Tuesday, January 28, 2014

Infrared Thermal Imaging

What is it?

Infrared is electromagnetic radiation emitted by objects. Most objects unless at absolute zero, emit some form of infrared radiation. It has longer wavelength than visible light, thus it cannot be seen by a naked eye. Infrared Thermography is referred to detecting this heat signatures of various objects through a infrared thermal camera. The camera detects the infrared light emitted from various objects and shows it as different colors (depending on the palette you choose). Colder objects are shown darker and the hot objects shown lighter.

There is a great deal of confusion in the minds of people about what a thermal image camera can or cannot do. I would like to highlight few points here!

1. Infrared red camera does not have an x-ray vision. It cannot see through walls or objects. There have been instances when an Home Inspector was analyzing the house during Home Inspection and the people are scared and don't want to be in the field of view fearing it can see through the clothing. Well, it does not have any such ability. Again it does not have an x-ray vision.

2. The infrared camera does not emit any radiation. It just a devise to detect the infrared heat signatures emitted or reflected by any object.

3. It is not a magical devise and require favourable conditions and great deal of skill and experience to interpret the findings. Furthermore, the findings required to be substantiated by moisture meter. There has been instances where due to lack of experience and knowledge people have given wrong diagnosis. Believe me its very easy to get excited and to be fooled by this devise. Always consult a professional trained and experienced in both building construction and thermal imaging for proper diagnosis.

4. It is not a digital camera (few models have digital camera built in as additional feature). It only detects the heat signatures emitted or reflected by the objects. Therefore, it needs DELTA T which is the difference in temperature between the objects or inside and outside of the building to display and work properly. When the difference in temperature between inside and outside is very low or almost equal it will not work properly.

Working with and operating thermal camera and interpreting its images require great deal of skill and experience. Its very easy to go wrong or arrive at the false diagnosis. 


Sunday, January 19, 2014

What is AFCI (Arc Fault Circuit Interrupter)

What it is

AFCI (ARC Fault Circuit Interrupter) are the special circuit breakers inside the main Electrical panel which detects arching at the outlets in addition to performing as regular circuit breakers which offer protection against overload and short circuiting. They are very sophisticated devises which can detect special waveforms which are generated during arching at the outlet. AFCI can distinguish between the arching caused by regular operation i.e pulling out a cord and the one caused by an arc fault.

When the arc fault is detected the breakers opens the internal circuits within and thus stops the flow of current. Licensed Electrical contractor must be contacted to determine the cause of tripping before resetting it again.

What it an Arc Fault

We know that AFCI detects arc fault. But what exactly is an Arc Fault? To understand that first we need to know what is an arc? Arc is a luminous discharge of current that is formed when strong current jumps a gap (air) in a circuit or between two electrodes. The arc when generated produces heat and light which can burn the combustible material it comes in contact with. In houses arc fault is caused when loose or corroded connections make intermittent contact and causes arc. Arching should not be confused with short circuiting which is caused when a hot wire comes in contact with neutral or ground wire. If you ever heard buzzing or hissing sound at the outlets that is caused by arching.

Which circuits are protected with AFCI

After 2002 all 15 amp and 20 amp outlets in the bedrooms needs to be protected by AFCI breakers. In future more areas will be required to be protected. Every year many houses get burnt by fires caused by arc faults in the houses causing great deal of loss of life and property.

Sunday, January 12, 2014

Types of Wood Flooring

There are basically 3 types of wooden flooring used in the houses.

1. Hardwood Flooring

The hardwood as the name suggest are the planks cut from actual timber to specified dimension. They are either packed unfinished to be finished  / stained at the site or factory finished. They come in variety of finishes and styles. Depending upon the requirement they can be flat sawn, quarter sawn or rift sawn to produce particular finish. Wooden flooring planks are usually 3/4"  thick and are nailed to the subfloor during installation. They have thicker wear surface and can be sanded multiple times. The hardwood floors are difficult to install where concrete is used as a subfloor for example basements and apartments.

2. Engineered wood Flooring

The engineered wood composed of top layer of wood veneer called lamella over core which can be of plywood, finger core construction or fibreboard. Engineered wood flooring is most popular wood flooring in the world. Only in North America Hardwood flooring is used more. However, it is increasing in popularity. Each layer of Engineered wood is run 90° to increase the stability and strength. This increased stability enables it to be used anywhere on any subfloor including concrete. Furthermore, it is less prone to expansion, curling and coupling than that of hard wood flooring. It is often confused with laminate and vinyl floors . Laminate uses an image of wood on its surface and vinyl flooring is plastic formed to look like a wood. Engineered wood can be from 3ply to 7ply, durability and cost increases with increasing number of plies.

