Image Credit: Martin Holladay
More Musings of an Energy Nerd
UPDATED on September 7, 2017 with a new postscript.
In the fall of 2012, I tested the performance of 11 air-sealing tapes by attaching samples to six different substrates mounted on the exterior wall of my woodshed. A month later, I tried to remove the tape samples to determine which tapes were most tenacious. I reported my findings in the April/May 2013 issue of Fine Homebuilding. (The details of the test set-up can be found in that article, “Backyard Tape Test.”)
The tape samples have remained in place for almost a year. Rather than dismantling the components and throwing them away, I recently decided to see which tapes have held up best over the last 10 months.
Here’s the good news: several of the tested tapes are still remarkably tenacious. In fact, a few tapes even seem to have gotten more tenacious as time has passed.
Peeling back the tapes
After trimming the flapping edges of all of the tape samples that hadn’t blown away in the wind, I repeated the tenacity tests that I originally performed in October 2012.
As I wrote in the original article, “I peeled back about 3 inches of each tape to judge its tenacity. Some samples were so tightly attached that it was impossible to pull them back that far. The ratings given in my test report are based on my own judgment of tenacity. … I didn’t use any tools other than my eyes and my bare hands, so this backyard test makes no claims to scientific validity. I rated a tape highly if it was difficult to peel back. … While it seems logical to me to favor tenacious tapes over tapes that don’t hold very well, I’ll leave it to readers to judge whether my criterion was valid.”
The best-performing tapes — the ones that…
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49 Comments
Excellent
Scientific or not, it is an excellent article.
Thank you Martin!
The results are in...
SIGA Tapes rock! http://www.sigatapes.com
SIGA TAPE ROCKS
We had a builder here in Maine build two houses next to each other. With the first house he didn't use any tape and the blower door test was a 1.2 @ ACH 50, not bad. The next house he built he used http://www.SIGAtapes.com to air seal and his blower door test was 0.4 @ ACH 50, very impressive. He used very similar wall details and insulation in both houses. Due to such a tight house (he also used triple pane windows) he has an HRV that he runs continuously on low. He has all Tier III appliances and 3.9 kW of PV. He's on track to be Net Zero with the second house. Very impressive.
a few points could be added...
Did you include the average prices for the tapes ( like $/ft of tape ) somewhere in the previous pages??
Then, this study is also valid on the analyse of the used substrate.
I would've love that you also used TUKtape from canadian technical tape on this study
( which is what is in use on 90%+ of buildings i see around here )
By my personal experience, most acrylic tapes develop a strong bong on Tyvek because of it's fiber like surface ( usually rips a layer of fibers from the HW only a few hours after being applied )
You could've also include peel stick poly + alsphat adhesive membranes
as alot of builders use them to seal in different levels of flashings.
I'll be looking to test the 3M products soon ..i've had some discussion with local tradesman about their new "clear" water/moisture proof peel stick membrane which just happen to look like the tape you tested.
http://www.cttgroup.com/cante
http://www.cttgroup.com/cantech/en/details/135/
this is what i'm talking about ... i don't know about other provinces,
but in Quebec, i'd guess that near 80% ( may be even higher ) of all exterior building tapes installed
are of this product.
The price may explain why ..sells for ~9$ /roll at any local stores.
I have tested 1-2 years of direct sunlight before the plastic peels off from the glue
( which is not bad i'd say )
If used interior, u can still have it stick back after 1-2 years of installation date.
( the acrylic must be responsible for that feat )
It does not do well on EPS and XPS though ...not at all i'd say.
3M and Siga tapes are expensive .. .. i've quickly found from 30 to 70$/roll depending on width
( approx 75ft lenght )
Response to Jin Kazama
Jin,
Here is a link to the Fine Homebuilding article: Backyard Tape Test. The article includes price information on all of the tested tapes. The least expensive tapes (thin housewrap tapes) cost 7 cents a foot. The most expensive (Siga Wigluv) costs 47 cents a foot.
