Depending on the intensity of the rainfall approximately every 1000 square feet of roof surface area,1 inch of rainfall can deposit an estimated 600 gallons of water directly next to your home and foundation.
Let’s start with the basics. Chronic water infiltration is a much more common problem than flooding. You do not need to live in a “Flood Zone” to have water in the basement. Most water infiltration issues in homes with basements or crawl spaces come from groundwater issues. If water is directed toward or collects near the home, it will inevitably find its way inside.
The best way to prevent flooding or water damage is to maintain good surface drainage around the exterior of the home. Proper water management starts with the roof and gutters. These are the two biggest contributors to water intrusion.
The grading should slope away from the house to move water away from the foundation. The ground should slope away roughly ½” per foot for at least 10 feet. More of a slope is even better. Make sure that your gutters are clear and free of leaves and debris as they can clog up the downspouts and cause water to overflow at the gutters and prevent the water from getting to the downspouts and away from the foundation. The downspouts should be extended to discharge at least four to six feet away from the foundation.
In 95% of homes, these two factors will keep the lower level dry. Don’t immediately react to a wet basement by calling a waterproofing company; those expensive systems are not always necessary and should only be considered as a last resort. If you have addressed ground water issues first and still have chronic moisture issues, they may be your best option.
If the problems are chronic, homeowners may need to install a drain tile system and sump pump system with a battery backup which will help to divert water away from the foundation of the house.
What to do if I’ve had water in the basement?
The most important thing you can do is to air everything out immediately. Depending on the severity of the water intrusion and the finishes of the basement, this may mean tearing up carpet and padding, cutting out drywall up to a dry level, removing insulation and having everything aired out as soon as possible. Large industrial dehumidifiers, air filtration systems and fans do a great job. Note that it may takes days to air out to become totally dry. Water intrusion like this brings in mold spores. Mold loves moisture. If mold is already present (and it can happen quickly) you will need to have the mold remediated. If you are not comfortable with all that this entails, make sure you get a professional right away. Getting this taken care of with in 48 hours is a must.
Before the storm.
Take a walk around your house before the rainy season in your area and ask yourself these questions.
- Are my gutters secured to the house and clean?
- Do my gutters slope towards the down spouts?
- Are the downspouts secure to the house?
- Do I have extensions on the downspouts or are they depositing water directly at the foundation?
- Does the ground around the foundation slope away?
And don’t forget an under deck drainage system!
If you follow these simple guidelines, in most cases water intrusion can be avoided.
If you are not sure about your house, call Highland Home Inspections to come out and evaluate your property.