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Concrete Porch poured next to ZIP Wall Sheathing, How to Flash Properly

BGreen0002 | Posted in GBA Pro Help on


We are currently building a new home, Climate Zone 5.  The builder poured the concrete porch right up against the ZIP Wall Sheathing.  From what I see, I don’t think this looks right, and definitely requires a little more “protection”. 

We are planning to install the Vinyl siding, using aluminum flashing at the base of the ZIP wall.  Also, the porch was poured with positive drainage, and slopes away from the home.  The concrete porch is under a very large overhang, so any water that actually gets on to the porch will be minimal.  (We have had some major downpours this past month, and I can confirm this). 

Should we leave the “gap” as is, and install the metal flashing at the base using ZIP tape, or should we use ZIP tape or liquid tape to seal the gap first, then the aluminum flashing?  

I cannot decide which is better, let it dry out if need be or seal it completely.  

Also, I want to protect the side of the concrete ledge that pours out, keep the water draining out and away, if that makes sense?


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  1. BirchwoodBill | | #1

    Have the builder read the Huber instructions that the ZIP needs 1/2 inch from concrete. Did they add a capillary break between the ZIP and concrete?

    1. BGreen0002 | | #2

      From the foundation to the ZIP wall, yes. This concrete porch was poured later, up to the ZIP wall.

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