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Community and Q&A

Liquid Flashing Products

happycanuck | Posted in General Questions on

Hello all, hoping someone can point me in the right direction. In the Toronto area, Ontario. I need a prosoco/zip type STPE liquid flashing product to start sealing up gaps and rough openings in the cottage I’m in the process of self building.

Struggling to find anything easily obtainable at a reasonable price that is like prosoco fast flash here – the closest locally available equivalents I’ve dug up are the Sika Hyflex 150 (I can get via Amazon easily, about $27/sausage) and the tremco dymonic 100 (local supply store keeps it, about $13/sausage).

Are either of these a good or suitable substitute for prosoco type liquid flash? I know the tremco is poly rather than STPE ( I believe STPE is the more proven way to go), the Sika I think maybe STPE but despite reading all the docs am unsure. They describe it as a single ingredient elastomeric so it sounds like it might be what I want.

Thanks in advance any advice is very much appreciated.

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  1. Expert Member
    Michael Maines | | #1

    Is there a reason you aren't using Prosoco or Zip LiquidFlash?

    1. happycanuck | | #2

      Michael, in answer yes - I just can't find anywhere to buy them in Canada. Theres 2 Canadian websites that mail order the prosoco, but they're both about $35-$40/sausage from memory, and the shipping was horrendous like $100 :(

      Thus, I started trying to find more readily available alternatives.

  2. happycanuck | | #3

    A better phrasing of my messily worded question I guess, is "are either tremco dymonic 100 or Sika hyflex 150 suitable alternatives to prosoco fast flash"? :)

  3. Danan_S | | #4

    Henry Air-Bloc Liquid Flash, which is STPE, is apparently distributed in Canada

    In fact, Scarborough ON appears to be Canadian HQ (Global HQ is in California), so you could probably drive or even take the bus there to talk to them :)

    I didn't use it on my house, but I had a good experience with their Blueskin VP100 adhesive membrane, FWIW.

  4. Expert Member
    Akos | | #5

    If you are using ZIP/OSB/CDX, I would do most of the sealing with their tape and only use liquid flash for the problematic joints (ie foundation to Zip or head flashing above windows/doors).

    My local lumber yard (Downtown Lumber) stocks Zip liquid flash, I'm sure the larger yards outside of the city would also carry it or be able to order it in. Not cheap though, more reason to only use it where absolutely needed.

    1. AC200 | | #16

      I'm not an expert, but I totally second what Akos said. I have Zip, three types of Siga, 3m 8067 tape as well zip liquid flash on my build. Siga is the most expensive but I think its the best. It's in my window sill pans and seals between foundation and sheathing. My sliding door installers used 3M 8067 and Zip is used everywhere else on the sheathing. I think Siga is the best followed by 3M and then Zip. The 6" zip is a royal pain because it doesn't have a split backing.

      A couple tubes of liquid flash were used for difficult to tape areas. I would use Siga tape if it were in budget. If not, 3m 8067 and only liquid flash as required.

  5. happycanuck | | #6

    Thanks Dan for the suggestion, I'll contact them. I did find the air bloc lf product, but again couldn't find anyone locally or even online to actually buy it from.

    Despite the widespread use of liquid flashing in the US and all those Matt risinger videos I've been watching, all the products seem incredibly rare here :s

    1. Danan_S | | #7

      I didn't use any liquid flash, but I taped sheathing joints and went over those with an fully adhered membrane. My builder used Protecto Wrap flashing on the window frames. On the foundation-sheathing gap, first I caulked it, then primed and applied Siga Wigluv tape. I'm sure liquid flash would have worked even better than those approaches, but liquid wasn't as cost effective or easy to install for a beginner like me.

      Matt Risinger makes everything look really easy, but he's a high end custom builder, not a DIY air sealer.

  6. jberks | | #8

    I'm also in Toronto, and scoff at the difficulty of getting Prosoco products.

    I'm a big fan of PU's like dymonic 100 and sikaflex. I know you're preferably looking for a STPE, but dymonic 100 is still high performance and I enjoy it's durability (I haven't had the chance to test an STPE, so what do I know). The only thing I don't like about dymonic 100 is It's thickness. Usually that's good for controlling your beads and tooling joints, but it's hard on your hands to pump and trowel flat if you're doing a lot of it. I find sikaflex is a bit thinner so I can trowel it easier.


