Combined with an umbrella policy, it's powerful protection. 

I still vote to do it .It like taking an umbrella with you before you walk out the door on a cloudy day with a forecast of a  chance for rain.

The coverage is often capped at around $300k for homeowners polices, and then an umbrella policy would pick up from there, usually up to $1M or $2M, which covers multiple properties and vehicles for the insured. 

And make sure to account for the following expenses:1) Mortgage2) Mortgage insurance (PMI or MIP) or FHA Risk base3) Property Taxes4) City Taxes5) HOA (Home Owner’s Association) Dues and Fees and Assessments6) Insurance a) Property Hazard Insurance (0.3-0.45%) b) Flood Insurance c) Earthquake Insurance d) Umbrella Insurance7) Vacancy Rate (usually 8% - the equivalent to one month a year, or 5-6% if multifamily and/or if experienced, if not use 8%)8) Utilities (you’ll have these if your tenant is not covering them and/or during vacancy) a) Water § Sewer § Garbage b) Electricity c) Natural Gas d) Propane9) General Maintenance (usually 5%) a) Upkeep § Landscaping b) Snow removal c) Repairs d) New Appliances e) Make ready10) Capital Expenditures (usually 5%, higher is the property is old and obsolete, less if fully rehabbed and all mechanicals and roof are new)11) Property Management (8%, even if you self manage, your time still has value and there might be a time when you'll want to be completely hands off or you'll not be able to do it, vacation, retirement, etc.), including...

Get an umbrella policy. 4.

Are you adding an umbrella policy against additional liabilities?

I agree with the items @David Liu mentioned but add insurance, vacancy, property management (even if self managing because it is work), misc (mostly items divided across all units (bookkeeper, LLC, umbrella coverage, tax man, office expenses, etc) as well as one off items such as utilities due to slab leak.  

@Ravi Sivarathri I agree with the comment on umbrella insurance, it's a great first step to help protect you in the event someone sues you.

Instead, go get an umbrella policy on your homeowners insurance for protection, and you can deduct the exact same expenses on your personal tax return as you can with a LLC.

If you want protection, insurance (umbrella policy), properly structured LLC (just placing in an LLC typically does not suffice), etc. is the more appropriate protection.