Five Key Waterproofing Focus Areas

HGA’s Kevin Donaghey offer tips in considering the following specific areas where water can present challenges.

1. Above-grade Walls
It’s important to acknowledge that most exterior materials will take on rainwater at some point over the life of the building, and that an exit route for this water should always be accounted for in exterior wall assemblies. Rainwater should be viewed not as a passive element, but a force actively trying to penetrate the exterior barrier’s lines of defense. Analyzing exterior assemblies through this mindset can help to identify and provide adequate drainage pathways out of a rain-screen system for water that has found its way in.

2. Below-grade Systems
Ground water from surface rainfall or the water table, and its ability to infiltrate large areas of earth and into foundation systems, can be easily underestimated. Diversion of storm water run-off, extensive below-grade drain tile systems, and comprehensive membrane waterproofing at below-grade foundation walls can all serve to keep water out.

3. Roofs
Selecting a roofing system that meets the owner’s criteria for performance and budget can be a challenge, with reduced membrane thickness or warranty coverage being a tempting cost-reduction measure. We encourage the owner to err on the side of caution with roofing selection, even if it means adjusting project scope elsewhere.

4. Windows and/or Skylights
Skylights are typically more horizontally orientated than exterior wall window systems, and thus run a higher risk of water infiltration. Even with adequate slope, it is important that skylight assemblies be equipped with drainage channels, gutters and drop edges to usher rainfall onto the roof, and away from the skylight frame/roofing transition, which typically serves as the most susceptible part of the assembly. This can serve dual purposes (Example: the Language Arts and Humanities Building at East Los Angeles College features sloped skylights at a third-floor courtyard situated over occupied space, which funnel the rainwater into adjacent concrete planter boxes).

5. Doors
Doors located on exterior walls with exposure to the elements will pose increased risk of water infiltration. Drip edges, especially at the horizontal portion frame head, will divert water that would otherwise work its way inward.

This article originally appeared in the issue of .

Featured

  • Embry-Riddle Breaks Ground on New Office Building

    Embry-Riddle Aeronautical University (ERAU) in Daytona Beach, Fla., recently announced that construction has begun on a new office building for its campus Research Park, according to a news release. The university partnered with Hoar Construction on the 34,740-square-foot Center for Aerospace Technology II (CAT II), which will be used for research and lab purposes.

  • South Texas K–12 District Debuts Region’s First Electric Bus Fleet

    The Valley View Independent School District in Pharr, Texas, recently announced a partnership with Highland Electric Fleets to launch the district’s—and the region’s—first fleet of all-electric school buses, according to a news release.

  • UNT Dallas Holds Ribbon-Cutting Ceremony for $100M STEM Building

    The University of North Texas at Dallas in Dallas, Texas, recently celebrated the opening of its new, $100-million STEM Building, according to local news. The ceremony on Dec. 2 preceded the first day of classes in the facility on Jan. 12, 2026.

  • Texas State University Completes Stadium Renovations

    Texas State University in San Marcos, Texas, recently announced that it has completed a series of additions and renovations to its football stadium, according to a news release. Formerly known as the Bobcat Stadium End Zone Complex, the Johnny and Nathali Weisman Football Performance Center is an 85,000-square-foot expansion featuring hospitality spaces, banquet spaces, exterior concourses, and upgrades to the field house.

Digital Edition