Addendum for a flip that has to be extended.

[Sharon Harris]

Hello

I'm wondering if there is an addendum form I can use if the time for a flip has to be extended to include the amount of  money (owed) to investors for every 30 days beyond the original completion date.  If so where can I find such a form or could someone assist with how it should/could be worded for the state of Virginia.

Thanks .