Comparing Air Sealing Tapes
I’d like to offer my input and experience regarding two tapes–Siga and 8067–that I have previously asked about here prior to my use of both products.
As far as performance in terms of adherence to XPS, which was my requirement, the two tapes performed equally well and in fact seemed to be identical in terms of their respective adhesive properties.
I spoke with a Siga rep and asked if he could explain the difference between the two. The main difference I understood from his explanation is that Siga is vapor permeable. 8067 definitely is not as vapor open. The rep explained that 8067 has no backing and will not stick to itself. It most definitely does have a backing and sticks extremely well to itself.
The backing is also offered split. 8067 is offered in 2,3,4,6,9 or 12″ widths. The working temperature ranges are the same as is UV resistance.
In a nutshell, if someone were asking me for recommendations regarding the two my answer would be dependent on whether they need the tape to be vapor permeable or not. That’s really the only viable consideration I can see, and certainly a consideration if your enclosure needs to dry to the exterior. Other than that, the width selections, adhesive quality, and price difference would have me recommending 8067. Siga would have cost me $800 to tape all seams, while I could do it with 3″ 8067 for just over $500.
As a side note, the company I purchased the 8067 from was out of stock of 3″ and offered me 4″ for marginally more. Having that greater area of adhesion makes sense to me.
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Replies
Daniel,
I wonder how much the tapes permeability matters? Considering what a small percentage of any surface would be covered by tape, how much would the vapour movement through assemblies be inhibited by a vapour-barrier tape?
Or looked at it another way: Would an assembly that wasn't getting adequate drying through the materials be helped by the small area of vapour-open tape a the joints?
That's a good point and one I'd be taking into consideration if my enclosure needed to be vapor permeable. Is the surface area of the tape going to be a critical enough factor to justify the added expense of the tape? I'll leave that to the building scientists. It would be good to know. I'll add here that while I'm a strong advocate of the highest quality materials, my wife and I are firmly in the middle to low middle income bracket and while I'm building every bit of my house myself from locally sawn lumber it still isn't easy financially. The savings we enjoyed going with 8067 will be useful elsewhere in the project and it was without any compromise to my specific enclosure.
Daniel, I agree. Saving money on things that don't materially affect the quality of a build is always a good idea. That money can be spent elsewhere in the project, or on something unrelated that makes you both happy. Good luck with your build.
Daniel, I'm at the framing stage of my project and your experience and recommendation is very valuable to me as I'm trying to build on a strict budget and have struggled with if the European tapes are worth the considerable premium. Between your experience and Martin's Backyard tape tests, I feel pretty confident in the 3M 8067 tapes.
pretty much have to call 3m to find out where they keep the stash of 8067. they must keep it in a vault just in case someone gets a wild notion and suddenly wants to tape their sheathing before installing siding.
I got it from Amazon, 2 day shipping a few weeks ago
thx. my builder is at a loss and suggested gorilla tape. Needless to say, I'm skeptical but open to opinions here...
What size? Amazon has 2" and 6" in stock, and say that the 3" will be in stock in a few days.
3m says 3015 is an equivalent so the search is more broad. my question is why is it the same if it is a different product?
Speaking of vapor-permeable tapes, if you haven’t seen it, here’s a short write-up on Huber’s new flashing tape with a 3-perm rating: Vapor-Permeable Flashing Tape.
3m representative reports that 3015 is the same/different(?) for those looking at tape.