Understanding House Foundations

A basement foundation requires digging deeper into the ground so that there’s enough space for an underground living area. This can be about an 8 ft deep hole where the floor level matches that of the main house.

A basement foundation needs structural foundation walls on concrete footings around the outside of the basement. The concrete footings have to be at least 12 inches below ground level and frost line. Once the concrete footing is in place, you can pour beams and erect foundation walls.

This type of foundation is secure and provides additional square footage to the home. Because they’re deeper and more solid, they are more resistant to fire and natural disasters. The extra living space can also be heated and cooled like the rest of the house.

Where there are uneven surfaces, a crawlspace stem wall is used for house foundations. In this case, the house is built on a slight elevation that leaves a crawl-space that you can use for storage, a furnace or other equipment.

Because it's on an elevation, your home is protected from flooding and other seepage damage. It also allows you easy access to plumbing, electrical and mechanical systems. This is a cheaper option than a basement foundation because it doesn’t require you to dig into the ground.

A slab foundation is a slab of concrete that’s poured at a single time. They are less expensive and faster to construct. Unlike basement foundations, concrete slab foundations are only 2 feet deep with wire mesh and steel reinforcing bars.

One of the benefits of the concrete slab foundation is that there is no crawl-space, so you don’t need to worry about maintenance or moisture issues. They don’t crumble over time from simple wear and tear. A concrete slab foundation is not ideal for the cold because the concrete cracks when the ground freezes and thaws.

A big issue with concrete slab foundations is that the sewer and plumbing pipes are below the concrete slab. This means that if you have any issues with sewage or drainage, you’ll have to cut into your homes foundation. This can increase the cost of any plumbing repairs.

You’ll find wood foundations in older homes from the 1960s. The wood is treated so it's resistant to decay and can last you a long time. Without the equipment and labour needed to pour concrete, wood foundations can be easier and cheaper to install.

The type of wood used for this foundation can make a difference in the price. Cypress, redwood and cedar are more resistant to insects and mould but can be more expensive. Wood foundations can only be used in dry soil, so there are additional limitations to using wood foundations in Canadian weather.

Pier and beam foundations are ideal for areas where the ground is constantly shifting. This can include coastal areas or areas near water that are prone to flooding or eroding. They require more planning to ensure that it's protected from moisture.

Pillars are placed into the deepest layers of the ground. These pillars can be 15 yards long to ensure that it offers the right support and will not be impacted by shifting soil conditions. It's more expensive because it requires additional equipment and added planning.

There are some warning signs that you can look out for. The first thing you need to consider is cracks in the foundation. Vertical or diagonal cracks can arise because the foundation was not set evenly. Any cracks should be repaired to prevent water damage.

You should also look out for bowed foundation walls or horizontal cracks. These are usually because of pressure from the soil outside the wall. Excessive moisture makes the soil expand and push against your house foundation. When the soil dries, it contracts.

You can have cracks in the slab because it wasn’t poured correctly, concrete shrinking as it cools or soil expansion. Any cracks can lead to water damage.

Cracks on the home exterior and interior are also a sign of foundation issues. It can be caused by rot that compromises your house's foundation. The cracked drywall at the top of windows and doors which makes them hard to open and close is another warning sign.

Basement foundations are dug deeper so they have a longer life expectancy of more than 100 years. You may still need to do some extra waterproofing every 10 years or so. Prices in 2022 are rising and now it is on average $33 per square foot.

Crawlspace stem walls last longer with a vapour barrier. The life expectancy can vary depending on the weather and moisture conditions.

Concrete slab foundations are also made of concrete, so they have a long life expectancy of more than 100 years. If the house is located in wet conditions, it may be susceptible to water damage and cracks.

Wood foundations are not as long-lasting even with treatments. Treated wood can last 40 to 75 years, with an average of 60 years.

The life expectancy of pier and beam foundations is about 70 to 100, with an average of 80 years. The climate and weather conditions can impact life expectancy at a higher rate.  

Check for cracks and water damage regularly. But don’t wait too long. If you’re seeing cracks, there’s already damage. Have a licensed contractor come in and do regular checks so you can catch the damage before it gets worse.

Check for cracks on the window frames and drywall. This can indicate damage from soil pressure or moisture. 

While crawlspace stem walls are more resistant to termites, you may need to look more carefully and keep an eye out for mould and mildew. You can end up with more moisture in the crawlspace that can lead to moisture and structural damage in the future.

To maintain this type of house foundation, you will need to conduct routine checks of the crawlspace to make sure there are no cracks. You also want to continuously check for leaks from plumbing equipment. Any moisture and leaks can weaken the entire infrastructure.

Installing vapour barriers can provide some protection. These may need to be checked and upgraded as needed.

Like basement foundations, you want to keep an eye out for cracks. If you’ve had an especially rainy season, you may want to be extra careful and do more thorough checks.

Wood foundations don’t last as long as concrete foundations, so you may have to do ongoing checks especially if the home is 40 years or older.

Pier and beam foundations are more expensive and need more maintenance as the soil is constantly shifting. Depending on the weather situation, you may want to get a licensed contractor to do regular checks where you see cracks or damage or not. Being proactive can make a huge difference for the life of your house foundation.

Basement foundations are the most expensive type of basement. You can end up paying $20 per square foot for a basement foundation. Prices in 2022 are rising and now it is on average $33 per square foot.

Crawlspace stem walls are above ground, so they can cost about $8 per square foot to replace.

Concrete slab foundations can cost about $5 per square foot to replace. These are cheaper to install before there is no digging required. This is also the cost you would need to consider if there are any sewage or drainage issues to repair. 

Wood foundations are generally cheaper than concrete foundations because it doesn't require extensive labour and equipment. You also don't need to dig as deep. The cost of wood foundations depends on the type of wood you choose and the treatments you add. 

Pier and beam foundations require a lot more planning before they can be implemented. This is why the cost of the foundations varies depending on how much work is required. You will usually get a customized quote for your particular needs.