With the many stories on the subject shown on TV or heard on the radio, we are savvier than ever when it comes time to acquire a home or a condo. The seller’s declaration, the pyrite test result and the pre-purchase inspection: we take all the means at our disposal to make a prudent and diligent purchase. What if you nevertheless fall on a house that has been used for growing marijuana? Read our article and see the findings of a CMHC study on the subject.

The Canadian Mortgage and Housing Corporation (CMHC) study focused on demystifying two aspects of the nebulous situation of these houses: a better understanding of property damage and the resulting contamination of the environment. Eight home inspectors with the necessary skills to investigate indoor air quality (IAQ) problems, including problems caused by moisture and mold in homes, were invited to participate in the study.

What they found out is quite revealing!

First off, there were obvious traces of the changes made to meet the needs of marijuana growing. In most cases, holes in walls and ceilings where the ventilation equipment was used to remove excess moisture were still clearly visible. The electrical panels had been tampered with and cables and other electrical components were added illegally.

Seven of the twelve houses under study were very contaminated by molds that were visible on walls, ceilings or wood elements. Two houses were moderately contaminated by mold and only one house showed no signs of damage from moisture or mold.

In almost all homes, especially in the basements or in the rooms used for cultivation, the home inspectors detected a musty smell. This unpleasant odor was present in all rooms of the more contaminated houses.

In regards to possible contamination by chemicals, the investigations did not identify the types of chemicals used and to what extent they were. At the time of CMHC’s investigation, all equipment used for cultivation, including any chemical container, had been removed by the police.

As a result of the inspections, each house has been the subject of special recommendations. The investigation reports described the safety and indoor air quality issues. In the majority of cases, the recommended corrective works were important and costly. Only once did they recommend a complete demolition, in the case of a garage that was used to grow marijuana for a long time.

In all of the studied houses, the building inspectors emphasized the need to rip open the basement walls and those of all other rooms used for cultivation and to ensure that there is no mold anywhere throughout the house, its insulation or in the wall cavities after removing the gypsum board. They recommended hiring specifically trained contractors for the elimination of mold. Finally, they recommended blower door tests to check the integrity of the building envelop.

This study highlights, among other things, the importance of opting for experience and competence when it comes to choosing the building inspector who will conduct the pre-purchase inspection of your next home. Our inspectors can perform the complete inspection of your future home and give you a clear picture of the condition of the building.

If you already live in a house and you have doubts about the presence of mold in your home – be it the result of an ancient cannabis culture or not – or the condition of the envelope, we have the service you need. Whether it’s for an air quality test or a blower door test, you can trust the Legault-Dubois specialists.

Source : CMHC

Did you know that…

 …according to the Insurance Bureau of Canada, it would cost an average of $ 41,000 to decontaminate a grow-op house

…the police estimated the number of houses used for growing cannabis in Quebec at 5,00 in 2006

…between 2006 and 2012, the quantity of marijuana plants seized by the Montreal police department increased from 36,000 to 126,000. It is therefore reasonable to think that the number of houses used for growing cannabis have experienced a similar increase

…in the United States, the energy used for growing cannabis indoor is sufficient to meet the demand of more than 1,700,000 households.