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

  • UT System Board of Regents Approves $108M Housing Complex

    The University of Texas System Board of Regents recently announced the approval of a new, $108-million housing complex at the University of Texas at El Paso (UTEP), according to a news release. The facility will stand four stories and have a total of 456 new beds for freshmen students.

  • Wisconsin District Breaks Ground on New Elementary School

    The School District of La Crosse in La Crosse, Wis., recently broke ground on a new elementary school that will consolidate the students and staff of two existing schools, according to local news. Funding for the school comes from a $53-million referendum approved in 2024.

  • UT System Approves First Funds for New Campus

    The University of Texas System Board of Regents recently approved funds to build the first facility of a new campus in far west Fort Worth, Texas, according to university news. UTA West will serve as a branch of the University of Texas at Arlington and is scheduled to open in fall 2028.

  • Utah Valley University Opens New Engineering Building

    Utah Valley University in Orem, Utah, recently held a grand-opening ceremony for the new Scott M. Smith Engineering Building, according to a news release. The facility is one of the largest engineering buildings in the state at almost 200,000 square feet, and it plays home to the university’s Smith College of Engineering and Technology (SCET).