yes thanks Donald--I'm wanting to convert a duplex into one SFH.And I'm just spitballing at this stage, though I'm getting ready to complete one regular renovation in about six weeks and I'm thinking about the next project.

A lot of material but I did my regular licensing online somewhere so I'm used to a bunch of online material that you have to read.

That definitely eliminates the possibility of wood rotting etc due to moisture in the future...  

Most scoop outs end up in the regular garbage dump locale

Wow – that’s not good from a tax perspectiveThe income – and deposit – would all be taxed in the year of receiptThere’s no tax break, no averaging, no postponing, it’s all just regular income"

Actually, I've had my account set up on bigger pockets for a few months now, and I listen to the podcast regularly, but this is really the first time actually introducincing myself and participate in the forums. 

All that hot air and moisture running through the pipe for years is bound to do some damage.

Is paying one-twelfth of my taxes every month along with my regular mortgage payment better or pay the whole taxes in advance will be better??

The reason why I ask is I am at work during regular business hours, so it would be difficult to go there with any kind of regularity.

That does look like it could be the sheet of underlayment that is high and the door has scraped away at it - check the bottom of the door - it will have matching wear marks.If that's not it, then perhaps it was a chemical conflict... certain vinyl and rubber can often be incompatible when moisture is introduced.