Vermiculite Insulation

March 1st, 2016



What Is It?

If you have never seen vermiculite insulating an attic, you may have seen it in potting soil. Vermiculite is a naturally occurring mineral worldwide. When heated rapidly to high temperatures, this crystalline mineral expands into low density, accordion-like, golden brown strands. In fact, its worm-like shape is what gives vermiculite its name. The worms are broken into rectangular chunks about the size of the eraser on the end of a pencil. In addition to being light, vermiculite chunks are also absorbent and fire retardant. These characteristics make it great as an additive, for example to potting soil. It also makes a good insulating material.

Where Was It Used?

Sold under various brand names, such as Zonolite Attic Insulation, the insulation came in big bags. Thousands of homeowners simply opened the bags and poured the vermiculite onto their attic floor and sometimes down exterior walls. It was generally not used in new construction.


When Was It Used?

Worldwide, vermiculite has been used in various industries as long ago as 1920. With the upsurge in home ownership during the baby boom, vermiculite insulation was a popular material in the 1950’s, and continued with the energy crisis into the late 1970’s. In Canada, it was one of the insulating materials allowed under the Canadian Home Insulation Program from about 1976 to the mid-1980’s. The CHIP program provided grants to homeowners to increase insulation levels, reducing energy consumption.

What Is The Problem?

The majority of the vermiculite used worldwide was from a mine in Libby, Montana, owned and operated since 1963 by W.R. Grace. The mine was closed in 1990. As well as being rich in vermiculite, this mine had the misfortune of having a deposit of tremolite, a type of asbestos. When the vermiculite was extracted, some tremolite came in with the mix.
For Canadian use, the raw product from the Libby mine was shipped to Grace subsidiary F. Hyde processing plants in Montreal, St. Thomas, Ajax and Toronto, and Grant Industries in western Canada. At these plants, it was processed and sold as Zonolite.

What Is The Risk?

Asbestos minerals tend to separate into microscopic particles that become airborne and are easily inhaled. People exposed to asbestos in the workplace have developed several types of life-threatening diseases, including lung cancer. Workers in and around the Libby mine developed serious health problems.
Like any hazards, length and intensity of exposure are major factors in the risk of asbestos-related respiratory illness. To assess the risk of asbestos exposure at a house, a sample of the vermiculite would need to be analyzed by a lab. Since most of the vermiculite used in Canada was taken from the Libby mine, the odds are quite good that there is asbestos in the vermiculite in Canadian attics.

The good news is that we don’t live in our attics. In addition, as long as it is undisturbed, neither the asbestos fibers bound up in the vermiculite chunks nor the dust will be released into the air. According to the National Institute for Occupational Safety and Health in the U.S., “Most people who get asbestos-related diseases have been exposed to high levels of asbestos for a long time.” Lastly, most of the time the air in your house flows from the house into the attic, rather than into the house from the attic.
The bottom line is, like most household products that may contain asbestos, and there are many, doing nothing is often the best approach. Naturally, the risk of exposure increases with the amount of time spent in the attic.



If the attic or walls of a house contain vermiculite insulation, leave it alone. Avoid disturbing the material. Do not sweep it or vacuum it up. Do not store belongings in the attic.
If work is planned that involves these areas, for example installing potlights in a room below the attic, send a sample of the vermiculite to a private lab. Send several samples, and use a lab specializing in asbestos analysis. If it is found to contain asbestos, or if you just assume it does, precautions should be taken. The safest approach would be to have the insulation in the affected areas removed by a qualified environmental contractor.


For smaller jobs it may be sufficient to isolate work areas with temporary barriers or enclosures to avoid spreading fibers, use disposable protective clothing, and use proper respiratory protection. An important note – disposable respirators or dust masks are not appropriate for asbestos. Again, it is best to consult a qualified contractor.


Copyright 2015/2016 Carson, Dunlop & Associates Ltd.

Grow Houses

February 1st, 2016

Grow House

Grow Houses


Have you ever wondered why your neighbors never surface from their home, rarely have any garbage to pick up, always have the blinds down or windows covered, come and go at unusual hours and never invite you over for a barbecue? If this is the case, there is a possibility you are living beside a grow house. With an estimated 50,000 grow houses in Canada, there is growing concern about health, fire, safety, and structural implications for home buyers. But what risk is there in owning a grow home?


