House foundation types

Understanding your house’s foundation type is important when it comes to home insurance. Your premium will be determined, in part, by the type of foundation that supports your home. Depending on where you live in the country and the climate, type of soil and groundwater levels in the area, your home will most likely have one of three types of foundation:

  • A slab foundation uses concrete to support the weight of the home and is usually concrete poured onto the ground. It is a very cost efficient type of foundation, involving very little site preparation, minimal formwork for the concrete, and minimal labour to construct. From a structural perspective, concrete slab foundations provide a durable, level surface for floors; homes built on slabs rarely experience problems with creaking floors or doors that won’t open and close as a house settles over time.

  • A basement is built in a hole dug 6 to 8 feet into the ground; the depth of excavation usually depends upon soil conditions, because some types of soil require a deeper foundation in order to provide proper stability. Full basements provide space for the household utilities along with the head space that allows for building full rooms below grade. Basement rooms are often the least expensive floor space you can finish in a home since the perimeter walls are already built.

    Modern basements are usually constructed of poured concrete, in order to enjoy the same durability advantages as concrete slab foundations. In some parts of Canada, the basements of older homes may be constructed using concrete blocks or bricks; while these older methods of construction are reasonably solid, they do present an increased risk of water intrusion and can be more difficult to diagnose when a loss occurs.

  • A crawl space is a raised foundation which, as its name suggests, is built just high enough to allow a person room to crawl underneath. It provides an accessible yet enclosed space to run heating ducts, plumbing and wiring, while elevating the home to mitigate moisture and pest intrusion.

    Crawl spaces are also usually constructed on top of a concrete slab, but older homes may use a brick foundation. Some very old homes are built on top of a packed-dirt crawlspace, with no continuous foundation whatsoever.

The type of foundation your home contains will determine whether or not an insurance provider will insure your home, so you should be prepared to answer some questions about the foundation of your home when you get a quote. For example, Square One Insurance will only insure houses built on a continuous foundation, so we will ask you what form of foundation supports your house. We will also ask if the foundation shows any visible signs of erosion or cracking, because these signs of damage may suggest that your house requires repair in order to reduce the danger of structural failure.

Some homes are not built on a foundation at all, such as mobile homes, modular homes and very old structures. These types of structure sometimes present a unique risk that will need to be referred to a specialty insurance provider, who will offer products specifically tailored for their needs.

Once we have determined that your home is built on a continuous foundation, Square One will calculate a rebuilding cost for the home. The foundation is a significant factor in this calculation and will be a factor in your home’s overall rebuilding cost. Some individuals question the need to insure the foundation, because it is a largely permanent feature of most homes; however, severe losses can result in permanent damage even to poured concrete foundations, which may need to be excavated and replaced in order to rebuild a safe and structurally-sound house.

There are some policy exclusions to be aware of when insuring your home and you need to be aware of them in the event of a loss. For example, Square One does not cover loss or damage caused by as wear and tear, inherent defect, corrosion, mold, condensation or contamination, to name a few. These losses frequently occur when elements of a home’s foundation begin to fail, permitting the ingress of water over time, or when a foundation is overwhelmed by external forces like freeze/thaw cycles, a rising water table, or tree roots.

Other exclusions to be aware of include loss or damage caused by settling, sinking, buckling or cracking of the structure. These highlight the importance of carefully constructing a robust foundation, on properly graded and packed land, to ensure that the foundation doesn’t crack as a result of the ground changing shape over time. Loss or damage caused by freezing, thawing, pressure or weight of water or ice to the foundation is also excluded; these highlight the importance of surrounding a home’s foundation with adequate drainage systems and sump pumps.

In short, it’s important to ensure that the foundation of your home, whether it is slab, crawl space or basement, is in good condition. If it is not, you may find yourself in a situation where you may not be covered for any damage under your home insurance policy. While this is easy to achieve when building your own home from the ground up, it may be more of a challenge when purchasing an existing home. In those circumstances, your best bet is to conduct thorough structural inspections prior to purchase; these inspections can help to identify any potential deficiencies in a home’s foundation, and to help you plan for the preventive maintenance that will become necessary as the foundation continues to age over time. For more information on building foundations, or to get a quote on your home insurance, contact Square One at 1.855.331.6933.


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