I also discovered some excellent YouTube channels that discuss test material and sample questions, which I watched regularly.

It's the labor details that cost you, NOT the materials. 

Concealment does have a material impact on pay back. 

If development is allowed in the flood fringe then it has to meet certain criteria like it must be a certain elevation above the BFE, at least 1 foot, maybe more depending on the location, and it must be built with certain materials among other things.

I provide tenants with a form to request any improvements and it spells out exactly what they are doing, what material will be used, who will do the work, who pays for it, what happens to it when they leave, etc.

Just like you would do with any non-family contractor working for you:- get them to complete Form W9 for you, as you will need their SSNs- have them provide receipts for materials/supplies and keep those receipts- have a written labor agreement (how much and for what) - pay for materials separately from labor- make all payments electronically rather than cash so you can trace them- pay out of your business account, not personal- issue them 1099s next year if you paid them $600 or more for labor (for the whole year, not per job): https://www.biggerpockets.com/forums/51/topics/1167632-expla... 

Depending on where you are you can change the facade with wood, metal, plants.

My AC guy showed me years ago to check the date the AC was built on the metal tag with the specs.

He was a good guy, totally honest, and I bought a few good buys at tax sales after going through his material.  

A lot of work was delayed due to tenants moving out right before the holidays/new year and unavailability of some materials.