The advantages of Engineered wood flooring over Hardwood flooring.

1. Can be installed on any subfloor including concrete.

2. It is not limited in plank size.

3. Is less prone to gapping, curling and cupping.

4. Unlike solid wood flooring it can be used where radiant floor heating is installed.

5. With Engineered wood mostly factory finished. The finish is more durable and drying time of the finish is saved.

6. Less labour intensive to install thus cost and time of installation is less.

3. Laminate Flooring

Perhaps the cheapest and least durable of all the three types of flooring mentioned here. Laminate flooring is basically not a wood flooring. It is a multi-layer synthetic flooring product fused together with a lamination process. Lamination flooring simulates wood or stone with photographic applique layer under clear protective layer. The inner core is composed of melamine resin and fibre board materials.

Laminate flooring has grown in popularity as it is very easy to install and is relatively inexpensive. It can be used in apartments with concrete as a subfloor with tongue and groove assembly.

Monday, January 6, 2014

What causes concrete to crack

What is concrete?

Concrete is a mixture of cement, sand and aggregate mixed in certain proportions determined by the strength required. When water is added to the mixture a chemical reaction occurs by which concrete becomes solid. Water cement ratio (amount of water per bags of cement) is very important. If more water is added concrete losses its compressive strength. However, add to little and the concrete is not workable. Additional compounds usually known as admixtures are also added to concrete mixture to improve the workability of the concrete.  Concrete is strong in compression but weaker in tension. Therefore, to improve its tensile strength steel reinforcement is added.

What causes cracks?

Cracks in concrete are inevitable. Although good workmanship and quality control can avoid disasters. However, they cannot prevent cracks from developing over period of time. Cracks in the concrete are a result of many different reasons. Few of them can be!


Concrete in its plastic state contains water, when water evaporates during curing of concrete, it shrinks and stresses develop. To release these stresses cracks develop in concrete. These cracks can develop anywhere on concrete which can be unsightly. Therefore, a good practise is to construct control joints (not expansion joints) at regular intervals to control where the cracks should develop so that they don't appear ugly.


Concrete like any other material expands and contracts as per variations in temperature. When concrete expands and pushes against the adjoining material, stresses develop resulting in development of cracks. Expansion joints are required at regular distances and various other locations to prevent these cracks.


Ground conditions also result in development of cracks in the concrete. Certain types of soils expands when wet and contracts when dry. Furthermore, frost will make the soil to expand and while thawing the soil contracts. This cycle of expansion and contraction causes concrete to crack.


All buildings settle little bit after getting constructed. If the ground underneath was not compacted properly, differential or irregular settlement can occur resulting in development of cracks.


Concrete is designed to take certain amount of load. If it is loaded beyond that limit cracks might appear. Furthermore, the ground below the concrete may not be compacted properly or is wet, making it to settle under load and as a result cracking the concrete.


If the concrete dries to quickly then the crazing cracks appear on the surface.

Thursday, January 2, 2014

Condensation on windows

What is it?

Condensation refers to the accumulation of moisture on the window panes. It is an indication of high levels of relative humidity inside the house. Warm air can hold much higher water vapour content than colder air. When the warm air comes in contact with the glass panes which are colder (in winters), the air temperature reduces and so does it ability to hold water vapours. When the temperature of air reaches dew point, the excess water vapours changes to liquid and drips down the windows as condensation.

How to prevent condensation?

In order to prevent condensation the relative humidity or the moisture content of the inside air has to be reduced as well as circulation of air near the windows needs to be improved.

Condensation can be prevented by:

1. Increasing the air circulation near the windows. That can be achieved by opening the louvers and curtains and also if the weather permits opening up the windows. In winters fan can be used to improve the air circulation around the window as well.

2. By using dehumidifier to reduce the humidity of the air.

3. Running kitchen and bathroom exhaust fans till fifteen to twenty minutes after taking the bath or cooking.

4. Checking the exhaust pipe for any leaks for your clothes dryer.  Clothes dryer exhaust contains high degree of moisture in it and if not properly sealed can add a great deal of moisture to the inside air.

5. Checking and changing your furnace filters regularly.

6. Caulking around the windows to prevent air leakages.

7. Cleaning vents and ducts every 1 to 2 years.

8. Repairing any cracks in foundation walls, floors.

9. Installing double glazed or insulated glass windows instead of single pane glass windows if any present in your house.

Excessive condensation can cause permanent damage to the windows and can promote mold and fungi growth in the house. Therefore, it should be controlled and mitigated for heath of your family.

Find us on google places / maps Home Inspection Mississauga, Home Inspector Mississauga, Mississauga Home Inspection