6 Common Causes of Water Damage in Home

Your house is a complex structure. Inside, there are several mini-systems that must run efficiently to ensure that you and your family are in a conducive and healthy living environment.

When some of these mini-systems, especially those that require water to operate, are not functioning properly, problems are likely to occur.

Causes of Water Damage in Your House

We already know what water damage is. Now, let’s look at the causes of water damage inside your house- both major and minor.

The top 6 most common causes of water damage in your house are:

  1. Issues with the plumbing system, including old plumbing and broken pipes.
  2. Leaks from malfunctioning or faulty household appliances such as water heaters and washing machines.
  3. Accidents involving water- for example, overflowing bathtubs.
  4. Sewer back-up.
  5. Humidity build-up allows water to collect in some areas such as crawl spaces, basements, and attics. This happens over a long time but is very common either way.
  6. Issues with the Heating, ventilating, and air conditioning systems (HVAC) in your home.

Understanding the causes of house water damage is important for two reasons:

  • It helps you know when you are at risk of experiencing water problems even before they happen. Thus, putting you in a good position to minimize chances of its occurrence or just avoid the damages altogether.
  • It enables you to easily identify any water damages to your house, handling them in good time.

Undoubtedly, time is a crucial factor in handling water damage.

Why? Because the longer the damages remain unattended, the worse they become and the more expensive it gets to repair them.

Therefore, paying proper attention to this article will put you ahead of the curve when it comes to safeguarding your home environment from any water damage issues.

To begin with, let’s discuss the causes of water damage inside your household- including those that are not very common, but you should be aware of.

We will also look at a few steps to prevent water damages.

Hopefully, this article will save you a lot of time and money from dealing with the aftermath. At the same time, helping you create to maintain a healthy home environment that will support your health and overall wellness in life.

Internal & External Causes of House Water Damage

In general, the causes of water damage to your house can be divided into two broad categories based on their place of origin. Internal and external.

The internal causes of house water damage come from inside your household. Malfunctioning household appliances fit perfectly into this category. On the other hand, the external causes of house water damage originate from the outside of your house—a good example of this flood.

It is important to note that: even though external causes originate from outside your house, the resultant damages are felt and seen inside your home.

There are several sub-categories within these 2 broad categories of water damage, as shown in the table below.

Internal causes of water damageExternal causes of water damage
Issues with plumbing system.Natural disasters/ Weather-related causes such as floods.
Malfunctioning appliances around the house.Structural damage to your house- those that result from how your house is structured on the outside example flat roofs and gutters.
Accidents involving water inside your home.
Sewer back-up.
Water collected in basements, attics and crawl-spaces.
Issues with the HVAC systems.

Internal Causes of House Water Damage

As explained above, these causes of water damage come from inside your house.

Therefore, to avoid water damages to your house, you must pay close attention to this section. Because this is where most of your control, if not all of it, lies. If the source/cause of water damage comes from inside your house, you can easily identify it and stop it.

There are 6 sub-categories under this broad category. And, all the top 6 most common causes of water damage mentioned above fall under this broad category.

1# Issues with the plumbing system

This is the number one reason you are likely to face water damage in your home.

Over time, your plumbing system experiences wear and tear, increasing its susceptibility to clogs, stoppages, and breaks. Temperature fluctuations can also lead to broken pipes creating major issues with your plumbing system.

As a result, water leaks from pipes in your bathroom, kitchen, and other areas of your home.

Water leaks from damaged or broken pipes often result in severe water damage inside your house since they can easily go unnoticed.

Why? Because the signs of the damage caused by water leaks inside your household may take too long to show.

How do you identify issues with your plumbing system early enough? There are 3 ways to do this;

  • From your taps– check if the water pressure coming from your taps seems too low or if the water is discolored and appears yellowish or brown.
  • Monitor your water bill– a sudden spike in your billing may indicate the presence of a leak in your plumbing system. Addressing the issue is important before additional damages occur to your flooring, landscaping, foundation, and other parts of your home.
  • Using leak detection systems – There are 2 major types of leak detection systems you can use to spot leaking pipes in your home. Passive and active leak detection systems.

The passive leak detection systems are relatively cheap and easy to use. They sound an alarm whenever they sense the onset of a leak.

On the other hand, the active ones are a bit more expensive. However, in addition to sounding an alarm when there is a leak, they act to contain and stop it on its own. This saves money and the energy needed to respond to the leak.

Prevention and control:

  • If you spot or suspect a leak in your plumbing system, first, turn off your house’s main water supply valve to contain the leak. This will minimize the damage and buy you enough time to locate the leak and deal with it.
  • Perform regular visual inspections to check for any leakages in different areas of your home where pipes are located. This includes the area under your kitchen sink, in your bathroom, as well as your toilet.
  • Pipes located in your basement and at the exterior of your house are prone to very low temperatures hence freezing, especially during the winter months. Ensure that they are all well insulated before the winter months set in.

