I am in the process of purchasing a rehab that has been smoked in for the past 20 years. What are some of the most effective ways of removing the smell to achieve showroom quality short of tearing out every piece of drywall.

I should note that we are planning to remove all the carpets and flooring and replace them. We are also planning to paint every room.

Kills is your friend!! Kilz will seal all of the surfaces you paint. My first rental had gloss paint on all of the walls and I thought it would be so easy to just wash down the walls... DAYS of washing and the coffee colored water coming off of the already washed walls I was told about Kilz. Sprayed the entire house and what a difference! Below is link to introduce you to an ozone treatment. I am NOT recommending any company or product in the article, just a pretty good overview.

https://www.washingtonpost.com/lifestyle/home/its-tough-to-get-rid-of-cigarette-smells-but-an-ozone-treatment-can-do-it/2018/11/11/e0d64dfa-dedc-11e8-85df-7a6b4d25cfbb_story.html?noredirect=on&utm_term=.7f52158d27c3

Lots of Kilz sealer/primer and two coats of a good eggshell paint. Also replace carpet and padding. If there are hardwood floors sand, stain, and seal. 

Hi G. Emerson Zollos,

I'm in the same boat with a duplex, where one of the units was occupied seems to be a chain smoker - the walls, ceiling & floor are just completely saturated with cigarette tar/smoke.

While I haven't begun rehabbing the 2nd unit, I've been doing my homework on the best way to tackle this project and what seems to be the most effective treatment that I've found so far, short of ripping out the drywall/plaster & lathe, I've been reading that using a TSP solution with warm water very effective in removing the "gunk" so to speak - once the walls have been thoroughly cleaned with TSP, use an oil-based primer (Killz) to seal the walls and then apply a few coats of paint. I've also read about people using an ozone generator to help remove the smell as well.

Priming/painting over the tar/smoke is not a viable solution in such situations, as it will just bleed through the new paint.  

You're off to a good start with planning the removal of all the fabrics/carpets & padding that contain the tar/smoke.  You'll also want to look into having the HVAC system/ductwork thoroughly cleaned out as well.

Best of luck and keep us updated on your progress!

Just gotta say i love this forum. . . the responses are so fast and super helpful. Thanks for the advice, ill definitely coat and paint. . . hopefully i can do without a full ozone treatment. I'll post a bit more if I find any other solid options.

We did a house that was very heavily smoked in. You could see where anything was hanging on the walls, etc. Washed it twice with TSP. This is important no matter what you're going to paint it with as you need to remove the tar residue so the paint can adhere.

The we painted it with the oil based Kilz (not the latex Kilz 2) Then we painted it with our usual top coat paints.

Every piece of flooring was replaced. All the lighting fixtures were either thoroughly cleaned or replaced.

All cabinets were washed inside and out with TSP and the exteriors painted.

Shelving was removed, cleaned, painted and reinstalled.

The HVAC system was replaced (because it didn't work), we did not replace the ducting and it seemed ok.

Overall, it came out well and the smoke smell went away.

This house took a lot of elbow grease but it cash flows well.

I just did this to a 4 apartment building.  

1.  We removed the carpet and padding, mopped the plywood underfloor, then sealed it with KILZ.

2. We scrubbed the walls, TSP worked well, then painted with Kilz. The pulled out the ceilings that were acoustic and replaced the tiles, and scrubbed and sprayed with Kilz, then repainted the drywalled ceilings.

3.  We scrubbed the cabinets, countertops, tiles, and linoleum flooring, about 3 times with Mr. Clean.

We thought we were done.  The smell was gone.  But then we turned on the air conditioner.  House stunk immediately!

4.  We had the HVAC system professionally cleaned and odor remover blocks placed in the vents. Looking at the over the stove vents, it was better for us to replace the whole unit for $80 than to clean them.

Note:  Our apartment was lived in by druggies, so we had no lights left, they were recycled along with the plumbing pipes.  But if we had wooden fans, we probably would have just replaced them.  Anything porous needs to be sealed or trashed.

Two thirds distilled vinegar, one third Dawn. never fails.

Once you remove the carpet and paint the ceiling and walls, the smell will be gone. Killz is a stain blocker, not a smell blocker. The new paint and carpet removal should do the trick.

Some tips on TSP: the box probably has some recommended ratio, like however many tablespoons in a gallon of water. Ignore that and just keep dumping TSP in the water until no more will dissolve.

The TSP solution will be pretty alkaline... wear gloves (the kind for washing dishes is fine), and long sleeves. Think hard about wearing safety glasses, too, especially if you're working on the ceiling.

In some areas, all you can easily get is "TSP substitute". If you're close to the border, or have a buddy in another state, see if you or they can smuggle you in some real TSP.

You can pour the TSP solution down the drain to dispose it. If you do that, run some more water down the drain with it - it won't really hurt the pipes, but diluting it helps the creek and the river not be so foamy.

I haven't had to deal with smoke, but I did need to clean some pretty greasy/oily walls in a kitchen before painting, and the TSP seemed to do a good job.