b'BELOW-GRADE WATERPROOFINGKEY CONSIDERATIONS FOR BELOW-GRADE PIPE WATERPROOFINGBy Hamid Heidarali, P.Eng.D espite substantial progress and advancement in theHowever, due to the high cost associated with the excavation, development of below-grade waterproofing prod- especially for deep foundations, the remedial measures have ucts and systems in North America, unfortunately,been mostly focused on the inside utilizing methods such as the proper waterproofing of certain below-gradespray foam, caulking, injection, etc. Experiences have shown pipe conditions has still not been given the neces- that these interior remedial solutions are generally not long-sary attention. Based on the experience of theterm fixes, and in some instances, can exacerbate the situation author, a wide range of projects experience water ingress fromby directing water to adjacent areas.around such pipes within five years after the completion of theBased on the information collected from several investigative construction (Photos 1 to 3). This can result in nuisance forcase studies in the lower mainland of British Columbia, the end users and, in some instances, costly damages. Long-termfollowing three below-grade pipe conditions are found to be the repairs would require access from the outside of the pipes.primary subjects of concern:PHOTOS 1, 2 & 3.PHOTOS 4, 5 & 6.16 BCBEC ELEMENTSA BCBEC PUBLICATION'