The average annual snowfall in Cleveland is 68 inches, thanks in large part to lake effect snow courtesy of Lake Erie. All that snow can be beautiful during those first few days of winter weather, but it gets enormously tiresome as the weeks and months go by and the snow piles up.
It’s when the temperatures start to warm and the snow starts to melt that we should be encouraged with signs of the coming spring. However, that’s when basements and crawl spaces can start leaking and even flooding.
How Much Water Could There Be?
The general rule of thumb is that 13 inches of snow equals one inch of rain. The challenge is that rain runs off roofs but snow builds up, essentially stacking water higher and higher not only on your roof, but also your lawn and your driveway.
To put this all in perspective, if we consider a 2,800-square-foot roof with 13 inches of snow, that amounts to 1,743 gallons of water. With heavy, wet snow, it could amount to as much as 5,000 gallons; with dry powder snow, perhaps only 1,000 gallons.
Drifts and Stacks of Snow
It’s not only the roof that is collecting snow. Snow drifts can build up around your home, and there is also snow on sidewalks and driveways. With shoveling and plowing, that snow is further stacked up on your lawn. All this brings even more water into play.
As the snow melts, water starts moving off the roof and into gutters, through the downspouts and any extensions. Then it joins the snow on the ground that has already saturated the soil around your foundation.
Ideally, the water on the ground is moving away from your home’s foundation due to the landscape grading. However, even with superb grading, since the soil is saturated, an underground water flow will develop moving toward your basement or crawl space. This is caused by the clay bowl effect.
Clay Bowl Effect
During foundation construction the soil is excavated, the basement or crawl space poured, and the soil backfilled around the foundation. This backfilled soil is looser and far more porous than the undisturbed surrounding soil. This provides a ready path for underground water to collect in the “bowl” around the foundation.
As the water builds up, it creates hydrostatic pressure on the basement or crawl space. It can then readily find any cracks or openings. Plus, it can create new cracks or expand old cracks with freezing conditions. This inevitably results in leaks that can lead to basement or crawl space flooding.
Freezing and Thawing — Ice and Ice Dams
Of course, it’s not a simple matter of snow followed by thawing. Instead, the snow builds up over time, along with melting during daytime sunlight and warming temperatures. Plus, there may be heat escaping through the attic, causing further melting. That’s followed by freezing temperatures at night.
All this adds up to ice forming on the roof, particularly on the edges and in the gutters and downspouts. This usually shows up as picturesque icicles that are a warning sign of ice dam formation. As the ice builds up with thawing and freezing, it stops the water flow from building up ever more water on the roof.
As temperatures increase, the snowmelt builds up enough to flow over the ice dams and run directly past the frozen gutters onto the ground below. That makes for a great deal of water hitting the home’s foundation.
How to Prepare for Snowmelt
You can readily see that snowmelt can cause a great deal of damage to your home’s foundation. Preparation is the key to prevent this damage. Here’s our list of tips.
- Clear the Snow. Keep snow from building up around your foundation to at least four to six feet. As snow builds up on your roof, use a roof rake to remove it. All this will reduce the water buildup around the basement or crawl space.
- Install and Maintain Gutters and Downspouts. Install correctly sized gutters and downspouts to handle the expected rain and snowmelt. Keep them clear of leaves and obstructions and repair any damage.
- Consider Landscape Grading. Once the water is on the ground, it needs to move away from the foundation. Landscape grading provides the slope necessary to keep the water moving. Also, use downspout extensions to move the water from the roof well away from the foundation.
- Install Attic and Foundation Insulation. Thawing from heat escaping from the attic and around the foundation can lead to foundation leaks and flooding. Add attic insulation and ensure the foundation is adequately insulated to prevent heat escape. This can also save on energy costs.
- Waterproof Your Foundation. Install an interior drainage system to collect and remove leaks before they can cause damage and flooding.
- Practice Sump Pump System Maintenance. With any existing drainage system, make sure the sump pump is working and that the drain lines are clear. Watch throughout the winter for freezing drain lines that could lead to serious problems.
For professional advice on preparing your home for snowmelt, from waterproofing your basement or crawl space to maintaining your drainage system, contact your local foundation experts at Ohio Basement Systems for a free inspection and repair estimate.