Pyrite - Fools Gold

Pyrite is a naturally occurring mineral found in many geological rock formations. If its concentration is sufficiently high and the crushed stone is exposed to humidity the pyrite can begin a chemical transformation that causes the material to swell and expand in volume.

Pyrite swelling often appears in the form of cracks in the concrete floor slabs of basements or garages. The cracks are different from normal settlement or shrinkage cracks as they are often star shaped and appear to be lifting the concrete slab, they are also sometimes accompanied by a white residue along the crack lines. Only a pyrite test conducted by a certified lab (Protocol CTQ M-200) can confirm the presence of pyrite and more importantly determine the risks of further damage.

Since 2001, as a measure to stop the proliferation of problems due to Pyrite damage, Quebec quarries have voluntarily implemented a testing of crushed stone for use as backfill under floor slabs. When a builder/contractor orders crushed stone from a quarry and specifies it is for use under concrete slabs the quarry will issue a DB certificate for every truckload that is shipped to the job site indicating the stone has been pre-tested. It is a good practice to obtain whenever possible these certificates so they are kept with the building documents.

Radon - The Silent Killer

Radon is an odourless, colourless, invisible gas that emanates from the soil. It is a naturally occurring soil gas that when released into the atmosphere is diluted without any ill effect on animal or plant life. However, when trapped inside a building the concentration can rise to dangerous levels. After years of research done in the US and Europe, Health Canada announced in 2008 that the safe maximum levels for exposure to radon would be dropped from 800bq/m3 to 200bq/m3.

Testing has revealed the highest concentrations in a home are usually in the basement. Since the trend over the last several decades has been to use the basement as living space (an extra bedroom, a home office, a home cinema room) the risk of exposure to radon has increased.

The risks of radon exposure come from the radioactive components carried with the gas. Because they are totally imperceptible they are unknowingly breathed in where damage can caused at the cellular level to lung tissue. There are no side effects, no irritation, no coughing, no allergic reactions. The symptoms can take years or decades to appear and the first signs are usually the discovery of a cancerous tumour. Health Canada statistics reveal that radon exposure is the second leading cause of lung cancer after tobacco use and accounts for about 10% of lung cancer cases in Canada. In Quebec alone about 400 deaths per year are attributed to radon exposure causing lung cancer.

Monitors are now available that allow for easy and cost effective testing for radon concentrations. It’s probably one of the most important investments you can make for yourself and your loved ones.

Red Ochre / Ferrous Oxyde

Red ochre is a naturally present mineral in the ground throughout the world. It presence is directly related to iron deposits which is one of the most widely used materials in our society. Issues involving red ochre began to appear as the use of underground drainage pipes came into use. The first recorded problems involving red ochre were discovered in farmers fields where drainage pipes has been installed to help drain fields more rapidly from excess water and improve cultivation conditions. Some farmers began to report their drain pipes became clogged with a reddish sludge within only a few years of service.

Research into the problem found that high iron concentrations in the ground combined with water and oxygen allowed for the production of a sludge like material inside the pipes. In some cases, certain bacteria accelerate the production process and also create a form of gelatinous growth. Both of these compounds can quickly block a drain pipe and render it useless.

The french drains installed at the base of a house footing are those that typically will become blocked. Since water is required to support the growth of red ochre the houses most at risk are those where the water table is higher than normal and the pipes submerged in water during longer periods. Given these conditions, once the French drain pipes become clogged the water begins to infiltrate into the basement at the junction point between the footing and the foundation wall.

There is no treatment to eliminate red ochre, in some cases cleaning ports to access the drain pipes can be installed and regular cleaning must be done. In other cases the drain pipes have to be replaced completely and the foundation thoroughly waterproofed.

Symptoms of possible red ochre contamination are rust deposits or orange/black coloured water in the sump pit. When symptoms are present a camera examination of the drain pipes is recommended and water testing can also be done to assess the iron and bacteria concentrations.


