They don’t care about the house; they are only there to make money. Marihuana grow operations (MGOs) are operated with little or no regard to the immediate or future safety of the occupants or neighbours and with absolutely no consideration for the home’s value. Residential and commercial buildings are often used so criminals avoid damage to their own property.

When there is a police intervention and criminal investigation local health and local government officials attend. The property is assessed for physical damage to walls, floors and ceilings from possible electrical bypass, water damage, ducting holes, chemical spills and moulds. The end of the remediation process usually concludes when the local authority no longer objects to the occupancy of the building and it issues an occupancy permit.

Grow operators often disconnect the combustion stacks from the heating, ventilation and air conditioning (HVAC) system and hot water tanks for the purpose of ventilating the grow op, that’s dangerous because these appliances have the potential to discharge combustion gases into the building. Grow ops are power monsters and tampering with the electrical system tampering can lead to possible fires or electrocution. Chemicals are used in MGO’s and likely there is chemical contamination on surfaces, a result of mixing and spraying fertilizers and pesticides in and around the crop areas, presenting a health risk.

After the administrative actions take place it’s time for the physical cleanup. When the authorities are involved this process is stringently monitored. Permits are taken, the air quality of the home assessed and all work inspected. All grow op related materials remaining behind, including plant pots, soil, fans, lights, cutting, tools and general rubbish, are removed and disposed of. Chemicals, both in their original containers and in mixed solutions, must be properly disposed of. Next, it’s time to gut the affected area down to the bare floor and studs. All floor coverings, drywall, vapour barriers, and insulation are considered contaminated so they all go.

There is an estimated 20,000 active MGO’s in British Columbia. They range in size from a few plants to houses of plants. They can be big business and cause big damage to a home. One thing is certain; it’s the homeowner that is left responsible footing the bill.

For tips on how to spot a grow op in your neighborhood click here.

(Photo: Hugh Cairns) Remediating a marijuana grow op includes removal of mould-stricken materials and disinfectant scrub of affected surfaces. Seen as red paint in this photo, the exposed surfaces are completely sprayed treated with a mould inhibitor.

Hugh Cairns welcomes your questions, comments and suggestions. Contact him through www.subject2homeinspections.com or interiorinfrared.com.