Advice | Cognitio Consultants | Building Consulting Services in Montreal

Building advice

The purpose of this section is to explain some basic building maintenance principles.

construction worker working on a building roof

Roofing

The criteria to be taken into account when choosing a roof are as follow

Duration: how long will the roof last?
Resistance: is the roof capable of holding up during natural disasters such as forest fires or strong winds?
Weight: is the roof too heavy for the framework?
Tilt: what type of tilt (slope) does the roof have?
Aesthetics: which style do you look for and will it be adapted to the house?
Materials: is the materials ecological and recyclable?
Standards: is the type of roofing you want in accordance with local standards?
The price: and finally, how much does it cost?

When it comes to covering or re-roofing, the variety and products on the market are numerous. Although asphalt shingles are the most widespread, sheet metal and plastic tiles take a large share of the market.

Types of roofing

Model	Features and composition	Benefits, drawbacks, guarantee/warranty
Asphalt Shingles	Two compositions: organic covered in crushed stone, or fiberglass.	Benefits: economical and popular; require minimum maintenance; easy to install. Drawbacks: some models are less resistant to heavy rains and strong winds. Guaranteed for 20 to 40 years according to the model.
Cedar shingles	There are two kinds of wood shingle available: cedar and pressure-treated wood, cedar being the more widespread. Different finishes: natural, pre-stained, and pre-aged. The weathered look of pre-aged shingles adds old-world charm to a home, something many homeowners are looking for.	Benefits: attractive and natural; rot-proof; naturally insect-resistant; more common in warmer climate zones; extra-A Grade used for roofing; you can use an oil to whiten or age the cedar; can be factory-stained. Drawbacks: high installation costs; require periodic maintenance; flammable material. Guaranteed 30 years.
Fiberglass shingles	Constructed with a combination of clay, resin and fiberglass. Imitates cedar roofing shingles without the risks associated with fire.	Benefits: damp-resistant; zero maintenance; good durability (more than 50 years). Drawbacks: relatively expensive.
Metal Tiles	Made chiefly of steel sheeting, (galvanized or stainless), copper sheeting and tiles. The cost of a steel roof varies according to the sheet profile, paint used, and shape of the roof.	Benefits: very good durability (more than 100 years); does not rust; available in steel, galvanized steel, titanium, galvalume, copper, aluminum. Drawbacks: must be installed by roofing specialists. Guaranteed 50 years.
Copper	Associated with luxury roofs and expensive homes.	Benefits: oxidation produces a characteristic pale green patina over time; excellent durability. Drawbacks: installation should be entrusted to professionals. Lifetime Warranty
Galvanized Steel	Galvanization protects the metal against corrosion. There are various processes: galvalume (registered trademark) is covered with zinc to improve its weathering capabilities, and galvanized steel is made by passing it through a bath of molten zinc.	Benefits: good durability (approx. 50 years); corrosion-resistant; does not crack, split or break; lightweight; zero maintenance. 40 Year Limited Warranty
Stainless Steel		Benefits: attractive; doesn’t rust; extremely durable (50 years or more); lightweight; does not crack, split or break. Lifetime Warranty
Plastic Tiles	Imitates the appearance of slate, but it’s a lot less expensive and less fragile during installation. Installation is fairly simple, and an underlayment is not required.	Benefits: extremely resistant to wind; does not ripple; resistant to temperature extremes; water, damp and mould-resistant; lightweight and easy to install. Drawbacks: original colour may fade over time. Limited Life Warranty
Slate	Natural stone (shale clay) extracted directly from the earth. Split into perfectly flat thin layers.	Benefits: extremely durable (more than 100 years); rare as a roof covering in our climate; does not fade with exposure to the sun; heavy product and therefore resistant to strong winds. Drawbacks: caution is required during installation due to the fragility of the product; must be installed by roofing professionals. Lifetime Warranty
Clay Roof Tiles	Product more widely used in Mediterranean climates.	Benefits: extremely durable. Drawbacks: more rare in our climate, since it adapts poorly to cold conditions and changes in temperature; roof structure of an existing house may need reinforcing due to increased weight.
Concrete Tiles	Concrete tiles have many interesting features; Most tiles are installed using a specifically designed system of fasteners; The fastener is attached to the roof and not the tile directly.	Benefits: attractive; very resistant to changes in temperature, rain, hail, fire; although appropriate for northern climates, it’s not common; extremely durable (100 years). Drawbacks: roof structure of an existing house may need reinforcing due to increased weight. Guaranteed approximately 50 years.

SOURCE: Rona

Foundations

Foundations are essential elements of a construction. They ensure the stability of the building but also the durability of the superstructure.

There are mainly two types of foundation:

Superficial foundations
Deep foundations

Superficial foundations

Semelle de fondation d'un bâtiment The superficial foundation is commonly composed of a concrete foundation wall supported on a base, the footing, which reduces the pressure on the ground. This common construction technique allows the weight of the building to be redistributed and balanced according to the force exerted by the building on the bearing capacity of the ground. This is the most economical method of making seats. This method is generally suitable for soils of reasonable lift, not necessarily rocky, and commercial or institutional buildings with a steel or concrete structure a few floors. In the case of buildings of several floors, which are heavier, one must seek to rely on a soil of better lift. If the rock is reached, it will limit the size of the footing.

In Quebec, clay soils are found in the most inhabited parts of the territory, notably in the St. Lawrence Valley, the Ottawa Valley and the Saguenay-Lac-Saint-Jean region. The construction of a house on clay soil is a common practice. However, since clay soils may be highly compressible, it is important to take the necessary precautions to limit the risk of subsidence of foundations. If you must build in a place where the soil is clayey, take all precautions to reduce the risk of subsidence of the foundations.

Consider the soil characteristics to properly design the foundation footings.

Download the maps of the sediment deposits of Montreal island.

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Deep foundations

Foreuse pour pieux de fondation Where superficial foundations are not feasible due to the presence of compressible soils, deep foundations allow the structural loads to be transferred to the deepest layers. In the case of a deep foundation, piles of different types will be driven into the soil so that their base or tip reaches densely-coated substrate layers or even a rocky basement.

Thus, contrary to a continuous or conventional sole, these piles are placed in a point-like manner at determined points to form a network of points of support. Originally made of wood, the piles are henceforth commonly constructed of reinforced concrete or metal.

Did you know?

Venice is a city built on piles. This city suggests that it was built on the water and yet one of the reasons for these high piles comes from the nature of its soil. For large buildings, shallow soil can not withstand such loads and it has been necessary to build piles.