Home > How To > Exteriors > Making EIFS Watertight Exteriors Making EIFS Watertight Properly installed backer rod and caulk are the keys to a long-lasting, trouble-free application By Harrison McCampbell Login or Register to download the PDF version of this article. (338.53 kB) by Harrison McCampbell, AIAImproperly detailed EIFS joints allowed water to soak into the structure of this portico, with ugly and expensive results. Login or Register to continue reading