Beating the Soggy Basment Blues — Don’t Panic
By: Patrick Hooper
Though not all that uncommon, water in the basement is a serious problem that can damage walls and floors, destroy carpeting, ruin furniture, lead to mold—a very dangerous and expensive problem to eliminate–and create the perfect breeding ground for termites and cockroaches, to name a few. Even if a basement is not finished, more than likely it is being used for the storage of irreplaceable items like photo albums, antiques, and family heirlooms. The bottom line is that if you are experiencing a wet or flooded basement you have a very serious problem that must be fixed.
Many homeowners are unaware that without additional flood insurance, they will be financially responsible for property damage, costly cleanups and the potential damage and/or loss of property resulting from a flood. And, even with the additional coverage, many insurance companies will require that you pay a deductible, may increase your premiums, choose not to cover a second backup and could possibly even revoke your policy.
Now, as scary and expensive as this may sound, it isn’t always all “doom and gloom”. There is more than one way in which water can make its way into the home. While some causes may require extensive and costly work, other reasons may need nothing more than very simple, inexpensive remediation. Determining where the water is coming from is essential to solving the problem. So, let’s explore the common causes of wet basements.
Beyond observable flooding around your home and in your neighborhood, there are four common sources of water entering basements.
1. Surface Water
One of the most common causes of water in the basement is also one of the easiest to fix. As long as they are operating properly, gutter systems are something we tend not to think about, however, gutters are one of the most critical components to a home. A 2000 square foot roof can displace more than 1000 gallons of water with just 1 inch of rainfall. Gutter systems are designed to funnel this water away from the foundation. If they are not functioning correctly, gutters may direct water to the very place you do not want it, becoming the foundation’s own worst enemy.
Overflowing Gutters: Leaves
Preventative maintenance should be performed at least twice a year by thoroughly cleaning and removing all debris from both the gutters and downspouts. Depending on the number and kind of surrounding trees, this may need to be done more frequently. There are also products available designed to prevent leaves and debris from making its way into the gutter.
Overflowing Gutters: Downspouts
This is easy to check, as long as you do not mind getting a little wet. Thoroughly clean all of the gutters and downspouts, being sure they are free from all debris–and then wait for the next heavy rain fall. After about 10 minutes of rain, do a walk-around and visually check all of your gutters. If you see any water overflowing, you have a problem. This overflowing water can run down the side of the house and settle at the foundation. Even if the water is not getting into the basement, it could be eroding soil from under the house footings, which can lead to cracking of walls and ceilings.
The two best solutions for overflowing gutters are to either add another downspout on the run of overflowing gutter or increase the size of the downspout. I believe the preferable and most cost-effective of the two solutions would be the additional downspout as it may serve as a backup should the other become blocked and/or overwhelmed.
Ideally, downspouts should extend at least 10 feet from the home. However, depending on the slope of the yard moving away from the foundation, a shorter distance may be sufficient. While many homeowners do not like downspouts extending out this far, with flatter yards, 10 feet is the minimum distance needed to discharge water coming off your roof far enough away from the house.
Many homes in the Cincinnati area have down spout lines– underground drain pipe that gutters feed into. This downspout line may “daylight” at some point in the yard away from the house, connect into a storm sewer, underground French drain, or in many older homes, tie directly into the existing sanitary sewer line. Often times older downspout lines, made mostly from clay or in some instances “orangeburg” pipe, are cracked, corroded and even collapsed, resulting in a blockage that can cause water to back up in the pipe and collect at the foundation. Additionally, newer homes with downspout lines made from an insufficient grade of PVC pipe often result in compressed and/or crushed pipe, resulting in the same kind of backups.
Pavement around the foundation can settle over time, reversing the direction of water flow towards the foundation. If this is the case, the paving should be removed and replaced so it slopes away from the home.
Sealant around pavement that abuts the house sometimes cracks over time due to age or incorrect installation. If the sealant is cracked, it must be removed and replaced with new sealant.
The yard or the land around your house should slope away from your home/foundation. Look for any depressions in the ground next to the home foundation walls. If any are found, fill in with dirt so the water drains away from the house. Use a clay-type soil that sheds water instead of sandy soil that allows water to soak into the ground. Make sure that at least eight inches is kept between the top of the earth and any wood or stucco on the house. If there are large hills nearby sloping toward your home, and you think they may be causing the problem, a civil engineer may be required to analyze the situation and determine the appropriate solutions.
