OK, I realize the headline of this post sounds like the title of a new Indiana Jones movie but, sorry Indy fans; it’s just about keeping your basement dry.
Now that the film buffs have left the room, let’s talk about the Zone of Failure and what it means in keeping water out of your basement.
As you know, your home sits on a foundation that begins with footings at the very bottom, which are poured concrete slabs wider than they are deep to spread the load of the house across undisturbed soil. On top of these footings are foundation walls made of poured concrete, cement block or other masonry. They form the walls of your basement or crawlspace or, in the case of a slab foundation, underpin the ground-level concrete floor of your home.
When you find water in your basement, chances are that it came over, under or through these foundation walls. (Hydrostatic pressure can also force water up through cracks in the basement floor.) In order for that to happen, water has to be in the soil outside the foundation and that can come from various sources.
How the Zone of Failure Creates Basement Water Problems
- Heavy rains
- Clogged rain gutters
- Improper grading
- Downspouts that dump water next to the foundation
- Over-watering plants and shrubs or a leaking hose bib
What makes these situations worse is the fact that the soil immediately outside your foundation is not highly compacted and undisturbed but consists of backfill that was replaced after the excavation was done to build the foundation in the first place. Backfilled soil is more porous than undisturbed soil and it holds more water and allows more water to flow through.
This area of backfilled soil is what we call the Zone of Failure. It can be roughly measured by starting with a point at the outer edge of your home’s footings and drawing an imaginary 45-degree line through the soil away from the foundation wall. In a typical home with an eight-foot basement, this zone can be eight or more feet wide, depending on how the excavation was done.
There’s not much you can do about the Zone of Failure. It’s been there as long as your house has and you really can’t fix it. It’s just a consequence of building a house.
How You can Eliminate Sources of Water that Cause Seepage in Your Basement
- Clean and repair gutters at least twice a year
- Make sure your lawn is graded away from the house and not toward it. This includes materials like topsoil and mulch that have been added to planting beds
- Extend your downspouts at least ten feet away from the house. This will ensure that rain water from your roof is not being deposited into the Zone of Failure and significantly improves your chances of keeping it out of your basement
- Be careful about over-watering and make sure your outdoor faucet doesn’t leak. If possible, turn off water to the faucet from inside during the winter
Remember, you can’t fix the Zone of Failure but you can prevent it from causing seepage problems in your basement. At U.S. Waterproofing, we know how to solve these and other basement water problems so why not ask for a free consultation?