What Does a Grow Op Home Look Like? | Fairbairn Home Inspections

A Grow Op Can Destroy a Home’s Electrical and Structure.

Marijuana grow op (MGOs) are common in the BC lower mainland, however this crime has diminished in popularity lately (most occurred in the 1990’s). They are incredibly destructive – a home may be filled with mold and hazardous wiring. If you’re buying a property in BC, this is must-read information… buying into a grow op home could spell financial disaster.

Here are a few things to look for:

1. Unusual Marks and Patches

Marijuana cultivation generates an enormous amount of hot, humid air, and the growers will look for the easiest way to vent it. Closet ceilings provide a discrete passage for ductwork. Look for circular/square patches in ceilings:

  • There may be circular cut marks between rooms, or in the floors above crawlspaces.
  • Grow lights are hung from above, so look for patterns of small nail/screw repairs in ceilings.
  • Look for circular patterns on floors – pots often leave a ring-like stain. The floor may have been painted to cover up the stains.
  • If the grow op took place in the crawlspace, check the bottom of the joists for nail holes.
  • Check for fresh paint around windows where sills may have been damaged.
  • Check for remains of red tuck tape around crawlspace and attic vents, and bits of foil (used to reflect heat from the grow lights)

A great trick: Take a flashlight and lay it sideways on a wall or ceiling – this casts a shadow on any imperfections and allows you to see past repairs. I have used this technique in thousands of homes and it works very well for seeing the wall’s history.

2. Modified electrical

Growing plants indoors requires a huge amount of power – and the operators don’t want anyone to notice. Look for evidence of tampering next to the electrical meter. Also look for high-amperage breakers (in the main panel) that don’t appear to have a purpose. If you see several 40-amp breakers, and there’s only one kitchen in the home, be careful.

At one inspection in Surrey we noticed 4-5 high voltage (240V) range type receptacles in the basement ceiling. There are not many reasons to have that much power running to a basement! (4 ovens, perhaps?)

3. Modified Fireplaces

Look for evidence of tampering with fireplaces – these provide an excellent exhaust option and are often rusty, damaged or have broken glass or missing fire logs. There may be tuck-tape or duct-tape around the flue. In some renovated grow-ops the fireplaces have been completely drywalled over to hide the damage.

4. Attic Mold

Marijuana grow-op Attic Mold

Look for staining and signs of moisture in the attic. Attics usually suffer badly – black mold and, in many cases, rotting wood, can be found. If an attic has been remediated (mold removed professionally by a contractor), there are usually still signs visible. Remediation usually leaves a white or green residue that is easily seen.

Extreme mold will show up as branch-like marks, even on the trusses. Thin, winding patterns on 2x4s and plywood indicate extreme moisture conditions.

In a particularly bad ex grow op the plywood or OSB sheathing may have been damaged to the point of collapse. In one building we inspected in East Vancouver, there were mushrooms growing out of the remnants of the attic sheathing!

5. Modified Ventilation and Ducting

Leftover ducting from a grow-op in Langleygrow-op ducting in attic

Check the attic and roof for added ventilation. A few roof vents or a turbine vent is normal; six turbine vents is not. Also, check for staining around the exterior soffits. In many grow homes there is rust-colored staining on the soffits due to the metal in the roofing nails “bleeding” through the eaves. As part of our home inspections we check the soffits carefully. Ventilation issues and condensation can usually be predicted before even entering the attic area.

6. Construction Debris

Look for electrical tape, ducting, masks, gloves, loose wiring and bags of insulation, particularly in the attic and crawlspace. Several times, we have found trash bags full of ducting and soil still in the garage. Criminals can be just like the rest of us – forgetful!

7. Unusually High Security

Grow-Operations were originally more likely to be on dead-end streets, cul-de-sacs, and forested areas with a lot of privacy. However, newer operations can occur anywhere, even in condos and townhomes with close neighbours.

Check the front door for signs of forced entry – the police may have broken down the door to get in.

Look for unusually high amounts of security such as bars on windows, security cameras and triple-locked doors.

But what about the seller’s PDS (Property Disclosure Form)? Doesn’t it require owners to disclose the existence of a past grow op?

While it’s true that there is a section on the form requiring the sellers of a property to disclose any latent defects or important history of the home, there are a few problems with relying on this form for accurate information:

  • The owner may be deceptive.
  • The owner may not be aware of the issue.
  • The form wording may be a loophole – many forms ask the seller if they are “aware” which may be open to interpretation.
  • They are difficult to enforce in court. If you need to sue, it may be impossible to prove that a seller was actually aware of an issue.

Do Your Due Diligence!

Have a quality, professional home inspection performed, every time you purchase a home. Your professional inspector is trained in finding problems, and can save you from potentially expensive mistakes. While an inspection can’t guarantee an MGO will be uncovered, and most SOPs (Standards of Practice) do not require reporting mold conditions, the inspector may notice signs of faulty wiring or unsafe tampering with heating equipment, for example.

Updated July 12/2016

Added more information on attic remediation residue, as well as information on drywall side-lighting tricks. Added detail to smaller sections.

Update: grow op Chart added:

How to tell if a home has been a grow-op

About the Author DavidFairbairn

Author David Fairbairn is a certified, licensed home inspector serving Vancouver and the Lower Mainland. He has been featured in the media and has contributed to "24" Newspaper, and Global TV. He has spent years working with residential and commercial building projects, and holds a Power Engineering License in BC. Why not give him a call for your next Home Inspection? Call 604 395-2795 or email david@fairbairninspections.com today!

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