b'TECHNICAL & RESEARCHWHAT HAPPENS WHEN SHEATHING GETS SOAKED? PREVIEW OF A GROUNDBREAKING STUDY TO BE PRESENTED AT THE 2025 MRCA CONFERENCEBy Megan Pope, MRCA Executive DirectorM oistureexposureduring*TheEffectofMoistureonOSBandPlywood constructiondelaysisSheathing*, this collaborative research effort with afamiliarchallengeforMRCA explores how moisture exposure affects the commercialroofingcontractors,structural performance of common roof sheathing especiallyinregionslikethematerialsspecifically, oriented strand board (OSB) Midwestwherespringweatherand plywood. The findings of the study will be unveiled is unpredictable. Roof decks on new constructionduring a featured technical session at the 2025 MRCA projects are often left exposed for daysor evenConference and Expo, taking place Wednesday, weeksdue to unforeseen scheduling changes,October 22 at the Schaumburg Convention Center material delays, or extended weather events. Duringin Illinois.this time, roof sheathing experiences multiple cycles ofThis initiative represents the second phase of testing wetting and drying before a roof covering is installed.by WJE, building on a 2024 program that focused But how much does this exposure matter? What isexclusively on OSB without the variable of moisture really happening to the materials that lie beneath ourexposure. Phase 2 introduces plywood into the mix, roofing systems? allowing researchers to compare both materials under A new study led by Wiss, Janney, Elstner Associates,similar conditions. Full-scale test framesconstructed Inc. (WJE) aims to answer that very question. Titledusing 1/2-inch OSB and plywoodare currently 26 www.mrca.orgMidwest Roofer'