Restore Concrete Box Culvert substructure drainage with Weep Hole Filters

Concrete box culverts have unique hydrostatic drainage challenges. As they are buried underground, hydrostatic pressure can build up on all four sides. In addition to the pressure on both walls, there may be downward pressure building up on the top slab and uplift pressure on the base.

closeup photo of

Of the approximately 135,000 box culverts in the US, over 101,000 are 30 years or older. Fortunately, the vast majority are in Good or Fair condition.


  1. Keep “Good” culverts from becoming “Fair“.
  2. Keep “Fair” from becoming “Poor“

Our 3″ and 4″ units are recommended for box culvert applications. The choice for open vs. closed-end units depends on the particular application. Call us for more information at 1-800-475-2029.

Play Video

Michigan DOT uses Maintainable Weep Hole Filters to restore drainage of hydrostatic pressure off concrete box culvert walls to eliminate pressure on the top slabs and reduce the uplift pressure on the base.

Find additional information:
1) Full-length installation video on this page. It is 6 minutes long. To view Coring or Installation, only videos visit the MDOT ITD Project page.
2) Results in MDOT Innovative Technology Demonstration Project with MDOT, LS Engineering, and AASHTO’s Bridge Preservation Partnership.
3) MDOT Box Culvert Case Study I-96 & 68th Street in Coopersville, MI

Follow us on social

Contact us

Have a question with us?