1.89 in. x 60 yd. 557 Pro-Grade UL Listed Duct Tape Pro Pack (12-Pack)

A:  This tape is a UL approved tape and should work for your ductwork.

A:  Are you supposed to? I don't know. Can you? Yes.

A:  Yes, this can be used to seal up ductwork.

A:  Thank you for your question. Nashua 557 is UL 181B-FX listed for use on flexible duct sealing. It is not generally recommended for rigid duct sealing (which is commonly where mastics are used). For sealing rigid duct connections, we recommend Nashua Foilmastic tape (Home Depot Store SKU 1003055450). Best of luck with your project.

A:  I do not know about fire rating. This is the only duct tape that I have used for 20 years. If you are doing the work for a job that will be inspected, the inspector will be looking for certain numbers written on the tape. This tape has no numbers written on it. You will have to talk to the inspector and ask the exact numbers that your area will want. You do not want to have to remove this tape and start over.

A:  Thank you for your question. Nashua 557 Pro-Grade duct tape is UL listed to provide air-tight seals on class 1 flexible air duct connections. It can also be used for a variety of heavy-duty patch, repair, and bundle applications. For sealing fiberglass insulation, foil tapes such as Nashua FSK or Multi-Purpose Foil Tape are generally recommended. For sealing tar paper or other waterproofing membranes, products such as Nashua Select Flashing tape are generally called for. Nashua would not recommend the 557 for either of the above mentioned uses. Best of luck with your project.

A:  No. Not sure it will be sticky enough

A:  It is very strong other than that I can t say.

A:  Per code you need to use the foil back tape with the sealant attached.

A:  This is real heavy duty tape. I don't see why it wouldn't work on rigid ducting.

A:  Foil tape is what you should use, it is code

A:  Foil tape is less expensive, this the purpose I used it for

A:  Thank you for your inquiry. While there is no UL Code specifically for rigid sheet metal ducts, a better choice would be a UL-Listed Foil Tape such as Nashua 324A which is also available in the Plumbing department at The Home Depot. Best of luck with your project.