2# Malfunctioning or faulty appliances around your house

All appliances that use gaskets, filters, tubes, or pipes to operate are potential sources of water damage in your house.

Due to aging, the pipes of these appliances start to rust, crack and their hoses may weaken, causing leakage that leads to extensive water damages in your house.

Although all appliances can cause leakage and damage to your house, you should watch your washing machines, hot water tanks, and dishwashers.

Why? Because the 3 are known to cause water damage in your house most frequently.

Prevention and control:

  • Inspect and maintain your appliances regularly. If you notice any signs of moisture, rust, bulges, or cracks on any of your appliances, take the necessary steps to repair them to avoid further damages.
  • Replace your washing machine’s old water supply lines with better ones. You may use the ones made of braided stainless steel instead of rubber because they last longer and do not burst easily when subjected to constant pressure.
  • Re-caulk and re-seal your bathtubs and showers from time to time to minimize the occurrence of water leakages in your house.

3# Accidents involving water in your house

When you leave taps open or fail to close them properly because you are in a hurry to leave the house for one reason or another, you create a potential source of water damage.

Overflowing bathtubs and sinks are a common cause of property loss due to water damage in your house.

Water overflows can seep into any part of your home and cause serious damages that are expensive to repair.

Prevention and control:

  • Ensure all taps are closed properly- at all times.
  • Turn the water to the house off if you will be away for more than 24 hours. This will ensure that you prevent any extensive water damage that may occur due to leaks springing up in your absence.

4# Sewer back-up

Sewer lines may get backed up due to heavy rainfall or blockage.

Often, tree roots also invade and clog-up drain lines causing a blockage. As a result, dangerous contaminants spread very fast, creating an unhealthy environment for you and your loved ones.

It is important to note that water from sewers is considered black water, which is highly contaminated and harmful to your health.

As noted before, water damage to your house, resulting from sewer back-up, falls under category 3 water damage. And, since backed-up sewers are a health hazard, the damages they cause are best handled by certified professionals.

5# Water collects in the basements, crawl spaces, and attics

Humidity build-up in areas that are prone to collect water over time. Such areas include basements, attics, and crawl spaces. Humidity build-up takes place after some time because of aging and hydrostatic pressure.

Water collects in the basements, crawl spaces, and attics, leading to overall structural damage from severe mold growth and rotting.

Prevention and control:

  • Install a dehumidifier. It will help reduce and maintain humidity levels in these areas, hence preventing its build-up.

However, in case of water has already been collected in large amounts, you should apply a different process that involves proper water removal.

Consider contacting home inspectors to get an accurate assessment of the amount of water and extent of damage that has taken place.

Once you have received the home inspector’s report, then, and only then, should you contact a water removal/ waterproofing expert to help with the water damage clean-up.

Also, ensure you get more than one quote, preferably 3, from the water removal expert for comparison purposes.

6# Issues with the HVAC system

This is the Heating, ventilating & air-conditioning system in your home. It is installed inside your house and can hold large amounts of water to be directed outside.

The air conditioner pulls humidity from the air and condenses it into moisture. Then, it (the AC) directs the water into an overflow pan to the outside of the house via the condensate line.

If the overflow pan or the condensate line is damaged and not working properly, moisture builds up within the AC. Over time, the moisture soaks up your ceiling, ruining your drywall as well as flooring.

To add, the moisture can mix with mold spores within the AC’s ducts, promoting mold growth.

Prevention and control:

  • Ensure that you regularly service your HVAC system– at least once annually. This will help you notice any potential damages likely to occur on the system in good time. And you can then apply proper mitigation measures.

External Causes of House Water Damage

The external causes of water damage originate from the outside of your house. But, their damaging effects are seen and felt inside your home.

Most, if not all of them, are weather-related. And, even though you might have very little to no control over these causes, you can control how ready and prepared you are for them.

How? By applying the necessary preventative measures regularly to minimize the effects of such damages if they occur.

Sub-categories of External Causes of Water Damage

1# Natural Disasters

Natural disasters are part and parcel of our daily lives. Rivers overflow, hurricanes, and flash floods strike from time to time. Such disasters cause destructive floods that can lead to water damages, commonly referred to as flood damage in your house.

Due to the unpredictability of natural disasters, damages from floodwaters to your household are extensive.

I mean, if hurricanes can cause entire cities to flood- yes, the whole city. Can you imagine the water damage that takes place to the inside of your home?

Natural disasters cause massive property loss. They might destroy your home to the point it becomes inhabitable or unusable until major repairs are done.

The high level of destruction by natural disasters renders flood water damage repairs very expensive. In fact, if you are not careful, you might end up spending a good chunk of your savings handling the repairs.

