How to keep water out of your basement
When I first bought my home in Fitchburg, I noticed that the corner of the basement collected a puddle of water after rain storms. I thought, “Oh well, this is something I have to live with. The house is 35 years old after all.” The next time I mowed my lawn, I noticed the gutter extension had fallen off the gutter. I put the gutter extension back in place. After the next rain storm the basement was dry. That was several years ago. I’ve never had water in the basement again, just by making sure the gutter extension is in place.
Here are things to consider to keep water out of your basement:
Grade landscape away from the house.
Add gutter extensions and keep gutters clean.
Ensure your sump pump (and backup) works.
Check for roof and window leaks.
Provide foundation and wall waterproofing.
Install a drain tile system with a sump pump.
Grade Landscape Away from the House
Water that is right next to the foundation of a home tends to find its way into the basement. Even if your home has a tile system and sump pump, and even if the foundation is coated to waterproof it, why tempt fate? Besides, keeping water away from the foundation is a good way to ensure the foundation remains structurally sound. The foundation rests on soil. Soggy soil can either swell or sag, which can lead to cracks in the foundation, heaving of the foundation, or settling of the foundation.
Water needs to flow away from the house, not toward the house. A best practice is for the grading around the house to slope away from the foundation at least 6 inches in the first 10 feet. You may be able to add soil next to the foundation to get this slope. Make sure you keep an adequate clearance between the soil and the house siding so that insects and mice do not get behind the siding. A 6 inch clearance is needed for wood siding. Other types of sidings or veneers (including brick and stone) usually require a 4 inch clearance.
If you can’t add soil to get the necessary slope, you may be able to remove soil to create a swale (a shallow ditch) that directs water around the foundation. If this isn’t possible, it may be necessary to add an underground tile system (French drain) to redirect the water away from the foundation.
When I inspect homes I often see a flowerbed between a sidewalk and the house. Water can collect here, next to the foundation, where it can cause problems. It is better for the flowerbed to drain naturally away from the foundation. Be especially careful of watering plants right next to the foundation. It may be better to use drought resistant landscaping that requires minimal watering than to water flowerbeds and end up with water in the basement or a weakened foundation.
Add Gutter Extensions and Keep Gutters Clean
Gutters collect the water from the roof and get the water away from the foundation. If the gutter is clogged, the water will drip right next to the foundation. Clean the gutters once in the fall and once in the spring. Gutter extension should be at least 5 feet long so that water keeps away from the foundation. It is better to have no gutters at all than to have gutters without a proper extension of 5 feet or more. With no gutters, the water is at least spread out along the foundation. But if there is no extension, the water is all concentrated in one spot. Get that water at least five feet away from the foundation!
Ensure Your Sump Pump (and Backup) Works
Some homes have a tile system which collects water that would otherwise seep into the basement and drains the water to a sump pit. A sump pump then pumps the water out before it gets the basement wet. This works great - unless the sump pump fails! I recommend that the sump pump be tested monthly. If the sump pump has a float switch, you can raise the float lever to see if the pump activates and expels water from the pit. If the sump pump has a pressure switch there will often be two electrical plugs: one for the pressure switch and one for the pump. These plugs are “stacked” with the sump pump plug inserted into the pressure switch plug, and the pressure switch plug inserted into the electrical outlet. You can test this type of pump by unplugging the plug for the pump and plugging it directly into the electrical outlet. Don’t forget to return it to the original configuration.
If you do have a sump pump, it is a good idea to have a battery operated backup. A heavy rain storm may be the most likely time when the electrical system may fail, and that is exactly when the sump pump is most needed.
Check for Roof and Window Leaks
Water from a roof leak, or from a window that is not properly flashed and sealed, can find its way down the interior of the walls into the basement.
Provide Foundation and Wall Waterproofing
Newer homes should already have a waterproof coating applied to the exterior of the foundation. If the foundation cracks, that seal may be broken. Sometimes the crack can be repaired from the inside using an epoxy product that is squirted into the crack. Older homes may be missing a waterproof coating. Sealing from the inside might work, but it is more likely that a waterproof coating needs to be applied to the outside. Adding that coating can be expensive, since the dirt must be dug away from the foundation in order to apply the waterproofing. If you are going to that much trouble, consider installing a drain tile system with a sump pump (if those are not already present) as well.
If the foundation has cracks where the wall has moved more than about 1/8 of an inch in any direction, consult with a structural engineer to determine if more extensive foundation repairs are needed.
Install a Drain Tile System with a Sump Pump
If your home doesn’t already have a drain tile system and addressing the issues described above does not solve the problems, consider adding a drain tile system. Interior drain tiles run around the perimeter of the foundation on the inside of the foundation. Exterior drain tiles run around the perimeter of the foundation on the outside of the foundation. Bleeder tubes allow water from the outside tiles to drain into the inside tiles. The water collects in a sump pit where a sump pump ejects the water from the house. Since installing the exterior drain tiles requires digging dirt away from the foundation all around the house, this is also an opportunity to apply foundation waterproofing to the exterior of the foundation.
A Home Inspection May Help
When I do a home inspection, I not only look for evidence of water in the basement, but I also look for things that can result in water in the basement - like a missing gutter extension, inadequate slope of the soil away from the foundation, or a sump pump that doesn’t work.