Avoid placing lawn irrigation next to the house. If this cannot be avoided, instruct the installer to limit the amount of water dispersed next to the house. Make sure the irrigation system includes a working rain gauge so the system does not turn on when there has already been plenty of rain for the plants and lawn.
With of a bit of good investigation work and problem solving, future basement floods can be avoided.
2. Subsurface Groundwater
If no surface water sources are found, then the source of the water is likely subsurface groundwater under hydrostatic pressure. Unfortunately, subsurface groundwater problems are more difficult and more expensive to fix than surface groundwater problems.
When the groundwater levels outside the basement rise above the level of the floor, the basement acts like a boat in a pond. If a boat is sitting in water, water will leak in through any open cracks or holes. It works the same way with a basement. Hydrostatic pressure can push water through hairline cracks.
Symptoms of this are water coming up through cracks in the basement concrete floor or water coming in at multiple locations.
If you have an older house that has a basement with no sump pump, it’s possible that the perimeter foundation drain system connects directly into the city storm sewer system. If the level of the basement is below the street level, there is the potential of storm water backing up in the city storm sewer system and being pushed into the perimeter foundation drain system. This can saturate the soils around the house at the basement level with storm water under hydrostatic pressure, causing water to leak in.
No matter where it is coming from, the best way to control subsurface groundwater is to install some type of perimeter drain system to relieve hydrostatic pressure. The groundwater is pushed into the drain system and not into areas where it can damage carpets, walls or belongings. The water drains by gravity into a sump pit where a sump pump discharges it out of the house.
There are two basic types of drain systems for wet basements. One is a perimeter above-slab gutter system installed at the base of the exterior foundation walls on top of the floor slab. It doubles as a base material for the wall. The other type of drainage system is a below slab perimeter drainage system. The below slab system requires the partial removal of the concrete floor slab and installation of drainage pipe, making it more expensive than the base gutter system.
It is believed that an under-floor drainage system is better because the under-floor drains are believed to relieve the hydrostatic pressure before the water reaches the bottom of the floor slab.
3. Storm Water Backing Up Into Your Home
In many older houses with basements (mostly pre-1980), there is a perimeter foundation drain outside the exterior wall, at the level of the basement floor, next to the footings at the time the house was built. A pipe was usually installed from the perimeter foundation drain to the street where it was connected to the city storm sewer system.
This can become a problem as the city storm sewer system becomes too small when more development causes more rain runoff. When this happens, the rainwater in the sewer system can get so high that water flows backwards toward the house.
Usually, the installation of an interior perimeter basement drain system connected to a sump pump will take care of the problem. If it doesn’t, the (more expensive) alternative is to dig up and cap the pipe that is running from the house to the street from the perimeter foundation drain. However, this is not always possible; many times, this pipe is also draining sanitary waste from toilets and sinks in the house.
4. Sanitary Sewer Water Backing Up Into Your Home
If the water is coming up through floor drains or sink drains in the basement, then the problem is often water backing up from the municipal sanitary sewer system. During heavy rains, combined sewer systems can become overwhelmed with water. This can cause sewer water to back up in the system and sometimes into homes.
There are other possible explanations, too. Sewer backups can be caused by individual service lines being plugged by grease, waste, tree roots, breaks in pipes or saturated ground. Sewer mains can also be plugged by vandalism or large items dropped down manholes.
Additionally, in many older homes it was not uncommon to tie downspout lines directly into the sanitary sewer line. Once thought the most logical means of moving storm water away from the home, increased populations made it difficult for the water treatment plant to keep up with the volume of water moving through system. If one of these homes has any kind of existing restrictive issues in the main sewer line (as described above) the added volume of storm water during a heavy rain can overwhelm the pipe and result in a backup and flood.
This kind of flooding is an enormous problem for homeowners, as it’s largely out of your control and probably means fecal waste backing up into basements. Not only is it disgusting, but it can also be a serious health hazard.
In order to keep your individual lines clear, you can install back-flow preventers/valves that help stop sewer water from flowing backward into the house. Proper maintenance of your individual lines – for example, pouring tree root killer down your toilets once a year – can also go a long way in preventing sewage backups. Still, the problem is often out of your control.
Sewage in your basement means a major cleanup and a lot of uncertainty about future problems. If it’s something you’ve seen in your home that does originate in the municipal sewer, you may need to get your city government involved. At the very least, be aware of the problem and don’t leave anything valuable near your downstairs drains.