Pay prompt attention to such disasters by contacting water removal experts as soon as possible afterward. It will help reduce the time for severe water damage to occur. This will make the work of the water removal experts a lot easier and save you a lot of money too.

Prevention and control:

  • Install doors and windows that are highly resistant to heavy rains and other natural disasters. Ensure that you apply all the precautionary measures outlined by the local regulations.
  • Store your sensitive electronic equipment and files at high levels inside your house. This is something you can do ahead of time to keep the overall water damage to your house minimal should any water-related natural disaster occur.
  • Consider carrying out a risk assessment to determine the level of risk of flood damage that your home is in. You might find that you live in a moderate to high-risk area. Meaning, the area you live in is prone to flooding, consider purchasing flood insurance.

Water damages due to the external causes explained above can harm your health. It is, therefore, important that you seek professional help as soon as they occur.

2# Structural damage

Structural damage to your house’s roof, gutters, and entire foundation is a common external cause of water damage.

Despite being one of the top causes of water leaks that damage your house’s interior, it is rarely discussed.


Normally, roofs have a slight gradient/slope that enables them to direct rainwater into your gutters. Over time, the slight slope may fill up with debris, including leaves and even branches.

When this happens, the roof becomes flat, efficiently preventing rainwater from being directed into your gutters. As a result, rainwater collects on top of the blocked roof instead of running off it through the gutters.

Standing rainwater on top of your roof causes extensive damages inside your house.


  • The weight of the debris and standing water can lead to cracks on your roof. Then the cracks will allow water to leak into your ceiling, causing widespread damages to your house.
  • Mold starts to grow on the roof itself and the ceiling of your home aggressively.
  • Cold weather also leads to the formation of “ice dams” on your roof. In this case, the roof works well. Water may collect as a small pool on it as usual. But, before it could run off to the ground, the edges of the pool of water freeze creating ice-dams. Standing water from ice dams causes extensive water damages in your house, especially on the ceiling.


The gutter system serves to direct water away from your roof. And from the entire building through the edges.

Water collects, and a dam forms on the gutters when this system is not working properly. With time, the water overflows over the gutter’s edges and begins running down the sides of your house. Leading to water damage to the walls of your house.

You can easily notice this form of water damage by looking at your walls. Is the paint peeling off? Can you spot any dirty water marks from rainwater that has spilled over from your gutters?

Water damage to your house’s walls also happens when your gutter system is faulty. Suppose your gutter has a hole or crack, water leaks down your building’s side even if there is no heavy rain. Either way, you are likely to face serious water damage to the walls of your house.

Additionally, your walls might remain wet constantly and for a long time, causing the damage to spread.

In the worst possible case, water that runs down the sides of your gutters might start collecting at the base. At this point, standing water that is building up causes more severe damages due to basement leaks and mold growth.

Prevention and control:

  • Practice proper regular and seasonal home maintenance to prevent the build-up of debris and other materials on the roofs and gutters. This way, your risk of experiencing water damage due to an ineffective gutter system is reduced. And, you can always carry out any repairs should you notice your gutter system is faulty, in good time.

Other common causes of water damage inside and outside your house include:

  • The toilet runs and eventually drips, ruining your walls and floors.
  • Your garbage disposal can flood cabinets with dirty water mixed with food garbage. Always check for any leaks on your garbage disposal to prevent this from time to time.
  • The sump pump, which directs water away from your housekeeping your crawlspace or basement dry, can stop pumping. Water begins to build up when this happens, leading to crawlspace/basement flooding.
  • Drains can stop draining, allowing water to collect at different parts of your home. A blocked floor drain, for example, results in your basement filling up with water. You can open up clogged drains easily using air blasters, plumbing snakes, or plungers.
  • Fire sprinkler systems can freeze and burst during the winter months if you do not perform regular winter maintenance. Proper sprinkler maintenance routines, especially during cold weather, prevent the system from bursting. And helps you avoid water damage in your house.

Final Thoughts

Water damage in your house is a common occurrence. And, by now, you can clearly tell that home water damage is something you are likely to face not once but severally. You will need the services of a certified water damage restoration expert at some point since you cannot eliminate all the risk of experiencing water damage.

DIY solutions cannot be applied to all forms or types of water damage.

Remember: you always have a choice to make all the necessary preventive measures in good time. This will reduce your risk/ chances of facing water damage inside your home. And help you respond appropriately should you notice any potential sources of damage.

Now that you have understood what causes water damage in your house, how can you identify the damage? I mean, do you know what some of the early signs of water damage to your house? This is very important. Because you will know which signs or changes to be on the lookout for. As a result, you will be in a good position to contain any water damage in your household.

Mas Broto

Written by: Mas Broto

Mas Broto is a small business owner with 30 years experience in the real estate industry. He is the founder and editor of theDailyThrive.net, the most comprehensive free home improvement website on the planet!