An experimental procedure to quantify air intrusion in commercial roofing systems

The commercial buildings encompasses hospitals, schools, offices, lodging, and the retail sector with its big box stores, enclosed malls, strip malls, grocery stores and fast food restaurants Approximately one fourth of North American commercial buildings are roofed with Flexible Roof Systems (FRS) (NRCA 2004). In FRS, the waterproofing membrane is on the top exposed to the environmental forces with other roofing components such as insulation and cover board below it integrated to the structural substrate using mechanical fasteners. Field observations have identified that air intrusion in mechanically attached roof systems can affect roof system performance. However, the question of how much air movement occurs and which components provide the required resistance to air movement has never been addressed. To measure air intrusion in mechanically attached roof systems, an experimental study is recently completed at the National Research Council (NRC) of Canada as part of its Special Interest Group for Dynamic Evaluation of Roofing Systems (SIGDERS) research.Les b\ue2timents dits commerciaux englobent les h\uf4pitaux, les \ue9coles, les bureaux, le secteur de l?h\ue9bergement et celui des commerces de vente au d\ue9tail, incluant les magasins \ue0 grande surface, les mails commerciaux, dont les mails lin\ue9aires, les \ue9piceries et les \ue9tablissements de restauration rapide. Environ le quart des b\ue2timents commerciaux nord-am\ue9ricains ont comme couverture un syst\ue8me de couverture flexible (SCF) (NRCA, 2004). Dans les SCF, la membrane d?\ue9tanch\ue9it\ue9 se trouve sur le dessus et est ainsi expos\ue9e aux contraintes environnementales, tandis que les autres composants tels que l?isolant et le garnissage se trouvent en dessous, int\ue9gr\ue9s au support au moyen d?attaches m\ue9caniques. Les observations in situ ont r\ue9v\ue9l\ue9 que l?intrusion d?air dans les syst\ue8mes de couverture fix\ue9s m\ue9caniquement pouvait influer sur la performance du syst\ue8me. Toutefois, on ne s?est jamais vraiment pench\ue9 sur la question de l?ampleur du mouvement de l?air et de l?identification des composants pr\ue9cis qui procurent le degr\ue9 de r\ue9sistance requis au mouvement de l?air. Dans le but de mesurer l?intrusion d?air dans les syst\ue8mes de couverture fix\ue9s m\ue9caniquement, on a r\ue9cemment r\ue9alis\ue9 une \ue9tude exp\ue9rimentale au Conseil national de recherches du Canada (CNRC), dans le cadre du programme de recherche du Groupe d?int\ue9r\ueat sp\ue9cial pour l?\ue9valuation dynamique des syst\ue8mes de couverture (SIGDERS).Peer reviewed: YesNRC publication: Ye