Continuation of Part 3: The challenge: cables passing underneath joists
The number of pipe feed-throughs through airtight layers is increasing continuously. The familiar vent pipe for the sanitary drain pipe is no longer the only candidate by any means! However, installation technicians for domestic hot water heating, photovoltaic systems and ventilation systems often show little consideration for this issue. Damage can be avoided by careful planning and early intervention. A lot of prefabricated solutions are now available that can be implemented quickly and cost-effectively.
A typical error when sealing pipe feed-throughs: this adhesive seal is not airtight as creases occurred when applying the tape. These creases are often not noticed and are only shown up by a blower door test. 
Solution that can be implemented by tradespersons to properly seal pipes: short pieces of tape are applied along the pipe and the sheeting, all around the pipe. This is very time-consuming.
This series of articles summarises typical, challenging joint situations and shows how technicians can find practical solutions for these challenges. It also provides an overview of the detail features for which prefabricated solutions are available that allow tradespeople to achieve airtightness in a quick, easy and reliable manner.
This Series was wirtten by Jens Lüder Herms and Holger Merkel
Jens Lüder Herms, carpenter and graduate engineer, Export Manager and Application Technology specialist, pro clima Research and Development,, www.proclima.de. He provides insights into his work on Twitter and Instagram.
Holger Merkel, provider of blower door measurement services, speaker at the pro clima Knowledge Lab and instructor for certification courses.. He has documented examples of leaks in his most recent project www.zieht-wie-hechtsupp.de. He also publishes specialist articles on issues such as blower door tests on www.airtight-junkies.de.