Back in the late 1980s and early 1990s, when housewrap tape was first introduced, it was known as "contractors' tape" here in New England. It was manufactured by DuPont, and it was always red, and everybody called it contractors' tape. Then DuPont renamed it "Tyvek tape," and other manufacturers entered the market.
Meanwhile, over the border in Quebec, everybody called the stuff Tuck tape. Tuck tape is a brand name, although many builders assume that it is a generic name -- as if the tape helps you tuck in the loose elements of your building envelope, I guess. The tape is manufactured by Canadian Technical Tape Ltd. in Montreal.
"Contractors' tape," "housewrap tape," and "Tuck tape" all resemble packing tape used to seal cardboard boxes. These tapes are thin, and they have an acrylic adhesive. I tested three tapes in this category: Dow Weathermate, Venture 1585CW-P2 tape, and Venture 1585HT⁄ W tape. While they work OK on housewrap and foil-faced polyiso, they don't perform very well on XPS, plywood, or OSB.
I would love to have the time and research money to do more tape testing. I did this project on my own time, although I didn't have to pay for the materials out of my own pocket. (Some of the materials were provided by manufacturers, and Taunton picked up the tab for the plywood, OSB, and most of the other substrates. I supplied the housewrap and polyethylene.)
I did some testing of rubberized asphalt peel-and-stick products for a 2001 article I wrote for the Journal of Light Construction. That article is available online: Choosing Flexible Flashings.
I recently rediscovered a large piece of lumber containing many peel-and-stick samples from my 2001 testing. I made a test rig back then to test the products' watertightness. It might be fun to try to peel back those samples -- all of which have been installed for 12 years -- and see if they are still tenacious. Maybe I'll do that, and write a blog about it.
Good to hear that SIGA stays stuck
Martin,
I'm really happy to hear that the Siga Tape Samples that I sent you last year have continued to perform so well. When The Small Planet Workshop http://www.smallplanetworkshop.com imported that first North American order of SIGA Products, it was a step into the unknown. That first shipment was an $18000.00 risk that was based on my feeling that "quality airtightness matters", and that the Passivhaus movement would create an increased need for "quality materials" to support the then staggering 0.60 ACH50 PH standard.
Now it's only a few short years later and the Siga Products have proved themselves exceptionally well in the field. Sales at The Small Planet Workshop of Siga Products are growing every month. Siga has added a US subsidiary, and US logistics center carrying a full load of inventory shipping thru out the continent daily. And... 8 North American employees! -I think it's 8... I can't keep track anymore.
This is all in support of helping our building culture build better buildings that are healthier and consume less energy. Even if luminaries like Dr Joe Lstiburek doubt that climate change is attributable to man made activities, his organization still works tirelessly towards improved building efficiency. Quality long term Air tightness is central to building envelope efficiency.
Now we North Americans have a longer list of quality materials that we can employ to create long term air barriers. This on top of what "you guy's" figured out in the 80's...
Here's a short video clip of the first SIGA AIR TIGHTNESS WORKSHOP FOR PROFESSIONALS in North America. It was held in Seattle Wa in late 2010. The attendee's are most of the board of Passive House Northwest http://www.phnw.org, and the Northwest Eco Building Guild http://www.ecobuilding.org. -The tall guy leading the workshop, Patrick Haacke, whom you met in https://www.greenbuildingadvisor.com/blogs/dept/musings/one-air-barrier-or-two -is now part of the Management Team of the company. At the end of the video is Michael Brogle who now heads up the North American effort.
Here is the video of what a SIGA AIRTIGHTNESS WORKSHOP FOR PROFESSIONALS looks like. http://youtu.be/yzPkfLbLk3M. We hold them about 4 times per year thru out the Pacific Northwest. The next one will be in late October or early September. They are free and contain loads of useful information.
Artistic tape design
Martin,
I think you should be complimented on your abstract tape design. Did you design it yourself or did you have help on the artful placement?
