Pot Smoke / Grow Odor

Photo by Jeff Stover from Pexels

Questions about our ability to eliminate the odor associated with pot smoke and marijuana grow operations are becoming increasingly common. 

The most common call is from a landlord who just discovered that their tenant is smoking pot in their “non-smoking” rental property.  They are concerned that shockingly pungent odor will be impossible to eliminate and that they will have a difficult time re-renting the property.

Fear not!  In my experience as a landlord (since 2002) the odors from smoking pot are not persistent!  I have had tenants who seemingly smoked pot on a daily basis for years and within a couple days of their moving out, the odor is completely gone.  Unlike cigarette smoke, pot smoke does not seem to “stick” to the walls/ceilings or the HVAC ducts.

Over the years, I have had pot smokers in properties ranging from new condos to hundred year old homes and the result is the same – once they move out, the odor goes away within a day or two. 

I have shared this experience with many landlords and asked them to please call me back if they have a different outcomes, as I know that our BioSweep process will easily eliminate the odor.  To date, I am still waiting for my first call back…

A marijuana grow operation is a much different situation.  In this case, the odor is persistent and will linger long after the plants have been removed. 

If the grow was a couple plants located in finished closet, this is likely a really easy problem to solve.  A general cleaner/degreaser (Simple Green, 409 or similar cleaner), some paper towels and a few minutes to spray and wipe down the walls is usually sufficient.  If they were growing over a long time, it may be necessary to spray, then use a brush to better remove the residue prior to wiping.  Don’t forget to wipe the ceiling and the back of the door!  Leave the door open overnight and reevaluate the odor the next day.

Larger operations always seem to be located in unfinished basements where the odors seem to attach to open wood ceilings and exposed insulation.  In these cases, I don’t know of a better, more efficient way to eliminate the odor than BioSweep.  Eliminating odors from insulation is difficult as you cannot spray/wipe to physically eliminate the odor source.  BioSweep treatment vapors will be able to go everywhere that the odor source molecules went.  With proper time and vapor concentration levels, the source odor molecules will be oxidized, effectively neutralizing the odor forever.

We will typically identify the area of the actual grow, the source of the odor, and position at least one machine in this area.  The treatment vapors from this machine will flow outward, similar to the odor, from this nexus point.  Additional machines are strategically positioned throughout the home to provide sufficient concentration levels of the treatment vapors for the HVAC duct and the remainder of the interior space.

Though a grow operation creates a very persistent odor, the BioSweep process is able to provide a permanent solution.  We are able to guarantee the outcome as long as the property has not been painted since the grow operation created the odor problem.

In 2019, BioSweep of Denver treated a large home (more than 6000 square feet, including an unfinished basement) that was used as a large grow operation with more than 250 plants.  Police were notified by neighbors who could smell the odor from the street.  Once the home was emptied of the plants and related growing equipment, we were able to completely eliminate the odor.

In summary, if your tenant is smoking pot, don’t worry about the odor sticking around and making it difficult to rent to future tenants.  In my experience, the odor will completely disappear.  If they are growing plants in a small, finished/painted area like a closet, you can likely solve the problem by cleaning the surfaces in the grow area and physically removing the odor source material.  Larger grows, especially in large unfinished areas often present a problem that is the time to contact us!

Call Before You Paint!

Many people think that painting the interior of a home is a way to eliminate the smoke odor.  DON’T DO IT!  In about 1/3 of the calls I receive the property owner has painted the interior of the house and it still smell like smoke!  Unfortunately, at this point, I may not be able to solve the problem.

Paint is an imperfect sealer: it keeps our vapors from getting to  the odor source, but the source continues work back through the paint.   The effect is very short term, lasting only a day or so.  When we treat first, the problem is solved – all surfaces, duct work, heater and A/C, the whole interior space of the house.

Everywhere that we can get the BioSweep vapors, we can eliminate the odor.  BioSweep machines convert water vapor
into a mixture of hydrogen peroxide, hydroxyl, and trivalent oxygen (ozone).  At the proper saturation level, this vapor can destroy the odor causing molecules once and for all.