Buying older houses in Toronto: Which hidden problems to expect?

I would like to talk about potential problems that potential buyers of old houses in Toronto may encounter. For the last 20+ years being with clients who bought, renovated and re sold older Toronto’s houses  I became professional in identifying any hidden issues especially with houses build shortly after WW2 .

What do we call old houses? A portion of the districts South of 401 along Yonge Street were built in the 1920s. It is widely believed that the homes of the 1920s and 1930s were high quality and could stand for another century. This is true, but this applies only to the houses built in the 1920s and 1930s, standing on very wide lots. Those normally have natural stone foundations and some metal beams making them able to stay a century and more.

I would say in this article more about houses build in early 1950s shortly after WW2 when it was mass construction on narrow lots and some were initially build with septic tank and septic bed shortly replaced by sewerage in end of 1950s.

What hidden problems can be encountered in the old houses of Toronto?
I will try to tell future home owners about the general problems that are not visible to the eye, which concern electricity, insulation and heating, water supply, as well as hidden problems with the foundation and problems with the site.

A damp basement or a bad roof, windows or a wrong drainage of rainwater is something that can be seen right away, and I do not touch on such problems in this article. What I am talking about are the problems that are not initially obvious.


1. In any house that is getting electricity from the street via wires in the air (new subdivisions have underground wiring) , these have a certain cross-section which determines the size of the current. Today, the standard is 100-200 Amperes, but earlier there was less than 60 A in the pipeline, which is not enough for a modern house. With today’s energy efficiency appliances 100 A is OK but if you plan to have an electric car you will need 200A service line.

2. Aluminum wires! Yes, Toronto tentatively from 1965 to 1975 used aluminum in the wiring, and residents may expect problems with contacts and connections.

3. Wiring on reels and tubes. In houses built before the 40’s they used ceramic coils and pipes for the insulation of copper wire. Today, insurance companies require from new home owner to replace it which may be an unexpected cost of homeownership.

4. Lack of grounding in the sockets. Most electrical appliances require grounding. That is, you have to make sure to lead a wire to each of these outlets, and then fill up excess holes. Often, badly embedded strips are visible in old houses on the walls and ceiling.

5. Old incoming wires for cable and phone that can not provide good Internet speed and require replacement.

Insulation and heating

1. Absence of insulation in the outer walls of brick houses. The R value of standard brick wall is considered R-8 compare to latest houses build with R-22 walls. You will have to add insulation from inside house for all exterior walls or do new stucco outside with extra R 10 insulation. In practice most of brick house are not 100% brick they used block inside which considered to have holes and better R value. Houses here were built in such a way that only every fifth row of bricks was turned across, and not more often, as usually catches the eye in the brickwork pattern in Europe ( every second or third brick was rotated) . The reason for the 5th row is that since the 50’s, narrow block was used instead of two bricks inside the building, and even for these blocks a different mortar was used compare to mortar used for outer walls.

2. Poor insulation in the attic and no vapor barrier. Today, after putting insulation into a house, just before the finish coat, they have a vapor barrier layer (foil or polyethylene). That is, the whole house is in a “plastic bag”, which creates certain problems with the humidity and work of wood fireplaces, and also disrupts the operation of any air-circulation systems, such as fans and hot-water heater hoods. Theoretically, 3 layers of oil paint serve as a vapor barrier in the old houses, but starting from 2016 oil paint is prohibited for sale and it getting hard to find it.

3. Use of asbestos in the insulation of heating pipes and hot water pipes.

4. Heating systems with low efficiency that are expensive to operate. These include both electric and diesel heating, which is still found in some Toronto homes.

5. Presence of old tanks for diesel fuel in the basement of a house or buried somewhere nearby. Old septic tank and septic bed may be present on the property.

Water supply

1. Size and material of the incoming water supply pipe!
The size determines how the water runs through your house if several sources of water intake are turned on at once. Today’s standards are 3​/4 or 1 inch.
A lead incoming pipe with cold water is a known problem! It is necessary to make a test and run to the municipality with a request to queue up the replacement of the incoming line, if it is lead.

2. There are houses where not all pipes are copper, and part of the system is represented by ordinary steel pipes that rot from inside and on threaded joints. By the way, in old houses two sizes of copper pipes were used,  mostly thinner M and rarely in commercial or more expensive properties type L, and, accordingly, where some money could be saved, builder used M type copper pipe. Type L has thicker walls and a higher pressure and frost resistance rating.

3. Flooding in the drain system. Underground ceramic and vertical cast iron drain pipes can be mechanically damaged. If you have this problem caused by the roots of tree located at the City property, then you have the opportunity to get a grant to replace the pipes from City of Toronto. That applies only to damage caused by tree roots located on City property.

4. You may experience issues with the city drain pipes. Check local building department about storm pipes on your street. Some older streets do not have separate storm system for draining water (the storm drainage system designed for rainwater and meltwater simply goes to the sewer) Over time, debris from the roof clogs the general drain, and the flow of water slows down and is disturbed.

Hidden problems with the foundation

In some houses in Toronto, the second and third floors were completed after the house stood for many years. Such homes will be recognized by an experienced agent at once – and tell you where the walls are cracked or the floor has warped. Such “extensions” can be defined from the outside, and inside – as a rule, different floors have different finishes and the thickness of the outer walls.

Problems with the lot site

There are a number of other problems connected with the fact that part of the building or property parking lot is located in another lot or under the territory of the city. For example, the steps or part of the support wall may actually not be under your ownership. You will have to sign a contract with the city or eliminate defects. This problem will be partially helped financially by insurance when buying a house, but in addition you will have to spend money on future  insurance since it is required by the city authorities for registration.