I'm thinking about getting large landscape stones to create a barrier. 

Now consider it may be more money but also consider the fact that if there is a claim you can count on your insurance to do what it was created to do which is to insure.

@Jake Parks - If you're pooling money together and providing a return for people/there is an expectation of profit for someone else and that other party is not involved in the decision making/management of the deal , then you are creating a security and the answer to your question is a resounding yes.The big thing you have in your favor with partnering up with family and friends is that you have a relationship with these people already and that's the biggest thing that the SEC is looking for.

Money created out of thin air!)

Marvin is one of the top window mfr for residential. https://blog.marvin.com/2017/06/27/vinyl-vs-aluminum-vs-fiberglass-not-all-materials-are-created-equal/https://www.energy.gov/energysaver/window-types-and-technologies

We were looking to create a promissory note in which would allow us to buy into each other's personal investment property after the refinance stage.

That would KILL your IRA and create huge tax penalties.There is a retirement plan based structure know as a Rollover as Business Startup that allows you to take existing retirement funds and use them to capitalize a business in which you are directly involved. 

This would not only allow me to acquire the property without paying interest on a loan, but it would also create a more solid business relationship with an already great mentor in the industry.Has anyone attempted something similar to this? 

The added fees, and compliance regulations have almost eliminated small independent investors, and financial institutions from doing mortgages, and in return have actually created worse situations for many consumers.

So yes, the carpet was due for a replacement even without flooding.Often flooding and molds creates it's own odors.