  7. user-1116814560 | | #9

    I hate to break it everyone but prosocco MAKES the liquid flash for zip any perception u have re viscosity and durability will probably vanish if blinded. As for Tremco they make a roller grade and a trowel of their gc250 which IS Dymonic 100 with different viscosity gc 25o comes in 5 g buckets that cover 100 sq feet for $200 or 2$ a sf. How many sf will a 20 oz tube zip liquid at $34 cover ?

  8. Ryan_SLC | | #10

    Perm rating is different between the two spec sheets for both their flashing liquids. Also, UV exposure is 180 days on Zip and 12 months on Prosoco.

    Since the spec sheet is what is used to prove something, I really doubt everyone's claim they are the same.

    Benjamin Obdyke's tape and liquid flash is what I'm using, knowing before hand of Zip and Prosoco.

    1. Patrick_OSullivan | | #11


      Total Solids: Zip - 99%, Prosoco - 99%
      VOC content: Zip - 30 g/L maximum, Prosoco - 30 g/L maximum
      Hardness, Shore A: Zip - 35-45, Prosoco - 35-45
      Tensile Strength: Zip - >150 psi, Prosoco - >150 psi
      Elongation at Break: Zip - > 350%, Prosoco - > 350%
      Water Vapor Transmission: Zip - 21 perms, Prosoco - 21 perms

  9. Ryan_SLC | | #12

    The link you put up says exactly what I said.

    Spec sheet says 12 months exposure on Prosoco 12 months expsoure.
    Zip 180 days.

    Zip spec sheet and website are at odds on perm.
    Perm is is 21 on prosoco.
    Perm on Zips website ( says 23-24.

    Spec sheets do align with mil application.

    So off the website, not the same. On spec, you are right...except that's a hugely significant difference in exposure.

    So you sir, are most right and I am 25% right :D

    We should lay it to rest. I just had prosoco shipped from Amazon directly from prosoco. Came from Kansas. If someone confirms Zip liquid flash ships from Kansas, I'll give in :D

    1. Chris_in_NC | | #14

      Packaging might not be at the same plants. Huber might get bulk supply and do their own cartridge fill and packaging, instead of having a private-labeled product manufactured directly at a Prosoco plant, for example.

      After using both Fast Flash and Liquid Flash, they gun and tool slightly differently, so I think they are slightly different formulations, even if possibly made by the same company. The composition on the SDS for both products seems to back that up, as the percentage ranges are not identical.
      The Huber SDS has a supplier address, and the Prosoco SDS has a manufacturer address, which clearly implies that Huber does not manufacture their own product.

  10. Ryan_SLC | | #13

    I will say, Benjamin Obdyke does fair better on some parts of the spec sheet vs the other two.

  11. AC200 | | #15

    I'm surprised that Zip is not available at any local lumber yards listed on the Hueber website. I got all my Zip, tape, avantech sub floor and liquid flash from Turkstra. They carry the full line. I think the large tubes were about $65 cdn and sausage were about $40 cdn.

    Unless you are using very large quantities, I would buy based on performance and ease of application with cost as secondary factor. Liquid flash is messy to use and clean up.

    I've found that lumber yards (not Home Depot) and supply houses are much better places to purchase construction materials and are usually cheaper. Amazon is probably the worst place, IMO, as its usually resellers selling stuff they bought from supply houses.

  12. Ryan_SLC | | #17

    Amazon is probably the very best place to buy, if the manufacture is the seller and shipper. No one will have it closer to the shelf life date than that. Prosoco shipped my sausages directly to me from their factory. No shelf sitting at a lumber yard.

    Another example, HD and others are 1 month out for SureSill. While I didn't end up using and returned, HD said one month delivery, delivered in 3 days using amazon.

    It does have it's place.

    1. AC200 | | #18

      Not in Canada where the OP and me are. In the US, I agree

      1. Ryan_SLC | | #19


        A small price. Canada is wonderful. Wife and I are considering another home there.

        Take care

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