The annual average snowfall in eastern Colorado ranges from 88 inches in Boulder to 53 inches in Denver to 25 inches in Sterling. We know snow.
Those first snowfalls can add a wonderful white coating to everything in sight. After a month or two, perhaps with a blizzard mixed in, they are not so beautiful as they are overwhelming. Plus, those piles of snow and ice beside your driveway or collecting on your roof represent a great deal of water.
Snow and Water
The rule of thumb is that 13 inches of snow equals one inch of rain. On a 2,800-square-foot roof, that adds up to 1,743 gallons of water. Of course, that’s for an average snowfall. Powdery snow can amount to a mere 1,000 gallons, while heavy, wet snow can be as much as 5,000 gallons.
Snow on the Roof and Lawn
However wet the snow is, it collects on your roof and on your lawn, trees, sidewalks, and driveway. When it melts as the temperatures warm and the sun comes shining through during the day, the resulting water saturates the soil while rooftop runoff adds to the already inundated soil.
The snow has also been stacking up around your home. That might be from drifting snow around your walls and foundation as well as from the build-up from shoveling snow off sidewalks and driveways. That, too, starts to melt, adding still further to the already oversaturated soil.
Snowmelt and Freezing
Daytime snowmelt is followed by nighttime freezing. That forms ice on the roof and often leads to frozen gutters and downspouts. All this develops ice dams that back up the snowmelt, causing further collection of water on the roof.
Another element at play could be insufficient attic insulation. This allows the heat from your home to escape through the roof, leading to even more melting.
Icicles forming around the edge of your roof might look picturesque, but they are actually a warning sign. Snow is melting on the roof. Gutters and downspouts are freezing. Ice is forming into ice dams and collecting ever more water for the coming thaw that will inundate your lawn and potentially flood your basement or crawl space.
Effects on the Foundation
Your landscape grading should be designed to help water coming from the gutters and downspouts move away from the foundation. If the gutters and downspouts are frozen, that water will flow directly off the roof and on to the area around your foundation.
If the soil is frozen, the water will collect into pools waiting for the next freeze. Even if the soil isn’t frozen, it will likely be saturated by the snow that’s been melting on the ground. While some of the water will likely move along the ground away from the foundation, a substantial portion will go underground, flowing toward the basement or crawl space.
This water flow is a result of the clay bowl effect. The soil around the foundation has a different drainage factor than the soil around your home. This happened as a result of the excavation when building the basement or crawl space. As the soil was backfilled around the new foundation, it essentially built a bowl that collects water.
The resulting hydrostatic pressure from the buildup of water from snowmelt can readily find any cracks as well as expand those cracks through alternate freezing and thawing. This leads to flooding.
What To Do About Snowmelt?
Prevention is the key to protecting your home from excess snow, ice, and the resulting snowmelt runoff. Here are our tips.
- Remove Rooftop Snow Buildup. Don’t climb on your roof adding weight along with the danger of sliding off. But you can use a roof rake from ground level to clear excess snow.
- Remove Snow Around the Foundation. First, clear the roof snow and then circle your foundation, clearing most of the snow to a distance of four to six feet. Then when the snow does melt, it will be well away from the foundation.
- Gutters, Downspouts, and Extensions. It’s important to first install correctly sized gutters and downspouts to carry the expected water from both rain and snow. Second, the downspout extensions along with the landscape grading need to move the water well away from the foundation.
- Sufficient Attic Insulation. Heat from the attic can melt rooftop snow, leading to ice buildup and the collection of even more water on the roof. Adding insulation to the attic helps prevent this and saves on energy costs.
- Foundation Insulation. Heat escaping through foundation walls can lead to snow melting around the basement or crawl space. This leads to soil saturation, hydrostatic pressure build-up, cracks, and flooding. Additional insulation can help prevent this and save on heating costs.
- Basement or Crawl Space Waterproofing. Install waterproofing measures such as an interior drainage system and sump pump that removes water before damage results. Fix any cracks in the foundation before they let in water or expand with freezing.
- Drainage System Maintenance. With existing sump pump systems, make sure the drain lines are working and the backup battery is fully operational. Freezing drain lines can be a big problem with a burned-out sump pump and the resulting water accumulation.
To schedule a free foundation inspection and repair quote as well as identify ways to improve your home’s insulation and waterproofing during winter, contact your local foundation repair experts at Complete Basement Systems.