Plywood tape…
I would like to “compare and contrast” some different tapes for use on the rough surface of exterior grade plywood – for air sealing purposes.
The tapes under my consideration at the moment are:
1. Grace Vycor Plus
2. Berry Plastics Barricade OptiFlash 732-20
3. Mastic tape
4. Siga Rissan
All four tapes claim “agressive” adhesion.
Adhesion is one thing, conforming to the slightly irregular surface of plywood is another.
I only have direct experience using mastic tape but I can imagine that any of the first three will probably adhere and conform well.
The “Rissan” is a mystery.
A Siga brochure indicates that it bonds to “wood”.
It also says that some difficult substrates require priming with “Dockskin”.
I wonder if plywood is a difficult substrate?
Anybody ever tried Siga Rissan on plywood?
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Replies
First, I would look at Venture 1585CW-P2. It bonds well to plywood, even in cold weather. It lacks the same properties as the mastic based tapes, but is much more economical. I see where you're going with the Vycor, Optiflash, etc... Any tape with a bit of "give", like an asphaltic (vycor) or buytle (Optiflash) base would seem to fill in the irregular surface of the plywood. But here are some questions to consider when looking at this type of situation. How airtight can you reasonably expect the building to be? Is the plywood the primary air barrier, and are you using a wall assembly that requires plywood? The reason I ask is that OSB, and the HUBER system both provide a smoother surface if permeability isn't an issue. Are you concerned about long term adhesion, or potential air leakage through the gaps between the tape and the plywood? This could be an interesting thread as it raises a number of questions regarding how far we need to go to airseal a building.
Lucas,
the guy to ask re: SIGA is albert rooks/small planet workshop.
i think for wood to wood, the sicrall might be the right tape, not the rissan. depends on application. dockskin might be a good suggestion - in europe, OSB tends to be much smoother (sanded, i think) and it's not here in the states, so a little prep work makes getting the tape airtight a little easier.
also, what about 3M's 8067?
Hi Lucas,
You said exterior plywood. I want to make sure that the right product is considered. Rissan 60 is for interior applications, not exterior. If this is at the exterior layer, Wigluv 60 is the recommended product. It will stick to and conform to Plywood just fine. For either Rissan or Wigluv, plywood is not an issue at all. None of the US "woods" need a primer. In the US manual (current addition) it refers to some "woods" needing the dockskin primer. This is only for the soft wood fiber boards that they have in Europe. We have nothing like this in the US.
Full disclosure: I am the SIGA Importer, so I have a strong bias. I brought it over to support the people in my region who are building to the Passive House Requirements. That said, your question about how tight do we need to go... My answer is 0.6ACH for my crowd. How to do that while maintaing exterior permeability is why I got into SIGA. The Wigluv 60 at the exterior layer is still permeable, and more so, than the plywood that you'd put it on.
You can see the specs, some US based descriptions, and/or send me a mail at http://www.smallplanetworkshop.com... or call if that's helpful...
Best Regards,
Albert Rooks
I'm going to use plywood as my air barrier, and don't see why one shouldn't first use the APA, or airtight plywood approach (to twist "ADA" a tad). I am not familiar w/ tapes on plywood, but I would think Tremco acoustical underneath the ply would outlast the tape. I'll do both methods. OSB always seems a bit "oily" to me, and I can't imagine tape sticking to it as well as to plywood, either. Another reason to avoid OSB?
seems like as long as you have a backing behind it, some type of caulk like sealant would work best with any expansion contraction, and it will stick
if you were to use something like grace vycor, you could always run staples into it to help it stay where it should. also using one of the approved primers on the wood before hand woudn't hurt.
the zip system basically has a pre-applied primer on it that works with the tape
taking a clue from the liquid applied WRBs, they use a mesh tape over joints and a mastic like substance as a filler before applying the liquid wrb. i'm sure if there was a tape that would work, they approve that too but they don't
the large membrane peel and stick WRB sheets would work if money is no object
Thanks for all the responses.
Personally, I intend to build as "tight" as possible.
<0.6ACH50 would be great, however I am not interested in attaining PH certification.
I believe "ultra-tight" doesn't have to be complicated if enough thought is put into devising a simple air sealing strategy.
In addition to avoiding complex geometry, simple to me also means affordable and not too time consuming.
In my case, detailing the plywood sheathing for air-tightness seems like a good way to achieve these goals... but there is still some strategizing to be done.
The flashing tapes seem to offer a lot in terms of the performance qualities I'm looking for but are possibly too expensive to use large quantities...
Maybe a hybrid strategy of using drywall gaskets and tape would be more cost effective...
John Klingel, maybe "APA" is a good way to approach this...
Albert, thanks for the information.
The "Wigluv" tape...
How would you describe it as compared to a mastic-like tape?
Is it "gooey"?
Is it flexible?
How does it's cost compare to the Grace Vycor which I would buy for something like $30/75' roll.
Edit to say: Yes, the application would be exterior grade plywood
Lucas, Here is a link to the price list. The site says you have to buy a full box.
http://www.smallplanetworkshop.com/storage/SPW%20SIGA%20NEW%20PL%201.21.pdf
John
Lucas,
I would add the 3M Flashing Tape to your list. It's thinner and more flexible than Vycor, but seems to stick even better to rough surfaces, especially in cold weather.
http://www.shop3m.com/3m-all-weather-flashing-tape-8067-bcsvcx6cxs.html
In case anyone reading this thread hasn't seen it, it's worth pointing out that a section of the following blog discusses tapes for plywood or OSB: Air-Sealing Tapes and Gaskets.
(I just added Jesse's suggestion about the 3M tape. Thanks, Jesse.)
Jesse, thanks for the suggestion.
And John, thanks for the price information.
