Water in crawl space: What causes it and how to fix it
If your home has a crawl space, you’ve probably not given it too much thought. Because the spaces are usually between 12 and 36 inches high, they are not livable areas, and their sole purpose is to raise the home off the ground. Oftentimes they are dark and dingy parts of your home – not somewhere you check regularly. However, like basements, they are extremely susceptible to flooding and leaks.
If you do find water in your crawl space, it’s best not to ignore the problem. Although it can be awkward to remove, you should take active and definitive steps to ensure that you remove the water and prevent it from coming back.
This guide will help you diagnose the causes of water in your crawl space and give you tips on how to keep it out.
CAUSES OF WATER IN A CRAWL SPACE
If you do have water in your crawl space, the first step is to perform a diagnostic test to determine where the water is coming from. The majority of times, water comes from one of the following five causes:
POOR GRADING OF THE YARD
If your yard has poor grading (i.e. it is sloped towards your home or is flat) then water will either pool on the surface or run directly towards your home. This will mean that, eventually, the hydrostatic pressure of the water will cause it to force its way inside your home.
If you do find that the grading is poor, solving it can range from just piling up earth nearer your home to create a slope up to more significant regrading involving large machinery.
Aim for a slope of 6-8 inches over the first 6-8 feet away from your home. If this does not do the trick, you may need to bring in larger equipment and/or professionals for more significant regrading of your yard.
If your gutters do not extend far enough away from your home, then it is likely that this is a cause of water in your crawl space. Check your gutters to see if they extend at least six feet (ideally eight) from your home. If they do not, then you’re effectively allowing all the rain from your roof to be poured onto the foundation of your home.
Check your gutters immediately after rain to see how and where they flow. You should also check them regularly to keep them free of debris and blockages.
OVER-WATERING A YARD
As with gutter problems, over-watering your yard will cause the soil around your home to become saturated, which creates pressure on the structure of your foundation, leading to cracks and water seepage through the foundation.
If you have a sprinkler system or use a hose, make sure that you are not saturating the earth. If you can raise water by placing your foot on the ground, then there is too much water in the soil.
BURST WATER LINES
If the first three causes are all homeowner error, a burst water line is somewhat unavoidable – particularly if it is the city’s water main. You can conduct regular inspections of your pipes to see that they are not cracked.
Be particularly vigilant after times of extreme heat and extreme cold (cold in particular causes burst pipes because of the capacity for freezing).
You should also be cognizant that a burst pipe anywhere in your home can lead to water in the crawl space – water can travel down through the structure of your house, so a burst pipe on the top floor may be the root of water in your crawl space.
Subterranean water refers to water that is below the surface of the earth. There are a number of different potential causes of subterranean water, any of which may result in water entering your crawl space through a crack. The most common sources of underground water are:
If you do have water in your crawl space, the temptation may be to ignore it – after all, crawl spaces aren’t exactly usable parts of your home.
However, this would be an extremely bad idea, as water entering your home at all can have major knock-on effects. In fact, spotting water early can end up saving thousands of dollars in long-term repairs.
Water damage in your crawl space has an average removal cost of between $1,200 and $4,500 (usually on the lower end of that spectrum). By contrast, structural or foundation damage can cost $5,000-$7,000.
Given that water, left unchecked, can cause such significant damage, it’s easy to see how action in the short-term is preferable.
HIGHER ENERGY BILLS
Damp air in your crawl space is more expensive to heat up and cool down, making your energy bills higher. Effectively, you will be paying to heat the water lying around in your crawl space, which will suck up valuable energy.
Mold is (along with the long-term cost) perhaps the best reason to address water in your crawl space. Mold thrives in damp, dark, warm environments, meaning your crawl space is an ideal breeding ground. Additionally, mold can very quickly spread throughout your home.
DUST MITES AND PESTS
Like mold, dust mites like humid spaces, meaning a moist crawl space is ideal. Dust mites breed quickly and are extremely difficult to get rid of. Their droppings can also trigger asthma and other allergies.
Once you start to get dust mites, you can very quickly build up an ecosystem in your crawl space, with animals as large as rats and snakes living in there.
A source of water makes the space much more inhabitable for all sorts of pests, from the microscopic to the unsettlingly large.
HOW TO FIX
Now you’ve identified the root of the problem and understood why it’s best to act, it’s time to decide what to do.
If you are in any doubt, then call in a professional. You should also make a call to your insurance company. Depending on the source of the water, and the type of damage it has caused, you may be able to cover some of the cost.
REPAIR FOUNDATION CRACKS
If water has entered your home through cracks in the foundation, then you will absolutely need to get your foundation fixed.
However, if the crack is larger, your cost will rise to between $350 and $1,350.
That’s still preferable to a major structural repair to the foundation, which will cost up to $15,000.
FIX DRAINAGE ISSUES
Because of the problems caused by water in a crawl space, most are fitted with some sort of drainage already. If you have water in your crawl space, the drainage system you have is not working properly.
Check to see if it is clogged or damaged. If not, you may need to install additional drains to help the water flow away from your home. As with the gutters, you should be sure that any drainage system is venting at least six feet away from your home.
INSTALL A SUMP PUMP
Perhaps the most common technique for addressing water in your crawl space is to install a sump pump. The average cost of putting in a sump pump is between $750 and $1,150. A sump pump works by removing all of the water from a sump pit that has accumulated, thereby ensuring that the water table remains lower than the floor of your crawl space.
If you already have a sump pump, you should make sure it is regularly inspected by a professional to make sure it is functioning properly.
Once every three years, have a professional inspect the water pipes in your home. This will identify potentially problematic areas and avoid the need for costly water remediation. The cost for a plumbing inspection is between $150 and $500 (this does not include the cost of any repairs).
The cost of replacing a water pipe is roughly $2-$4.50 per linear foot. Again, the sooner you identify a fault, the smaller the amount of pipe you may need to replace.
Most crawl spaces were specifically designed to keep moisture out of the rest of the home. This can easily lead to an attitude where they are expected to be a little damp.
However, they can quickly cause problems for the rest of the house if:
Fixing a small problem in the crawl space is far cheaper in the short-term than it would be to leave it unchecked. After all, the crawl space shouldn’t be a part of the house you have to think about. Making sure it remains dry is central to that approach.