Reponse to Lucy Foxworth
Lucy,
I am lucky enough to live in a rural area. We have no requirements for design professionals, engineers, registered contractors, or design review board approval. We just do things the old fashioned way in Vermont.
Response to Albert Rooks
Albert,
Thanks for your helpful comments, and for your reminder that Siga Sicrall is intended for interior use.
You are absolutely right that it's important to check with the manufacturer's recommendations before selecting a tape for any particular application.
Use the right tape for the right application.
Martin,
Just to clarify...
The Siga Sicrall held best to your XPS which is great. But readers should check with a SIGA Dealer before ordering for their first application. It's an easy call to make and SIGA puts a lot of effort into making sure who answers the phone can help you choose the right tape or membrane for the application.
I'm pointing this out because it's not always apparent what to use. In this case, you found that Sicrall stuck better than anything to XPS. Thats fine for an interior application but probably not so good for exterior XPS. Sicrall has a paper backing and even though it's done well for 10 months, it's not recommended to be used on the exterior layers. For that application Wigluv 60 is the recommended tape since it's formulated to be used in exterior applications and is expected to perform for decades.
They both have the same adhesive and what helps them stick is that they have loads of it. The Sicrall was probably harder to pull off then the Wigluv because the heavy paper backing is stiffer and wouldn't pull back on itself like the flexible Wigluv 60 backing would.
In any case... Call your supplier to check the application before you order for the first time. There are different tapes designed for different applications and it matters which one you choose. To reach The Small Planet Workshop it's: 1-855-FOR-SIGA
Looking at the photo, I would
Looking at the photo, I would think that the tapes up under the eaves would fare much better than the tapes down below. They were exposed to less sun and rain, though the same temperatures and possibly less wind.
Response to Brian Godfrey
Brian,
Fair enough. I'll admit it wasn't a scientific test.
If anyone wants to either fund a better research project, or set up a better rig in their back yard, I'll be the first to trumpet their results or findings.
Good Info
Thanks for doing this test. I've been very curious about the longer term results of taped gaps and wanted to see something like this before buying some very expensive tape.
After all this what do you think about tape vs caulk for sealing plywood sheathing (butted edges) as an air and vapor control layer? I can see pros and cons for each. Tape is likely faster to apply but caulk is less expensive and gets into crevices.
Response to Karl Overn
Karl,
Vertical sheathing seams occur over a stud; caulk might work at this location. However, most horizontal seams are unsupported by framing. To seal these horizontal seams, I would definitely choose tape over caulk.
The best available tapes are impressive. No one knows if they will last 100 years, of course. But we can be pretty sure that caulk won't hold up that long, especially if the seam being sealed is stressed by expansion and contraction of materials due to changes in temperature and humidity.
to confirm XPS
I can concur that XPS presents a hard problem for tape. I've
got a few places with Tyvek tape or Weathermate on XPS, and what
seems to happen after a while is that some chemical interaction
with the acrylic adhesive "bubbles" the XPS a little bit right
underneath. If left alone it doesn't seem to weaken any further
or peel off, just sits a little higher than when I applied it.
I can also smoosh down the raised part and it seems to return to
the original surface contour for the most part. But I'm only
a year-plus into this particular observation, so I can't say what
things will be like in 12 years.
All the relevant joints aren't under any stress and don't appear
to have actually compromised their seals, so maybe it's not a
problem as long as the joints are somewhat sheltered from
direct weather.
_H*
We've got Siga on XPS since 2010.
Hobbit,
So far our test apications have the Siga Wigluv bond still impressively strong on the XPS samples. Note that these samples have stayed indoors and have not been subject to the exterior conditions of the Pacific Northwest (aka: damp rainy hell).
At least we can note that they are not self-destructive.
Tape test
I'm a general contractor in the Pacific Northwest and I specialize in rot repair. The efficacy of adhesives exposed to the weather is wonderful information to have. I wonder how effective adhesives are in real world use. How do asphalt based tapes react with PVC I wonder. Or how do the tapes do when permeability is an issue.
