Type N vs Type S on the outer shell

Construction Materials Needed to Build a BrickWood
1

Unknowingly, I made the (hopefully not catastrophic) mistake of using the ubiquitous yellow bag of Quickcrete ''Mortar Mix" as my second coat on the shell of my Mattone Barile Grande. We are doing three coats and the first coat contacting the blanket was type S.

Investigating, the yellow bag is “type N’’ mortar and not ''type S”. The Quickcrete product sheet provided by Quickcrete live chat says type N is different from type S in compressive strength. Where type S has a compressive strength of 1800 psi and type N is 750 psi.

I’m hoping it won’t be a problem given it’s on the shell and it’s not load bearing. I will use type S on the final coat. Quickcrete confirms type S will properly adhere to type N, but would not confirm if I have created an issue.

As an aside, they recommended type S for a final coat when I asked if they recommend surface bonding cement or type S for a final coat. It was unclear to me why.

ACK!

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You are absolutely fine!

You’re basically making a Type S sandwich with a Type N filling, and as Quikrete says, they’ll bond.

Compressive strength is somewhat relevant to the shell, but it’s like the top of a wedding cake. You can put plastic figures up there, or as @BrickWood likes to do, the occasional grandkid. But you’re not supporting a ton of masonry on the shell.

You will be painting or otherwise sealing the stucco when it’s done, and really that’s the critical step.

So, stucco away! You’re good.