09/01/2023
Seepage 101
Having a dry basement should always be a priority. If I have completed a Home Inspection for you, I always emphasize that water will be your biggest enemy. When buying a home or owning a home people often dismiss stains on basement walls because it hasn’t created water damage. Staining can be both a symptom for neglected exterior maintenance, an inherit poor building design, or the combination of both. Staining indicates that water has entered the basement before, which is not unusual considering basements are a huge hole dug into the ground. Whether it be storm water, roof water or a plumbing leak, basements will eventually have dampness. Homes built during different decades will have different risk factors based on the building materials and methods available at that time. I have accumulated a lot of knowledge and details about seepage in my career and it’s time to breakdown that info. This is one of three articles I will post to help new or current homeowners assess their risk for seepage based on the age of home. This will include the flaws, benefits and common solutions for homes built before 1950, 1950-1970 and the current standards we now have in Southeastern Wisconsin.
Article #1 - Older homes: Majority of the homes built before the 1950s have no underground water management system and have the highest risk for chronic seepage and related damages. These homes rely solely on the grading around the home - which is both the slope of the soil and concrete surfaces adjacent the foundation, like driveways, sidewalks and patios, and also the proper use of gutters and downspouts. The overall theory 100+ years ago is to divert water as far away from the basement walls as a prevention method. However, after decades of trial and error, it has been concluded that trying to keep water away from a home and using the foundation as a barrier does not have a high rate of success.
*BONUS INFO - People often think painting the wall with a specialty paint, like Drylok, is the answer to prevent seepage. That paint will temporarily prevent seepage up to a minimal amount of water pressure. Once again, this is the old train of thought and not recommended. The paint will prevent a certain amount of water to enter the basement but will also trap any water behind the foundation wall which can lead to hydrostatic pressure and subsequent foundation movement during our Wisconsin seasonal frost heave cycles.
Preventing roof and storm water from coming close to the home is still recommended to homeowners who own older homes to help lower the risk of water intrusion; however, there is a solution to help greatly reduce that ongoing risk. Newer building standards still require that roof and storm water discharge as far away from the home as practical, but unlike the design of older homes, any roof or storm water that saturates the soil around a new home will not enter the basement, but will enter a drain tile system that is below the basement floor and surrounds the home’s perimeter. Instead of preventing water to enter the basement, modern building standards now advise contractors to let that water flow freely into a designed drainage system called drain tile. This water will eventually enter into a sump pump basin that will pump the water into a well-drained area of your yard, ideally as far away from the home as practical. With proper grading and downspouts, less water will enter this system and reduce the stress on the sump pump’s performance.
It is possible to install a complete drain tile and sump pump system in older homes but this process is invasive and a very costly installation. (I have seen invoices between $5,000-$30,000 to install this system). It also should be noted that if a foundation has decades of moisture issues from improper grading and roof water management, foundation repairs are very common and will increase the overall repair cost.
Here is the good news. If the water around your home is seeping through the walls, it is assumed that gravity would allow the water to pond below the basement floor also. During heavy rains, people often see seepage through basement floor cracks indicating water pressure below the home. To help reduce the risk and cost, a contractor can cut a small square hole into the concrete basement floor of an older home, clear out the soil and stone within that area and install a sump pump creating a make shift basin. Installing a discharge pipe that allows any water that enters that new basin would then be pumped into a well-drained grassy surface in your yard. Does this work? This much less expensive system has been successful in greatly reducing the risk for chronic seepage. How much does it cost? Around $2000, rather than $5-20k. I have been recommending this type of stand-alone sump pump system for over a year but very few people are aware or not familiar with this type of newer, cost-effective solution. If you own a home built before 1950 and have a wet basement, you should consider getting a quote for a stand-alone sump pump.
My next article will help homeowners understand the variety of drainage systems installed during the baby boomer area of the 1950s and 1960s. Contractors were trying a combination of improvements including a very specific invention called a Palmer valve that was not common in other areas of our country. (Spoiler alert, these systems have proved to be unsuccessful)
Stay tuned and enjoy your Labor Day weekend!
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