Building envelopes need seals, vents and drains. A key element in envelope design is its ability to persevere in the variety of the states of water and the ability to resist the ability of fungus to thrive in adverse environments. The environment beneath the exterior shell has its own unique habitat. Water, air, spores and a food source in this space should never be considered or taught as a complete envelope system so contractors like me can reap the rewards of a multi billion dollar problem in the construction industry.
Under what circumstance should a method a, method b or a modified method a be used to flash openings? In a rain screen application where do the concepts of a seal, vent and drain prove most effective and why? When and where do envelopes fail and how does the changing states of water encourage or inhibit fungal growth?
In the residential construction and repair arena the flow of information on the most effective methods and materials needs more development. Asphalt melts PVC, sealing moisture where a drain or a vent is needed rots wood. Window openings need seals, vents and drains. The various states of water need to be addressed in the building envelope as a whole. Building inspectors and envelope installers need concise, accurate information on how building envelopes function so damage can be alleviated.
Response to Todd Noice
Todd,
Your broad statement, "Asphalt melts PVC," is unsupported by the facts.
Rubberized asphalt membranes are compatible with the type of hard vinyl (unplasticized vinyl) used for most window flanges. Some rubberized asphalt membranes aren't compatible with soft vinyl (plasticized vinyl), but there aren't many opportunities for these products to come in contact with each other.
For more information, see:
http://www.protectowrap.com/static-content/pdf/letters/letter-chemical_compatible.pdf
http://forums.jlconline.com/forums/showthread.php?45927-Peel-and-stick-flashing-compatibility
http://www.homeadvisor.com/rfs/smpros/printArticle.jsp?edOID=13630
PVC compatibility with asphalt
In every instance I have seen asphalt based tapes applied on vinyl window flanges over a period of time I have seen that it softened and discolored the vinyl. See also: http://www.na.graceconstruction.com/custom/flashings/downloads/26324_Guide-B.pdf
Grace Vycor Self-Adhered Flashings are not compatible with plasticized polyvinyl chloride (flexible PVC). Certain metal window applications with integral nail fin may have specific limitations. Contact window manufacturer for specific application instructions required when using
a bituminous-based flashing.
I use Hydroflash - the advantages of acrylic tapes make them the best choice for me. I'm more concerned about providing the proper drains, seals and vents in the envelope and cladding. A comprehensive independent study of the Vaproshield and HydroGap screen systems would be helpful.
Has anyone tested tapes on fiberglass backed polyiso?
Just wondering if the fiberglass material makes a difference in what tape to use. It is obviously a different surface than foil.
Response to Clay Whitenack
Clay,
I didn't perform any tests on fiberglass-faced polyiso. But I've been very impressed with Siga Wigluv -- so that would be my first choice of tape for that purpose.
Fiberglass Polyiso tape test
Just in case anyone is interested, I performed my own un-scientific test on fiberglass-faced polyiso. I got a roll of Siga Wigluv, Owens Corning JointSealR, 3M All Weather Flashing tape 8067 and 3M Construction Seaming Tape 8087.
I was disappointed with the Siga Wigluv, since I had heard great things about it. The tape didn't seem to have good hold on fiberglass, and actually peeled off pretty easily by just rubbing a finger against the edge of the tape. The tape is pretty thick, and I think that hurts it because it is more likely to get damaged when something rubs against it.
The best performing tape, from what I could tell, was the 3M Construction Sealing Tape. It held to the fiberglass very well, and trying to peel the tape off pulled off the fiberglass with it. It is also very thin, which means its less likely for something to brush against it and peel it back along the edge.
Response to Clay Whitenack
Clay,
Thanks very much for sharing the results of the test. This type of information sharing helps us all.
I'm curious: how long did you leave the tape in place until you tried to remove the samples? (It's possible that the Siga Wigluv might have improved its bond over time -- but that is just speculation.)
Based on your findings, I would certainly choose the 3M tape if I needed to tape fiberglass-faced polyiso. Again, thanks.
