b'1.The above three pipe conditions are common in Part 3 Pipes with associated securing rods (Photos 4 to 6): The close proximity of the two securing rods to the pipes makesconstruction. The core of the issue has been mainly due to the the installation of proper waterproofing detailing chal- lack of the necessary coordination. In reality, proper water-lenging. And in the case of sheet-applied waterproofing, it isproofing of these pipe conditions requires diligent coordination practically impossible (Photos 5 & 6).between several key disciplines including the architect, building 2.Pre-insulated hot and cold non-metallic water pipesenvelope consultant, mechanical engineer, below-grade water-proofing manufacturer, pipe manufacturer and pipe installer. with a waterproof, corrugated high-density polyethyleneDue to the overlaps between these disciplines, one of them, (HDPE) jacket (Photos 7 to 9): The corrugated profile ofpreferably the building envelope consultant (or the architect), the HDPE outer jacket does not provide the appropriateneeds to take on the role of coordinating such overlaps for the surface for the application of the waterproofing membraneproper design and site implementation. Below are examples of onto the jacket. Moreover, some below-grade waterproofingthe recommended necessary coordination measures for each of materials do not adhere well onto the HDPE jacket. the three pipe conditions described above.3.Main hot water supply (HWS) and hot water return(HWR) pre-insulated metal pipes with a thin-walledRECOMMENDATIONSHDPE jacket (Photos 10 & 11): Similarly, some of the1. Pipes with associated securing rods: At least a four-inch commonly used below-grade sheet applied and liquid- clearance needs to be provided between the pipes and the applied waterproofing membranes do not develop theadjacent rods to leave sufficient room for the application of required adhesion onto the HDPE jacket. Furthermore,the waterproofing detailing. A liquid-type waterproofing there have been concerns with the chemical compatibilitymembrane is recommended for this application (Photo 12), between the two.preferably applied with a brush to allow for a controlled PHOTOS 7 (FROM THE UPONOR WEBSITE), 8 & 9.PHOTOS 10 & 11.SPRING/SUMMER 2024 17'