ZIP tape rolling quality checks
I’d like to preface this by saying that there are no builders in our area who are willing to even attempt to build to a high standard in terms of air sealing. I have a good relationship with my builder and I’m not putting this on here to bash him. He has been willing to try a bunch of new things that are just not done in my area, primarily attempting to get an ACH50 of less than 1 and pursing external insulation and building with higher quality flangeless windows. I’m very thankful I’ve found him and that he’s willing to make an attempt on this stuff.
With that for context, I’m looking at our house progress and I’m seeing some things that I’m not sure about. If this is an issue, I firmly believe it’s not from a position of lethargy or malice or anything like that, but rather from a position of just not having the experience to know what to do. My question is how to resolve it going forward (if it’s an issue at all).
So here is a video of how the ZIP tape has been rolled. On the parts that aren’t adhered now can I just roll it again or does it need to be pulled off (is that even possible because there are places that are adhered well) and redone. Maybe a new roll needs to go on? Maybe I need to roll it and then liquid flash it to make sure?
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If there are the roll marks, that is all you really can ask for. Where it bit more care is needed is above windows where you have horizontal ZIP. There you need very good adhesion to prevent fishmouths.
As for the staples, they are not an issue. They simply don't effect the efficiency of the WRB and since it goes into solid wood, they don't leak any air.
The one you do want to get right is the bottom of the wall. I don't know what the plan is for that but you do want to seal that up properly. The sill gasket is a good start but you need to connect the ZIP itself to the foundation.
Zip tape is both pressure-sensitive and time-sensitive. Once installed, it takes about three days to fully set. Maybe you can get a bit more adhesion by rolling or squeegeeing after three days but I doubt it would have much effect.
Go to one of the box stores and get a roller. You can just get one of those couple inch wide rollers in the vinyl flooring section if you want. Try rolling the area you're worried about.
When the plywood is offset like you're showing. There could be something under it forcing it up but most of the time if the end of the zip plywood soaks in a tiny bit of water expands a little. Then the thickness is different. I've had them do this just in storage.
Now when they're offset and you roll it it's obviously not going to push down correctly and adhere right. You have to roll it on the high side and on the low side separately. So try to roll the low side by yourself and see if it sticks better. Unless it got water stuck under it should stick again.
Staples are okay but I like galvanized ring shanks myself. I've seen too many plain steel nails corrode from the glue in the plywood and have barely anything left when I pull plywood off.
I'm picky on my own projects I do seal over the nail heads. A beer and an hour usually covers it :)
Looks like rolling was just incomplete.
If the tape is fresh, and there isn't anything coating the exposed tape adhesive or the sheathing in the unrolled areas that would prevent adhesion (dust, water, etc.), it's definitely possible to try rolling it and getting it to stick. If the weather is warm, there's an even better chance of success.
Huber's official stance is that there's no particular reason to cover overdriven fasteners, but there's nothing wrong with hitting them with ZIP Liquid Flash or Prosoco Fast Flash for a belt-and-suspenders approach. Dab a little on each, and strike them with a Bondo spreader or similar.