Response to Martin Holladay
I wondered about that too, Martin. It hit me that I may have tried to peel the tape too soon, so I let it sit for a few days and tried again. I couldn't tell that it had strengthened its bond over time. Now, it has been pretty cold around here lately, and the sample block has been sitting at the construction site. I'm not sure if that has anything to do with it, but the other tapes have been exposed to the same temperatures as well. Maybe the Siga needs the temperatures to warm up a bit before it really starts to bond up tight. I guess I could take the sample block home with me and run it under a hair dryer for a few minutes.
Change the results
Hi all,
I need to update my "scientific findings" and change my recommendations.
Yes, in the "lab", the 3M Sealing Tape performed the best. However, out in the field, it didn't live up to the expectations. The tape didn't seem to do well in actual use. There are several ideas as to why, but the best reason we could come up with is that the tape is very thin and not flexible. When applied to the seam, sometimes there was a little give between the two sheets of foam, and that wiggle room allowed the tape to initial stick to the foam and then detach, and once it was detached the fiberglass came off onto the tape, and once that happened there was no stickiness left on the tape.
Sorry for the misinformation.
Width of plywood tape
What have people found is needed width wise for a successful and durable bond? I was planning to use zip tape (3.75” wide) to seal seams in plywood as my exterior air barrier. However considering the upgrade to Siga Wigluv which is a 10% increase in cost however it’s 2.25” wide... is this a net downgrade or upgrade?
Scott,
I have been using the
Scott,
I have been using the 2.25" Wigluv to seal Advantech flooring and it works very well. I think Siga recommends at least 5/8" coverage on each side of a wood substrate so the 2.25" is plenty. Compared to Zip, it is less prone to air gaps/creases, and it is vapor open. For those looking to perform backwoods tape testing, I believe Siga tapes take 24 hours to reach maximum strength and Zip takes 72 hours.
Jonathan
What is that a picture of?
Jonathon
Thanks Jonathon! Made my mind up. I have a moderate level of understanding of where and when vapour permeable and impermeable materials should be used but don’t see why a 2-1/4” strip of tape should benefit to being vapour open?
Response to Malcolm Taylor
Malcolm,
Jonathan Lawrence has posted that photo before. I'm pretty sure that it's a photo of a flat roof, adjoining a collection of sloped roofs.
Malcolm,
Martin is correct.
Malcolm,
Martin is correct. The only difference between this picture and the one I posted before is this one has more tape! Another day, another roll of tape. It is a panoramic shot, so it looks stranger than it does in person.
The flat roof was incorporated to accommodate solar panels that would not be visible from the street. I am facing south in the picture.
Scott - It depends on if you
Scott - It depends on if you want to limit vapor diffusion or not. I like to give assemblies a path to dry whenever possible and appropriate, so I tend to err on the side of vapor open.
If I’m understanding you correct you are saying that if you had to choose between a 2” and a 4” tape, you’d go with the 2” to seal joints in sheathing. And between a 2 and a 3 you still would take the 2 because it seals off less of the substrate, allowing it to dry quicker, while still being wide enough to seal the air gap in the joint.
Correct me if I’m wrong.
Thanks!
Kevin,
Are you asking Jonathan Lawrence this question? If so, you should be aware that his comment was posted more than a year ago -- so he may not be monitoring this thread anymore.
Thanks Eric.
I just couldn't place it. I thought maybe a skateboard park!
Hi Martin,
Do you have an answer to Kevin Kevin's question? It appears Jonathan Lawrence is off-line.... Thanks!!!!
Here's his question again:
If I’m understanding you correct you are saying that if you had to choose between a 2” and a 4” tape, you’d go with the 2” to seal joints in sheathing. And between a 2 and a 3 you still would take the 2 because it seals off less of the substrate, allowing it to dry quicker, while still being wide enough to seal the air gap in the joint.
Correct me if I’m wrong.
Thanks!
