Defiantly like people are saying use the kilz or the zinsser 123 I used that on last house that was smoker.

If the applicant submitted an application, with the appropriate fee and was qualified to rent your home, legally you'd be obligated to rent to them with their Section 8 voucher.However, if you have other policies like no pets, no smokers or no more and X vehicles in the driveway, you can deny tenancy to Section 8 voucher holders who don't qualify because of pets/smoking/parking concerns.It's important to not be discriminatory, but you can also protect your investment by being vigilant in your tenant screening avoiding future headaches.

I have had more problems with tenants who are closet smokers than with pet tenants.

I'm a smoker.

but don't worry, it's safely locked down.2) Smell-- figure out the cause, is it a horrible smoker,  bad carpet, or mold? 

Does it make a difference if I put smokers upstairs and non-smokers downstairs.

@Michael NahmDon't approve a smoker.

I try to employ strict screening criteria for applicants, including verified income 3x over rent, two positive landlord references, satisfactory credit situation (score above ~600 with no negative patterns established), no smokers, and no large dogs.

---------RENTAL CRITERIAGENERAL REQUIREMENTS1.Each adult (18 years or older) must complete an application to rent and background check authorization form.2.Each applicant must provide a valid government issued picture ID at time of application. 3.Each applicant must qualify individually or together with a co-applicant as a household. 4.An application fee of$40 per application must be paid prior to processing the application.5.Occupancy is based on the number of bedrooms per unit.Maximum occupancy is two persons per bedroom.6.No Pets - no pets allowed on the premises.7.No Smoking - no smoking allowed on the premises.We will not rent to smokers.8.No Drugs - no illegal drugs are allowed on the premises.We will not rent to illegal drug users.9.No Firearms - firearms are not allowed openly on the premises.If a firearm is owned, it must be safely stored.10.We conduct full background checks.

She's a smoker and that bugs neighbors.