Growing pains: cannabis cultivation risks

Canada’s Senate is weighing in on weed this week. What it decides could have big implications for homeowners. The senators are voting on a proposed amendment to Bill C-45 that would permit provinces the option to ban home cultivation of recreational cannabis in their jurisdictions.

Already Quebec and Manitoba plan to prohibit the controversial practice of home growing in their province which could set them up for a legal battle with the federal government if Bill-C45 passes without that opt-out amendment.

Legal or not, home cultivation does present risks which many of our members are by now familiar.

Growing pot indoors is risky because the cannabis plant is demanding of its gardeners. It’s not as simple as growing your beefsteak  tomatoes on the back porch.

In a climate like BC’s, cannabis requires special care and attention with a lot of shelter, warmth, humidity, artificial light, and water. To make it grow fully and productively, it also requires a considerable amount of nutrients, and to counter pests such as spiders, mites and caterpillars, some growers rely on pesticides.

Based on the law as it stands, a person won’t need training or a license to legally grow recreational cannabis at home, so the degree of safety will depend on the individual grower and how skilled, knowledgeable and careful they are.

Consider the number of drivers who rush a yellow light, go over the speed limit or appear to be impaired.  Having a license does not guarantee a person will act responsibly.

Physical Risks

The government is assuming that four or five cannabis plants will not leave as much residual evidence in a home as a large grow-op. But as Realtors are well aware, there are hazards common to both situations.

Mold: Many home grows do not have proper ventilation to dispel excess heat and moisture, which spurs mold growth—a  risk to human health.

Carbon dioxide: Growers may try to increase their plants rate of growth by harnessing carbon dioxide (CO₂) which speeds up photosynthesis. But the amounts of CO₂ can reach levels that displace the oxygen level in the home, and cause a serious health risk to humans and pets.

Chemicals: In grow homes, fertilizers, herbicides and pesticides in high concentrations are often found in unsecured containers or worse, spilled on the floor or dumped in open garbage cans.

Fire and electrocution: Some home growers will hook up wires themselves and fiddle around with the circuit board to set up electrical bypasses without knowing what they’re doing.  Combine the amount of water needed for cannabis plants, with faulty electrical hookups, and it’s a recipe for disaster.

Even after the grow-up  equipment is removed, home buyers and renters may be subject to the residual risks from faulty electrical setup, mold and exposure to leftover chemicals.

Lingering signs of cannabis

  • Modified ductwork that doesn’t seem to make sense
  • Circular holes in floor joists or roof trusses from venting (look for holes that have been patched)
  • Chunks of brickwork on the exterior that have been replaced
  • Stains on floors caused by containers that sat unmoved for long periods of time, or stains in laundry tubs
  • Modified wiring and electrical panel. Sometimes, live wires can be in the insulation
  • New plumbing for water supply and drains
  • Foundations and concrete walls cored or breached to get wiring around the hydro meter
  • Warped/rotted wooden structures due to excessive moisture

Remediating a home that was used to grow cannabis is certainly do-able and although there is currently no province-wide standard for remediation and inspection of such homes, each Fraser Valley municipality has its own protocols for remediation.

We will look at those protocols in the in the coming days. In the meanwhile, check out our new micro-site Safe Grow Homes to educate both buyers and sellers of the risks of home-grown cannabis.

 Helpful Links:

Municipal procedures for disclosing property history of cannabis or drugs

REA – Material Latent Defects