Nice but I know they didn't lay down any underlayment to protect from the cement right beneath it.

No way to know for sure until you get some estimates or think of a plan to fix it yourself by either going over it with some cement or rebuilding it with concrete or wood

Has anyone used the portable self storage units rather than building a building on a cement pad. 

The home is a bilevel and the first floor has a near perfect cement floor.

When the windy season (or rain, if we get any in a given year) arrives in autumn, I take it down; the tarp generally lasts 2-3 years before needing replacement.Anyway, I'd like to replace that with a robust permanent structure, which I'm envisioning as being a similar structure as the tarp thing; two corners attached to 2x4s in the eaves, the other two out in the yard attached to a 2x4 or 4x4 set of wood posts, fastened securely to the cement surface in the yard. 

By profession I am a genral dentist in Washington, DC.

The following is some side information I want to share so if you have enough info please skip to the link.Back then it had a hole in the roof and holes drywall in a couple of units, which has been recently fixed.Other issues include: outdated kitchen(all 4 units), missing carpet in living room areas, rotted doors, needs repainted stucco on exterior walls and new paint interior as well, updated ceiling fans, and ceiling paint, updated Water heater and HVAC, replaced glass windows, repair door frames, overrun landscaping and trash, broken cement drivewayUnknown information: water/plumbing issues, electrical issues as it was winterized when I looked inside the home.Upgrades I want to add include: Security lighting/system,up-to-date kitchen, update fireplace molding, paint parking areas,update all entryway door and closets, carpets to laminate flooring, examine windows and doors for gaps to reduce heat loss, if need be examine plumbing electrical and heating ducts.Analysis:Quad plex in same neighborhood with same stucco construction and year  sold 4 months prior for 232K w/ no new updates just clean livable conditions. 2 Quadplexes that are brick construction and older  models but have been updated to 2015 and currently pending contracts for 315K.What numbers am i missing.

Next time you visit your dentist ask if he will give you a discount if you don't have him use novocaine.

Oh yeah, he also saved my wife @$7000 in dental work done by his excellent Cancun dentist.

The subflooring is cement.