Gannt Chart - Planning for Delays

I own a residential construction company and am currently building a schedule for a project to start in a few weeks.  My scheduling is typically pretty good; however, ever since COVID hit, it's been a wreck.  Ex. I currently have a project that is 2 months behind (9 9-month build schedule).  Due to this, I'm trying to be more realistic about my subs and vendors and plan in A LOT of float time.

What methods do people use to build this much extra time into your Gantt chart?  Ex.  Do you take a 10-day electrical job and just plugin 20 days?  Do you build in extra tasks called "delays" everywhere?

Thanks for your thoughts.