The insurance adjuster will have reimbursed you for the value of the roof (sometimes minus some depreciation) - depending on your coverage.Roofer will be quoting based on replacement cost. 

I know it will depend on how much renovation takes place and the state of the rental market, but on average is it a month, two months, or ?

That value could be zero if you think that your project management time/expertise is just as valuable as the land... that will all depend on whether his undeveloped land is worth $5K or $50K or $500K!

I  mean I buy vacant land.. and other non cash flow deals.but I have a way to value add ( build on them) or a pretty strong idea that path of progress is going to run into us.really depends.. and I agree building wealth at 100 to 200 a month at a time.. you take on a ton of debt for very little actual return..

We recently added 3 AirBNB vacation rentals in Costa Rica to our investment portfolio, and my advice is to consider:1 - all potential expenses (it is higher than you might think for AirBNB, depending on location, upscale or not, outside management, etc), especially start-up furnishing expenses2 - high and low seasons because occupancy may not be consistent throughout the year. 

There are a few possibilities that may benefit you depending on what your overall goal is.

@Darrell Carter In this situation, it depends.

I think its wholly dependent upon precisely where you live and updated for property unique conditions.

Depending on whether you're ready to buy and hold or if you need to build up cash, your path may be different.

Keep in mind, depending on your state's landlord-tenant laws (and judges) these may not be evictable offenses.