Downspout Extensions

Underground DownSpout Extension in Chicagoland

Downspout Extensions

One of the most overlooked ways to help prevent excessive water buildup around your foundation is with a downspout extension. They can help to move rainwater and ensure that the discharge from the storm water sump is moved far enough from the foundation of your home. This can be done with a quality downspout extension. At ULB-DRY Waterproofing, we offer both an above ground downspout as well as an underground downspout option.


Above Ground Downspout

Above ground downspouts are quick and inexpensive to install. If you don’t mind lines that go above grade, this may be a good option for your property. The process consists of the following:

  1. The existing downspout line from the roof will be cut to allow a proper angle for the water to run away.
  2. A new section of pipe will be connected to the existing line and secured in place.

Underground Downspout

We also provide a subsoil technique that keeps the spouts hidden from view. To install an underground downspout, we will…

  1. Cut out and remove the sod, placing it to the side to be reset upon completion.
  2. Excavate a trench by hand. This trench will be a minimum of 6″ inches deep and slope a minimum of 1/8″ per foot towards the termination. Idealistically you would want a discharge;this is when the water flows directly out of the line without an upturn. However, in the situation where grade does not allow for this, we will utilize either a bubbler pot or a larger basin to be determined by water volume.
  3. A small bed of stone is laid in the base of the trench. If a bubbler or basin is required it will be surrounded with stone.
  4. A 4″ SDR 26 PVC line is installed with a direct connection to the downspout line. To help the water drain out, the last section of the line is perforated rather than solid.
  5. The substantial portion of the line is covered with soil while the perforated section is surrounded with stone.
  6. The sod is replaced.
  7. The area will be raked level, with all remaining soil removed and disposed of properly.


For more information about a downspout extension, contact ULB-DRY Waterproofing. Call 708-978-7558 for pricing and scheduling today!