I am starting a total renovation.

But I like to have single pours are larger surfaces like the floor, so we will have a truck deliver.In Iowa.

This is an option to consider and many larger banks/credit unions and nationwide mortgage lenders have released new loan programs allowing 2nds, HELOANS and HELOCS.

A real renovation can demand good rent in the right area

I have found some information that might be helpful John.There are government backed programs like Fannie Mae Homestyle Renovation Loan and Freddie Mac Home Possible Renovation Loan, in addition to the FHA 203k loan. 

Lenders may ask for these when determining the post-renovation value.The After Repair Value (ARV) is key to your refinance.

So what if the heloc amount is enough to cover 20% down on investment property and cover renovations.

Each pile of $200k got me 25% down and some money towards renovations on two 4plexes generating $8800/mo instead of one ADU generating $1800. 

I can make larger adjustments in rent when a turnover occurs.

Open a business credit card and do your renovations on that (for things that you cannot get financed with a hard money loan).