What is a grow house?


A grow house is a home that has been converted into a marijuana operation. Larger homes in quiet areas with unfinished basements are preferred, although grow houses can exist in any neighborhood.


What are the signs and the risks?


There must be ideal greenhouse conditions for these operations. The electrical system is usually altered to power the hydroponic equipment. Operators may also steal electricity by tapping into the electrical service before it enters the electrical meter, and bring power into the house through a hole in the foundation. Additional circuitry is usually added inside the home to bring electrical power to the equipment, and operators rarely make sure that these alterations meet electrical codes. While these modifications can create a hazardous electrical situation, improvements can be made to ensure the electrical system remains safe for a potential homebuyer. Holes cut in the foundation wall can be repaired as well, but if not done properly, the potential for water leakage remains.


Plants require light, ideal temperature, water and nutrients in order to thrive, and with the heat generated by hydroponic lighting, a significant amount of humidity is produced in the process. While humans, animals, and plants need humidity, too much can cause mold, mildew, and rot to form in the home, especially in or on exterior surfaces. Often, modifications are made to the home to help vent the excess humidity to the outdoors and bring in fresh air from the outside. Fireplaces and chimneys can be used as channels for removing excess moisture. Structural members such as floor and ceiling joists are sometimes cut to accommodate additional ductwork. The structural integrity of the home may be compromised by the combination of cut framing members and high humidity. Signs of high humidity are usually most visible in attic spaces, where the moist air is often dumped. Darkening of attic surfaces is generally a good indicator that mold and mildew are present.


Mold comes in many colors and may be visible and distinct. It can also be very subtle. Surface mold may be the tip of an iceberg, with considerable mold concealed behind the wall. In other cases, the mold is only on the surface. The toughest situation occurs when the mold is not visible. Home inspectors pay particular attention to intersecting walls and ceilings where air circulation is poor or areas that have been chronically damp or wet. The good news is that many grow houses are in operation for less than a year, which may not be enough time for mold to thrive and cause serious structural damage.


Mold Damage


Other clues


Look for painted concrete floors in the basement, and walls that have been painted white to reflect light. Screw holes and patches are often visible in the foundation wall where equipment was mounted above the floor level to avoid any water on the floor. Multiple splices in the plumbing system may be present to nourish the crop. Chemical odors, including fertilizers and pesticides are also used, which can create health hazards through poor indoor air quality.




While it is expected that realtors who are representing sellers or landlords of these properties should make every effort to ensure that all parties are notified of the potential issues, a home inspection can help quantify the severity of these issues. In most cases, with proper clean-up and some repair, these homes can be lived in without concern. Unfortunately, insurance companies are also being very cautious and focusing on reducing loss ratios, not on acquiring business, making it more difficult to get insurance on high risk homes such as grow homes. By exercising good judgment and due diligence in obtaining proper information on the condition of the home, purchasers can rest easy knowing that with a little tender loving care, the home will provide the comfort and security they deserve.



Copyright 2015/2016 Carson, Dunlop & Associates Ltd.

When Things Go Wrong

January 10th, 2016

Expect The Unexpected

When Things Go Wrong

There may come a time that you discover something wrong with the house, and you may be upset or disappointed with your home inspection.


Intermittent Or Concealed Problems

 Some problems can only be discovered by living in a house. They cannot be discovered during the few hours of a home inspection. For example, some shower stalls leak when people are in the shower, but do not leak when you simply turn on the tap. Some roofs and basements only leak when specific conditions exist. Some problems will only be discovered when carpets were lifted, furniture is moved or finishes are removed.


No Clues

 These problems may have existed at the time of the inspection but there were no clues as to their existence. Our inspections are based on the past performance of the house. If there are no clues of a past problem, it is unfair to assume we should foresee a future problem.


We Always Miss Some Minor Things

Some say we are inconsistent because our reports identify some minor problems but not others. The minor problems that are identified were discovered while looking for more significant problems. We note them simply as a courtesy. The intent of the inspection is not to find the $200 problems; it is to find the $2,000 problems. These are the things that affect people’s decisions to purchase.


