(250) 871-8638 ghelpard@tsolum.com

Grow Op & Drug Lab Environmental Testings


Marijuana grow operations and drug houses are common in BC. Many home buyers unknowingly purchase homes that were used as drug houses in the past and still contain toxic mold or other contaminants. Landlords are often the victim of growers and require environmental testing before the house can be occupied again. We specialize in former marijuana grow-op investigations, testing and cleaning. We can provide the information necessary for buyers, owners and residents of these buildings. All services are 100% confidential.

Marijuana (Grow Op):

There are particular signs to look out for that indicate you might be living in a former marijuana grow-op.
Marijuana grow-ops can cause lasting damage inside homes due to the moisture from marijuana plants, which create mould and spores in walls, ceilings and floors, according to Wilson. The air inside the homes can also endanger residents’ health. Those who run grow-ops also often re-wire homes to bypass an expensive hydro bill that can cost about $1,500 per month. Patchy electrical work also makes a fire 40 times more likely in the home, according to a City of Ottawa staff report released in November.

Here are 12 physical signs your home may once have housed a marijuana grow operation:

  • 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
  • Brown stains in soffits (the exposed undersurface of a roof eave) from the grow-op venting to the outside, or brand-new soffits.
  • In the winter, bald spots without snow on the roof from heat loss.
  • Stains on basement floors from pots that sat there for long periods of time, or stains in laundry tubs.
  • Modified wiring and electrical panel. Sometimes live wires can still 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 (staircases, floors and window cases) due to moisture damage.
  • Toxic moulds form/spread poisonous spores in the open, within wall cavities, inside window frames, ventilation systems and attic spaces.
  • A musty smell or, in the case of meth labs, odour that smells like cat urine.


If there are no obvious physical signs that indicate you live in a former grow-op, there are three things you can do to double-check:


  • Check for any electrical changes with BCHydro.
  • Get an indoor air quality test.
  • Check if any permits were drawn for that address.
  • Condensation in windows.
  • No activity coming to and from home.
  • A pungent odour.
  • In the winter, no snow on the roof.

About Us


We are a safety-conscious, Canadian owned and operated multidisciplinary consulting firm focusing on ecologically-based service. We offer complete range of services including all aspects of indoor air quality; hazardous and occupational hygiene services.

Contact Us


800A 8th Street
Courtenay, BC V9N 1N8
Phone: (250) 871-8638


Phone: (250) 585-2261
Fax: (250) 585-3374
2213 Northfield Rd.
Nanaimo, BC  V9S 3C3


Phone: (250) 590-8638
Fax: (250) 590-8628
907 Esquimalt Rd.
Esquimalt, BC  V9A 3M7