Mould is a naturally occurring organism in nature, it serves a very useful purpose as part of the earths’ ecosystem. Only when mould is allowed to grow inside buildings or ventilation systems can it become a health concern as concentrations can reach levels that will cause allergic reactions in some people or even make them sick.

Mould requires two key ingredients to grow: moisture and food. Food can be something as simple as dust on a wall surface while moisture inside buildings comes from two main sources.

In basements, water is a constant threat, being underground, basements are usually moist places and they are often prey to water infiltration from cracks, clogged or missing french drains or simply water diffusion through the concrete walls and floor. Since most basements are now used as living space the walls and floors are closed allowing this moisture to remain trapped and bingo we have perfect conditions for mould to grow, in most cases unknown and unseen behind the walls and under the floors.

On wall/ceiling surfaces mould is often the result of water condensation. Controlling the amount of water vapour in the air (aka RH% of relative humidity) is the most effective way of reducing mould growth on surfaces. Humans create a significant amount of water vapour through breathing and daily activities such as cooking, cleaning, showers, baths, etc. Evacuating excess moisture outside the building can prevent or greatly reduce mould growth. Because water vapour will condense on cool surfaces maintaining good ventilation/air circulation and correcting any areas that are missing insulation will prove effective.

When evidence of mould is discovered we will perform testing to attempt to determine the possible source and cause of the moisture.

Air Quality

Air quality inside a building can be affected by a number of causes some of which are not easily visible. When occupants believe the air quality in a building is suspect, air quality tests can be performed to identify any contaminants that may be present.

Since reliable air quality tests can be fairly expensive it is often suggested to conduct a preliminary forensic assessment of possible causes. Sometimes a trained eye can identify the source of air contamination and recommend corrective actions.

If an air quality test is determined necessary, be careful of companies offering cheap tests since these cannot provide the control, accuracy and completeness of certified labs and are often a waste of money.

Tech can refer you to accredited labs that have certified technicians and laboratories.

Water Damage

Of all the problems faced by buildings, water damage is by far the most frequent and varied. The building envelope and its combination of materials and systems that help protect the occupants from the elements is a complex collection of elements that work together (roof membrane, flashings, water barriers, rain screens, drainage systems, sealants, etc.)

Water back up problems can cause significant damage and clean up costs. Many of these problems are not covered by insurance companies or carry limitation clauses.

Identifying risk areas is the most challenging part of a building inspection. At Tech we use sophisticated tools that allow us to detect moisture trapped inside walls or test damaged areas to ascertain if a leakage problem is still ongoing. We also evaluate drainage system installations and determine if further evaluation is recommended.

Cost of a Building Inspection - How much should I pay for an inspection?

Building inspection today is completely different from the type of building inspection your parents might have ordered a decade or two ago. Today professional building inspectors receive extensive training in building systems and diagnosis of symptoms. Licensed building inspectors with the QABI (Quebec Association of Building Inspectors) must have a diploma obtained from a recognized institution and pass the QABI exams before being accepted as a candidate member. Auditing of inspection reports and field audits are carried out before a candidate member can receive his accreditation. Finally licensed inspectors must carry professional liability insurance and attend a minimum of 40 hours per year of continuous training to maintain their accreditation.

A good inspector will spend at least two to three hours or more, (depending on the size and type of building) performing the on-site investigation and will write a report with complete descriptions of systems, their condition, anomalies or defects observed, recommendations and urgency of repairs. All of this accompanied by photos to illustrate defects.

Many inspectors are not certified, do not carry professional liability insurance and provide check box reports or reports that are templates filled with useless information. Their only way to get clients is to offer low prices and work on volume and hope they never see or hear from their clients again.

At Tech our business has been built on word of mouth referrals. We do little or no advertising as our clients and their satisfaction has earned us their trust, past clients are, in fact, our best salespeople. Our reports are user friendly, easy to understand, informative and interactive when you are connected to the internet.

So although you may pay a little more for a Tech building inspection you are getting your moneys’ worth and more. You don’t buy a house every month so why not make sure you use the best service available.