Contractors’ Advice

The main source of dissatisfaction with home inspectors comes from comments made by contractors. Contractors’ opinions often differ from ours. Don’t be surprised when three roofers all say the roof needs replacement when we said that, with some minor repairs, the roof will last a few more years.


Last Man In Theory

While our advice represents the most prudent thing to do, many contractors are reluctant to undertake these repairs. This is because of the “Last Man In Theory”. The contractor fears that if he is the last person to work on the roof, he will get blamed if the roof leaks, regardless of whether the roof leak is his fault or not. Consequently, he won’t want to do a minor repair with high liability when he could re-roof the entire house for more money and reduce the likelihood of a callback. This is understandable.


Most Recent Advice Is Best

There is more to the “Last Man In Theory”. It suggests that it is human nature for homeowners to believe the last bit of “expert” advice they receive, even if it is contrary to previous advice. As home inspectors, we unfortunately find ourselves in the position of “First Man In” and consequently it is our advice that is often disbelieved.


Why Didn’t We See It

Contractors may say “I can’t believe you had this house inspected, and they didn’t find this problem”. There are several reasons for these apparent oversights:

  1. Conditions During Inspection It is difficult for homeowners to remember the circumstances in the house, at the time of the inspection. Homeowners seldom remember that it was snowing, there was storage everywhere in the basement or that the furnace could not be turned on because the air conditioning was operating, et cetera. It’s impossible for contractors to know what the circumstances were when the inspection was performed.
  1. The Wisdom Of Hindsight When the problem manifests itself, it is very easy to have 20/20 hindsight. Anybody can say that the basement is wet when there is 2 inches of water on the floor. Predicting the problem is a different story.
  1. A Long Look If we spent 1/2 an hour under the kitchen sink or 45 minutes disassembling the furnace, we’d find more problems too. Unfortunately, the inspection would take several days and would cost considerably more.
  1. We’re Generalists We are generalists; we are not specialists. The heating contractor may indeed have more heating expertise than we do.
  1. An Invasive Look Problems often become apparent when carpets or plaster are removed, when fixtures or cabinets are pulled out, and so on. A home inspection is a visual examination. We don’t perform any invasive or destructive tests.


Not Insurance

In conclusion, a home inspection is designed to better your odds. It is not designed to eliminate all risk. For that reason, a home inspection should not be considered an insurance policy. The premium that an insurance company would have to charge for a policy with no deductible, no limit and an indefinite policy period would be considerably more than the fee we charge. It would also not include the value added by the inspection.


Copyright 2015/2016 Carson, Dunlop & Associates Ltd.

YG Video: Home Inspections You Can Rely On

September 27th, 2013

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Are There Rodents In Your Home?

August 15th, 2013

Home Inspection Rodents

Do you have unwanted rodents in your home? Mice and rats are warm blooded rodents who seek shelter during cold months. This should alarm some of you now that Autumn and Winter are just around the corner. Here are some tips on how to tell if they are living in your home, how to prevent rodents from entering your home, and what to do if you suspect them.

Rodent Suspicion

If you notice rodent feces “droppings” in or around your home, you may have rodents inhabiting in your home. Inspect your home for gnaw marks. If you see gnaw marks on packaged foods or sealed garbage bags, it may indicate that rodents may be in your home. Hearing “scratching or squeaking” noises within your walls or ceiling may be another indicator that you might have rodents living in your home.

Rodent Prevention

Assess for any openings, cracks, crevices, or any other entry points that may give rodents access to your home. Interior and exterior examinations should be carried out. If there are openings, seal them properly. Use a water resistant barrier covered with steel so that rodents won’t be able to gnaw through the sealant. Store food in containers properly, rodents harvest and collect food that are not put away correctly. Clean, sweep, vacuum and mop your home since crumbs of food attract these rodents. Dispose of garbage regularly and ensure trash cans are sealed tight.

Rodent Intervention

If you suspect or have seen rodents in your home, contact a pest control and management company in your city. YG Home Inspection Services provides high quality Montreal home inspections. Our goal is to help owners become more aware and knowledgeable about their property. If you need a home inspection, trust our Montreal home inspectors to facilitate the process.