When: Tuesday, September 22, 2026 from 12:00 PM to 1:30 PM CT
Where: UrbanWorks Office, 125 S Clark St #2070, Chicago, IL 60603 & Virtual
Details:
A Rated Wall ≠ Rated Joint
Why Bottom-of-Wall Joint Protection Matters
Specifying a rated wall assembly is only part of the detail. What protects the joint where that wall meets the floor?
We’ll begin with why drywall is held above the slab, the purpose of GA-216’s floor-clearance requirements, and how moisture wicking can create conditions for mold growth at the base of walls.
The International Firestop Council’s research examined 19 bottom-of-wall configurations across five laboratories using UL 2079 methodology. All six protected systems met the targeted one- or two-hour test criteria. All 13 unprotected conditions failed to achieve their targeted rating. Read the IFC white paper (https://firestop.org/wp-content/uploads/2025/12/Closing-the-Gap.pdf).
Join Michael Denman for a 45-minute discussion of what these findings mean for architectural details, specifications and construction. We’ll examine the distinction between wall assembly ratings and joint system ratings, how unprotected gaps affect fire and smoke containment, and why a gap or an installed baseboard does not establish joint protection.
Learning Objectives:
- Explain why drywall is held off the slab, including the purpose of GA-216’s floor-clearance provision and its role in reducing moisture wicking and conditions that support mold growth.
- Distinguish a rated wall assembly from a rated joint system and explain why the wall’s fire-resistance rating alone does not establish protection at the floor connection.
- Use the IFC’s comparative test findings to explain the consequences of unprotected bottom-of-wall joints, including fire passage and temperature rise, and the implications for occupant safety.
- Identify the information needed to detail, specify and verify an applicable bottom-of-wall joint system, coordinating drywall clearance with fire and smoke protection before finishes conceal the installation.
1 AIA Credit (PENDING)
Presenter:
Michael Denman
Waterguard
Michael Denman has more than three years of direct experience focused on base-of-wall conditions in commercial construction through his work with Waterguard. His work has required detailed study of how gypsum wall assemblies terminate at the floor and how those conditions affect fire resistance, smoke and air leakage, acoustical performance, moisture protection, and constructability.
He has been directly involved in reviewing and interpreting third-party laboratory testing, listed assemblies, and the standards used to evaluate both walls and joints, including the important distinction between wall-assembly testing under ASTM E119/UL 263 and joint-system testing under ASTM E1966/UL 2079.
Michael's experience also includes working with architects, contractors, testing laboratories, and industry professionals on the specification and performance of base-of-wall systems. This combination of field, product-development, testing, and specification experience gives Michael a practical and technical understanding of the base-of-wall condition and the issues addressed in the IFC white paper.
RSVP (Lunch provided): $0 members & non-members
We will have both an in-person and virtual option available.