M.O.,
I think that Kevin was accurately reflecting Jonathan Lawrence's opinion -- but I can't be sure, because I'm not Jonathan Lawrence.
Narrower tape allows for more drying from sheathing -- in some but not all cases. (If we're talking about roof sheathing, drying may not matter -- because most roofing is vapor-impermeable). Wider tape sticks better. My own take: I wouldn't worry too much about the reduction in drying rate from the small area of the tape. After all, moisture can migrate sideways by wicking. Wider tape definitely sticks better.
All,
I just saw my name on the recent comments list during my daily GBA check so here is my response. I have used many different tapes on this job and my conclusion is they all stick and stick well. I think 2 1/4" tape (insert name of manufacturer of your choice) is fine for plywood sheathing. However, if using Zip sheathing I think you need to use Zip tape to keep your warranty. Btw, the flat roof in the picture above now has 31 solar panels on it that generated 46 kWh of energy today in sunny New Jersey.
Jonathan,
"that generated 46 kWh of energy today in sunny New Jersey"
Nice!
Thanks Malcolm. Attached are a couple of shots of the panels. I am still aiming to be net zero including the EV's.
Great location for access and maintenance.
I apologize if this was explicitly addressed elsewhere, but what tape would be recommended for interior use in sealing the exposed edges of foil faced polyiso anywhere that you wanted to prevent water absorption? Thinking to seal the exposed edges along the bottom of board insulating basement & crawlspace walls. Does it need to be foil, or would Polyken Shadowlastic work, or is that overkill?
Thank you! Stay healthy.
Eric
Eric,
If you are wrapping tape around the edge of a piece of foil-faced polyiso, then you need a tape that sticks well to foil facing. Fortunately, foil is one of the easiest surfaces to tape to -- most construction tapes stick very well to foil, including housewrap tapes, Polyken Shadowlastic, and 3M All Weather Flashing tape.
I would choose among available tapes by price, frankly.
Thank you sir!
All these products are so confusing, is there any clearing house? Here's just one example. The specs for popular self-adhered air barrier products are all over the map for air leakage. From .04 cfm/sf to .00004 cfm/sf. Does it make any difference at those numbers? One vendor says it does and his product is much better because of it. Or are they all airtight enough and it’s just marketing? I suspect workmanship and detailing are way more critical than which barrier gets used?
Also, is it necessary to tape plywood seams prior to adhering the membrane like Blueskin VP100 to get PH level ACH50’s?
Qofmiwok,
Q. "The specs for popular self-adhered air barrier products are all over the map for air leakage, from .04 cfm/sf to .00004 cfm/sf. Does it make any difference at those numbers?"
A. For more information on this topic, see "Is OSB Airtight?" A rating in cfm per square foot isn't meaningful unless you know the test pressure that led to the measurement. According to the article I just linked to, "Section 5.4.3.1.3 ('Acceptable Materials and Assemblies') of ASHRAE 90.1, a model building code for commercial buildings, states that the following 'continuous air barrier materials' are 'acceptable': 'Materials that have an air permeance not exceeding 0.004 cfm/ft2 under a pressure differential of 0.3 in. w.g. (1.57 psf) (0.02 L/s.m2 @ 75 Pa) when tested in accordance with ASTM E 2178.' ”
If you accept the ASHRAE 90.1 standard, then you want a self-adhered air barrier material that, when tested at a pressure differential of 0.3 inch water gauge (equal to 75 Pascals), leaks at a rate that does not exceed 0.004 cfm/ft2.
Q. "Is it necessary to tape plywood seams prior to adhering the membrane like Blueskin VP100 to get PH level ACH50?"
A. No. But you can easily fail the Passivhaus airtightness standard, even with well installed Blueskin VP100, if your house has significant leaks in the envelope that the Blueskin doesn't cover.
Yes they are all listing the 75 Pascal measurement. The question is, is .00004 better than .004? I'd think not.
Qofmiwok,
Q. "Is .00004 better than .004?"
A. Yes, but the difference isn't meaningful for this application.
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