By: Doug Hastings, ACI
Updated: January 29, 2019
A sump is a basket or pit that goes into the floor of a basement and collects water; it is typically about 3-feet deep. In extremely high water table situations, they can be up to 6-feet deep. The sump is required to have a cover that is screwed down to protect children and pets from drowning. A sump pump removes water from it. Drain tile is a continuous plastic pipe with holes or clay pipe with open joints. Typically the pipe goes around the entire perimeter of the foundation below the floor slab and alongside the footing. Drain tile can be installed on the interior or exterior of the foundation, and the pipes terminate in the sump.
Many homebuyers and real estate agents have the perception that a sump pump and drain tile indicate a problematic house, something they should walk away from. If you plan to become a home inspector, you need to understand that nothing could be further from the truth. When this system is installed properly it will really work. Soil conditions will impact the exact type of installation, and the elevation of the water table will determine how often it will need to operate. But, when these two factors are considered, this method of water control is very reliable.
Why the Uneasiness About Sumps and Pumps?
Sumps and pumps have evolved over the years. Old drain tile systems were made with clay tiles and placed directly in the dirt. Because of the brittle material and open joints, they are prone to becoming damaged or plugged with silt. It’s not uncommon for this condition to exist in many homes today. This is one thing that makes people uneasy.
Home inspectors know about another risky system called the “beaver system.” This is a plastic or metal diverter that sits on top of the basement floor slab. It is about 4 inches high and is glued to the foundation on the top and the floor slab at the bottom. Holes are drilled into the blocks allowing them to drain, and the diverter channels the water to either a floor drain or sump. This is not a drain tile system. It is an inexpensive, non-invasive, low-quality method of managing wet basement walls. If the diverter glue fails, the basement gets wet. Most systems fail miserably.
Both of these systems are concealed, either below the basement floor or behind finished walls. So, how can you tell if either of these risky conditions persists? It’s simple. Find the basement floor drain. Most drains are on the surface of the floor, but sometimes they are below a wood or metal cover plate that you must lift up. These old systems will drain directly into a plumbing floor drain, which actually does indicate the problem home that home buyers and agents fear.
The Reliable and Dependable Sump and Pump Systems
Newer drain tile systems are embedded in gravel and made with a continuous plastic pipe with holes. These pipes are more durable and are covered with a silt screen fabric that keeps them from becoming plugged. The sump pump will be discharged into the yard and in some instances, there will be an additional battery backup pump. These systems are very reliable. Home inspectors can point them out to put the homeowner, buyer, and the real estate agent at ease.
How would you recognize this type of dependable installation? Take the cover off the sump basket and look inside. If you see two 4-inch pipes coming through the side of the basket, the basement is drain tiled and dependable. If there are no pipes, the basement is not drain tiled and may be undependable.
If you like the idea of searching out problems to make sure home buyers are aware of what they’re purchasing, or simply letting them know that sumps and pumps are good news, consider becoming a home inspector. You can check out our home inspection education offerings here.