Wooden furring strips vs Fiber Glass Z girts for securing continuous thick exterior insulation. Please advice. – GreenBuildingAdvisor

Thank you for your time in advance.

I am building a home with a thick wall. 2 x 6 wood studs, then 7/16″ Zip sheathing, then 3″ Rockwool Comfortboard 80. Then the plan was 1″ wooden furring strips as rain screen/securing rigid mineral wool board/attachment for cladding (using 6″ screws – 1.5″ into the studs), and then predominantly brick veneer (with brick ties attached to the wooden furring strips). 

Builder has never done a wall like this, but we went through multiple videos from Youtube, pictures, and everyone (including his foremen) is on board with the plan. They are worried but think they have a guy who can land the 6″ screws properly within the studs. We discussed marking the studs at the foundation wall, and also using laser line to guide the location of studs and screw placement. The architect is aware of spacing.

I still have concerns regarding their ability to keep a straight wall since using 1″ strips (architect prefers 1″ vs 1.5″ or 2″ for multiple reasons) can cause compression of the rigid mineral wool board, and then the cladding can be wavy. I have seen videos using string lines, and adjusting screws to keep the wall straight during installation, but I am just skeptical since builder has never done this before.

I came across these non metal Z-Girts. These are fiberglass based, and I found three companies – Cladiator Slotted Z, Armatherm Arma-girt, and Exo-composite Z girt. Links below.

Cladiator – Slotted-Z – Fiberglass Z Girt

ArmaGirt Z Girt Cladding Support System | Armatherm

Exo Composite Z Girt – Thermal Bridging Solutions

I got a sample for Cladiator Slotted Z, and the mechanics of it are pretty legitimate. They have a rocket stick which can hold the Comfortboard 80, so basically I can get a 4 inch thick Z girt, install 3 inch Mineral wool, and have 1 inch and a little more space as rain screen. The brick tie can attach directly to the Z girt. It can support claddings upto 61 lbs per sq feet, and my brick would be < 35 lbs per sq feet. It needs small length screws to attach to the studs, which is one of the major reason install is easier.

This will prevent us from having to install longer screws, and use wooden furring strips.

Now, I also saw a video by ACElabs regarding Z girts, and it was from a company Advanced Architectural Products regarding their Greengirt product, which is a composite metal hybrid product.

(7) Selecting Continuous Insulation Z Girts to Meet Today’s Building Codes – YouTube

GreenGirt Optima CMH System | Continuous Insulation Solution

This is a Fiberglass product with steel plates for better holding screws. They have this following table on their website which compares different material Z girts.

Classification of Z-Girts – Continuous Insulation

Here, they cast a less than complimentary picture for the fiberglass Z girts including temporary structural performance, and unavoidable failure at connections.

I reached out to the company to discuss about ability of using brick veneer with their system, and how to create a rain screen (if it will need to be created separately), and waiting to hear back.

Questions:

1. Am I thinking too much and just stick with wooden furring strips?

2. Should I think seriously about the Cladiator Slotted Z as it will make install way easier, and keep wall straight? They have a 12-year warranty, but I am building this home to last generations. Also, I don’t know the costs of this yet. It’s mainly used on commercial buildings, which I assume are built to last a very long time. I am just thinking about it’s ability to last long. I have the samples, and I wanted to have a clearer mind before I bring this to the builder.

Thank you in advance for your time!!