Kansas City sees an average annual snowfall of 13 inches, St. Louis and Springfield 17 inches, and Joplin 12 inches. While that may not seem like much, if it all comes quickly or if it builds up over time during a cold winter, it can cause serious flooding in your basement or crawl space.
Snowfall and Water Content
Snow can look beautiful at first, covering everything with a fine white powder. Of course, that snow contains water. Just how much depends on the water content.
NOAA states that 13 inches of snow equals one inch of rain. But it goes on to say that two inches of sleet and up to 50 inches of very dry, powdery snow can equal that same one inch of rain.
One inch of rain collected over a 2,800-square-foot roof adds up to 1,743 gallons of water—more snow, more water. Plus, there are the effects of thawing and freezing, building up ice on your roof and around your home.
Snowmelt and Ice on the Roof
During the day, with a bit of sunlight and warmer temperatures, the snow will start to melt. Melting can also be increased if there is insufficient insulation in the attic. The resulting water should run off the roof through the gutters and downspouts.
This is followed by freezing at night forming ice on the roof, which can build up ice dams, collecting more water on the roof. Likewise, the downspouts and gutters can freeze, causing still more buildup on the roof. This problem often manifests as icicles hanging off the edge of the roof.
Snow on the Lawn
With frozen gutters and downspouts, the water has nowhere to run but off the edge of your roof directly onto the soil around the foundation.
The snow has also been collecting on the lawn and around the foundation. That could include drifting snow as well as snow removed from your driveway and walkways. Given that, any snowmelt has already saturated the soil.
Plus, if the walls of the basement or crawl space are not sufficiently insulated, the snow has been melting even before outdoor temperatures rise.
Water Pressure on the Foundation
Some water will be able to run off on the surface based on proper landscape grading. Unfortunately, much of the water will also form an underground flow headed directly to the basement or crawl space.
This is due to the clay bowl effect where the soil around the foundation has a different drainage factor than the rest of the soil around your home. When excavating during construction and then backfilling around the foundation, the replacement soil allows more drainage than the surrounding undisturbed soil. The underground water naturally moves toward the foundation.
The resulting hydrostatic pressure can force its way through any cracks. It can even expand those cracks through freezing and expanding. The end result is flooding.
There are a number of ways you can prepare your home for snowmelt and the resulting water runoff.
- Repair Gutters and Downspouts. Spring is a good time to repair any winter storm damage and prepare for summer storms. Once winter is here, it’s almost impossible to make these repairs after ice has formed.
- Clean Out Gutters and Downspouts. Fall is a great time to not only clear all the leaves from your lawn but also clear all the gutters and downspouts so water can flow freely off the roof.
- Improve Landscape Grading. Whether it’s snowmelt or rain, proper landscape grading can facilitate water runoff away from your home. Add downspout extensions or have these lines placed in the ground to route the water away from the foundation.
- Remove Excess Rooftop Snow. Use a roof rake to pull down snow from your roof. This not only eases the weight buildup but helps prevent ice dams and water buildup that can overwhelm your gutters and downspouts.
- Don’t Pile Snow Near Your Home. When shoveling or blowing snow off walkways and the driveway, move it away from your foundation rather than piling it up there. You should also remove excess snow to a distance of four to six feet away from the foundation.
- Add Attic and Foundation Insulation. Heat escaping through the roof or through foundation walls can lead to snowmelt and water everywhere you don’t want it. Additional insulation can help prevent this and save on heating costs.
- Waterproof the Basement or Crawl Space. Fix cracks and install an interior drainage system. A sump pump system can remove any water that does make it into your basement or crawl space.
- Sump Pump Maintenance. Check the drain lines along with the battery backup for a sump pump. It’s also critical to monitor for possible freezing drain lines that can cause burned-out pumps.
You can rely on the professionals at Foundation Recovery Systems to help identify any potential problems through a free inspection and repair quote.