Originally published in the February 2016 issue of Sweeping Magazine
Question: What is the correct or best way to secure pipe section joints in a dryer vent system?
by Mike Segerstrom
The existing codes and standards don't give us much to go on for this one. We are not permitted to use screws or rivets, or anything that penetrates the inside of the pipe. But that's about as far as it goes.
For a question of this type, I thought I would talk to industry expert John Bently, owner/operator and lead technician of Duct Doctor, LTD located in New Richland Minnesota. He is an instructor for the CSIA, serves as the CDET Committee Chair, and was a main contributor for the recent revisions to the CDET Manual, test, and training program.
John says that we should use a high temperature foil tape at the joints. He goes on to explain that we should think of tape at these joints as something to seal them, not secure them. That we shouldn't rely on the tape to hold the pipe sections together, or stabilize them.
When replacing or repairing an existing dryer vent, or installing a new system, John says that we should use straps, brackets, and/or clamps to keep the piping in place. That way if the tape ever fails, over time or even as the result of cleaning the system, the piping won't disconnect. And in addition to taping the pipe joints, he says that we should also tape the seams and the joints in adjustable elbow sections.
Another thing that we should consider John says, is maintaining an air space clearance from our dryer vent to combustibles. We have all heard about them, and some of us have clients who have experienced a dryer or dryer vent fire. In some of these cases, the fire in the dryer vent caused the ignition of adjacent combustible construction of the home. These types of losses can be catastrophic. Though not required at this time by code, if we maintain a clearance to combustibles, we may be able to prevent a structure fire in the event of a dryer vent fire.
Just because the existing codes and standards are limited in dryer vent installation requirements, that doesn't mean we can't exceed these requirements. They are after all, minimum codes and standards.