Skip to main content
Add as a preferred source on Google

Five Key Waterproofing Focus Areas

  • 12/01/16

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

  • Academy of Classical Education Breaks Ground in Louisiana

    Charter Schools USA (CSUSA) recently announced the groundbreaking of a new public charter school in Covington, La., according to a news release. The Academy of Classical Education at Covington will enroll students in grades K–8 and is scheduled for completion in August 2026, just in time for the new school year.

  • Arizona District Breaks Ground on Community Training, Learning Center

    The Tolleson Union High School District (TUHSD) in Tolleson, Ariz., recently broke ground on a new Training & Learning Center (TLC) for both district professionals and the community at large, according to a news release. The 90,000-square-foot facility has an estimated completion date of spring 2027.

  • University of Arizona Approves New Residence Hall

    The Arizona Board of Regents recently approved plans for a new residence hall at the University of Arizona in Tucson, Ariz., according to a news release. The new facility is scheduled to open in fall 2028 and have the capacity for more than 1,200 students, enforcing a new university expectation that all first-year students live on campus.

  • From Approval to Opening: Inside Travis Unified School District’s Fast Tracked Campus Expansion

    The Travis Unified School District (TUSD) in northern California includes several elementary and high schools serving over 5,400 students. In 2024, the TUSD Board approved the addition of sixth grade to the Golden West Middle School campus for the 2025–26 school year, setting in motion an accelerated effort to bring new facilities online in less than a year.