation

The typical cost of encapsulating a crawl space is estimated by cost calculators to be around $7,500. The price might range from $5,000 to $30,000 at its lowest point. The price is influenced by many variables, including the size, state, and materials of your crawl space.

How GJK Waterproofing Services Can Help Residential And Commercial Buildings in Sydney With Basement Waterproofing?

For residences, multi-story structures, patios, roads, decks, greenhouses, garages, basements, and other concrete surfaces, GJK Waterproofing Services offers structural basement waterproofing.

The foundation walls will be permanently dried thanks to GJK Waterproofing Services’ innovative waterproofing technology, which also solves any issues brought on by water.

GJK Waterproofing Services is the greatest option for your basement waterproofing needs for far too many reasons to list here. We provide a range of services that will guard your house or building from water damage and the growth of mold.

GJK Waterproofing Services has been in operation for over 25 years and focuses on providing basement waterproofing services in Australia.

If you’re unsure of the best waterproofing materials to use on your property, consider the following GJK Waterproofing Services experts’ advice: What is the Best Waterproofing Material, According to Experts?


Can You Waterproof A Basement From The Inside?

Yes, a basement can be waterproofed from the inside. To begin with, you must ascertain the source of the wetness. Determine whether the outside source or the moisture from condensation on your basement’s walls and windows is causing water to pool after a rainstorm.

Is It Better To Waterproof Basement From The Inside Or Outside?

Waterproofing on the interior and outside both has benefits and drawbacks. Interior basement waterproofing cannot prevent water from entering your basement in the first place; rather, it can only be utilized to eliminate water that has already gathered there. The cost of exterior basement waterproofing can be high, but it protects your home’s foundation and prevents water from entering your house or basement.

What If Water Is Coming Through A Crack In The Floor?

The chance of seepage is greater when the area around the foundation is saturated, especially if the problem isn’t rectified. Utilizing a drainage system close to the foundation is a very successful method of problem mitigation.

The use of a French drain gives a technique to divert some of the water gathered against the exterior wall to a drainage basin situated below, even though it won’t completely address the issue.

What If Water Is Coming Through A Crack In The Wall?

You must choose a reputable foundation crack repair business if your basement wall is cracked and dripping water. If not, the cracks can widen and keep letting water into your basement. This may result in higher humidity, the growth of mold, water damage, and other problems.

What Role Do Sump Pumps Play In A Drainage System?

A sump pump is a piece of machinery that moves water from your basement to the exterior of your home. A sump is a naturally occurring pit that often takes the shape of a hole dug beneath your basement floor. This trench in the shape of a basin houses the sump pump. The pump has valves that can detect rising water pressure or level. When the water level in the basement rises too high, sump pumps automatically drain extra water utilizing a discharge pipe and away from your house. A specified drainage area is connected to the sump pump by a line known as an effluent.

How Long Does Waterproofing Last In A Basement?

The quantity of waterproofing material employed, the environment, and the extent of the initial damage are some of the variables that affect how long waterproofing lasts. There is no specific time due to the variety of components, although the majority of professionals will provide a warranty for ten years or more. Is basement waterproofing worth it? You must be proactive by waterproofing your property if you don’t want to lose your belongings and spend a lot of money on repairs.