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Liquid-applied flashing across dissimilar materials?

Can a liquid-applied flashing product like Zip System Liquid Flash or Prosoco Fast Flash span a gap between different building materials? The particular situation I can think of would be the application of liquid flashing to the inside surfaces of a window buck and out onto the face of exterior rigid insulation like foil faced polyiso. Seems like adhesion and flexibility could be suspect.

Asked by Brian C
Posted Jul 11, 2014 7:36 AM ET
Edited Jul 11, 2014 7:58 AM ET


2 Answers

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You should direct your question to the technical help department of the manufacturer of the product you plan to use -- or, better yet, you should consult installation instructions that most manufacturers post online.

For an overview of the topic, see this GBA article: Housewrap in a Can: Liquid-Applied WRBs. The article takes an in-depth look at products from Sto and DuPont. The manufacturers of these products require the use of fiberglass tape (and a special liquid-applied product) to span large cracks and dissimilar materials.

Answered by Martin Holladay, GBA Advisor
Posted Jul 11, 2014 7:55 AM ET


Cracks and gaps need flexible membranes for crossing and are never easy to do but not as difficult as trying to add peanut butter to jelly instead of jelly to peanut butter...
lunch time here ;)

Answered by aj builder, Upstate NY Zone 6a
Posted Jul 11, 2014 1:37 PM ET

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