The back of my envelope is telling me that Siga is in the back seat in terms of cost...
I'm a bit surprised.
Is the higher cost due to the fact that it's imported?
Like buying parts for a VW?
Any reason why you're not looking at either the Huber Zip system or Grace's enV system?
Response to Lucas:
The Wigluv works equally as well on plywood and OSB. It's not like either the 3M or Grace products. It's quite different from anything seen here in the US prior. It's extremely flexible and sticks like you wouldn't believe. The longevity target is 50 years in application.
What makes it so different is that it is a Vapor Diffusive exterior air sealing tape with a perm rating of 1.2, is UV resistant and can be left exposed for 12 months uncovered. It has no rubber and no solvents or VOC's. That means it will not "embrittle" or have adhesion failure as solvent based adhesives do.
All of that may seem rather extreme for the US, but it's a product made for the central European market where air-tight construction is "old hat" and products like this have been perfected. The market over there has moved from basic rubber/solvent tapes that seal and keep the water out, to specialized tapes that attempt to match the permeability of the layer that they are applied to. In that market, wall sections are typically an increasing diffusion open gradient to the exterior. That means the exterior tape needs to balance two potential perm levels: 0.6 to.7 for when it's applied to sheet stock (plywood/OSB) or the higher perm ratings of the higher quality housewraps (Siga Majvest 68 US Perms). The 1.2 perms is an ok balance and has proven reliable in it's ability to manufacture.
So... Yeah. All of that with no solvents or VOC's (it's water dispersed). It costs a little more as higher quality products often do. I know it seems a little extreme for some of us here. If you don't feel that you need that level of product... Save a few bucks. As always, cheaper products abound.
Best of luck,
Albert.
Response to John,
Thanks for posting the price list. It is always nice to ship full boxes (they ship easier), but not realistic. I had updated the web site that less than box is possible, but not the download price list yet. Thanks for the catch.
So... any quantity is ok.
Also, as luck would have it, I just shipped 2 rolls (yes... only 2 rolls) of wigluv 60 to complete a Passive House Project in wisconsin. There are pictures and video of it applied to OSB...
http://www.naturalhomemagazine.com/blogs/blog.aspx?blogid=3180&tag=newenhouse
Great project.
Best,
Albert.
Albert thanks again for the information.
I have always thought the Euros made "air tight" construction look like "old hat".
I think the Euros are way ahead of us North Americans in a lot of ways...
As you suggest, I think it shows in their more "evolved" building products.
Aaron, I have looked at the Zip system.
I know less about the enV system...
My general impressions are that they would not be a good fit for my project.
I want to stick to more conventional building materials as much as possible.
Gaining access to enough material for either system would be more difficult for me than just using plywood.
1/2" exterior grade plywood has a good permeability rating for an air barrier material in my climate.
I'm not sure I want yet another learning curve at this point...
Slightly on or off topic..... has Huber ever answered the question... as to Zip OSB in that....
Is Zip OSB sheathing, standard crappy OSB or is it made as well as their Advantech sheathings or is it something in between?
AJ,
Yes, they have answered the question. According to Michael Pyle, a Huber manager, Zip System panels are more water-resistant than ordinary OSB or AdvanTech OSB because they contain a “medium-density, phenolic-impregnated, kraft paper overlay” — in other words, an outer layer of plastic-impregnated paper.
More about Zip System sheathing can be found here: All About Water-Resistive Barriers.
Outer layer is of course in good shape.
I should have stated that my concern is for moisture coming from the inside. Condensation.
I am assuming Advantech uses glues or whatever internally that are much more water resistant than typical OSB.
Does Zip sheathing also use better internal glues like Advantech or just rely on the outer layer for outer only water protection and no inner water protection?
Thanks so far for commenting Martin
My understanding of Huber ZIP and AdvanTech...
According to our sealant supplier, they haven't been able to find anything that effectively works for gluing down AdvanTech because of the wax that's impregnated on the outer layer. We've tried Franklin and PL polyurethane and neither sticks long term. That being said, when the ZIP system was introduced, they hosted a breakfast at our yard with the rep. My first question was what happens when a nail is over driven. He claimed that as long as it didn't go through more just the outer layer it would be fine, the inner make up is very similar to AdvanTech. That being said, personally I would probably tape over any over driven nails. If installing on a customers house, I wouldn't dare use anything other that their tape, unless I had something in writing from Huber saying the tape I wanted to use would work. The Grace enV system is a liquid applied WRB, can be sprayed or rolled. IIRC gaps bigger than 1/4" need fiberglass mesh tape. To me it seems like the most bullet proof system out there.
Jesse,
The 3M tape...
3M says it uses an acrylic adhesive.
Do you know how flexible this tape remains after it is applied?
I've got some in my house that is still exposed and it's still completely flexible a year later, but that's not much of a test.
Blake Bilyeu in OR had a good slide at his PH presentation this year of his test (180MB file!): http://passivehouse.us/passiveHouse/2010_Passive_House_Conference_Presentations,_November_5_files/2010%20Conference-Rue%20Evans-Blake%20Bilyeu.pdf
Jesse, thanks for the reference.
The 3M tape isn't at all like I imagined it.
It looks like it might be just the thing though.
Lots of other interesting things in that presentation too...
I like the gable end attic access...
Lucas, I agree, they did a great job with that house.
I'd love to hear a bit more about how they upgraded their Therma-Tru entry doors with multi-point locks and thermally broken sill to get a high performance affordable door. That's a very good trick.
would have been better had they put that 3m sample tape on a seam, and on something not laying flat
joing movement and somewhat gravity are the enemies
and grace enV or similar would be nice but you need to be next to a lumber yard that will work with ya for a do-it-yourselfer as buying whole pallets of the various components isn't practical