TYPES OF HOME
The average house weighs over 200 tons, meaning that the choice of foundation is critically important. A foundation does two key roles: firstly, it supports the structure of the home above it, providing stability but also some flexibility; secondly, it provides stability from the ground below – this is particularly important if you have surrounding ground that is prone to flooding or freezing.
Making the right selection is probably the most important decision you’ll make when it comes to building a home. The range of options is large, and a lot will depend on the size and location of the home, although your budget may also play a role. For a better sense of the costs of different foundation types, see our guide The Average Cost of Home Foundation.
This guide will walk you through all of the different options for a home foundation, from the simplest to the most advanced.
The first step when building a foundation is to work out which option is best for you. This will be contingent upon a number of factors.
Where your home is located is the first important issue to take into account. The geographical and environmental location of your home will shape the requirements of your foundation, and therefore will make a difference when it comes to structure and materials. Even more specifically, you need to look at the ground that is under the foundation. The two key issues to examine here are soil type and the water table.
If you live in a warm climate, wood may not be a good foundation material because of the likelihood of termites. By contrast, a climate where there are regular periods of freezing temperatures may lead to concrete foundation cracking. A mild climate gives the most options when it comes to foundations.
Purpose of Foundation
The size of your proposed home is also a factor in determining what type is best for you. For example, if you are planning a large house, you will need a large, solid foundation. If you’re planning a smaller structure, such as for a shed, you will have a greater range of options. You should also consider whether you need access to utilities.
The foundation of your home can be as unique as your house itself – covering a range of different shapes, materials, and construction methods. However, you can generally group foundation structures into four distinct types.
Concrete slab foundations, sometimes referred to as slab-on-grade foundations, are the cheapest and easiest foundation types to install. In order to lay a concrete slab foundation, you create an outline of a home and pour concrete that is roughly four to eight inches thick directly onto the ground.
The perimeter of the foundation is thicker, around 2 feet, for extra reinforcement. Into the foundation, you embed steel rods for strength and drainage pipes to prevent water damage, and then you wait for it to dry.
Concrete slabs have the benefit of being cheap, simple, and provide no space between home and foundation for mold or termites to get in. However, this lack of space can lead to warming, making it difficult in warmer climates.
The two main types of concrete slab foundations are monolithic and stem wall.
Frost-protected foundations are extremely clever pieces of engineering. They use geothermal principles to not only prevent too much heat loss from the home but also prevent the ground around the house from freezing.
A frost-protected foundation uses foam insulation on the exterior of the foundation. The heat that is lost from the building is therefore sent to the ground around the home, rather than into the air.
This helps to protect the foundation. Frost-protection systems can be combined with concrete slab foundations to help keep them structurally sound even in freezing temperatures.
Basement foundations are dug deeper than a concrete slab foundation – usually eight feet deep. They are surrounded by a fence of pillars, which form the wall of the basement; this also provides added strength to the structure of the home.
There are two main types of basement foundations:
The difference between the two is that a daylight basement has windows above ground level, and may even have a door that leads outside. This makes them more suitable for homes that are on uneven ground (because the basement may be below ground on one side of the house, and above it on the other).
The benefit of a basement is that you add square footage to the size of your home without increasing the house’s physical footprint. However, as a result of this, basement foundations are more expensive and can result in additional maintenance.
Crawl Space Foundation:
A crawl space foundation consists of a series of pillars three or four feet high that help to elevate the structure of the house. These are used in situations where the soil is particularly tough to dig through, or the house needs to be raised off the ground – perhaps because it is located in an area of flooding.
Pier and Beam Foundation:
Pier and beam foundations were more common in the United States prior to the 1960s. The construction involves small pads of concrete that are connected to the home via a series of rods. Although usually used in circumstances where it’s difficult to lay a traditional foundation – such as on the very uneven ground – they are durable and long-lasting.
Pier and grade beam foundations can be expensive to lay and often tend to be used for smaller structures such as sheds. They can also cause ventilation problems. Generally speaking, a contractor will find other solutions where possible rather than use pier and grade beam foundations.
Mobile Home Foundation:
If you intend to permanently locate a mobile home in a single location, then you can build a foundation. There are four types of foundations you can use for a mobile home:
In effect, therefore, a mobile home is no different from a regular home when it comes to foundations, and the same factors will apply to determine which is best for you.
Even once you’ve chosen the structure of your foundation, there is a multitude of options when it comes to what materials you use. Again, your contractor will be able to make recommendations based upon the specific requirements of your home and the climate you are building in.
HERE ARE THE FOUNDATION MATERIAL OPTIONS:
As with a concrete slab foundation, poured concrete is the simplest possible foundation material. Many contractors like working with poured concrete because it is easy to use. However, it also provides structural benefits – because your foundation is one single piece of concrete, they don’t often crack or allow water to enter. This also makes them extremely robust and enduring.
Poured Concrete Panel
A poured concrete panel foundation is made up of several pieces of prefabricated panels that slot together to make a solid foundation. The downside of using this system is that there are small gaps between panels that mold and water can get in. You also need to move the panels into position with a crane.
A concrete masonry unit is built with a series of large concrete bricks, sealed with mortar. This helps to create a very solid structure while also making it possible to customize the shape and outline of your home. You may need to do additional foundation waterproofing since this type of foundation can be very porous. It is also very labor-intensive.
Many historic buildings have a foundation made exclusively of stone; however, it is not at all common in modern homes for a stone foundation. If you do want the rustic look, you will need to find a niche professional to install the stones. Many contractors can achieve the same effect by adding a stone facade to an existing foundation.
Wood foundations became more and more common after the 1960s when pressure-treated lumber became widely available. Wood is relatively environmentally-friendly, cheap, and easy to put together to create a solid structure. However, unlike concrete, wood does decay over time, meaning it isn’t the best foundation to use in the long term.
Knowing about the different types of the foundation is vitally important when it comes to building a house. However, it’s one of the less exciting parts of creating a home, and so many homeowners don’t do their research.
As shown above, however, this can end up costing money or resulting in a different type of home than expected.
Deciding whether you want a crawl space or a full basement, whether you’re using poured concrete, or stone all impacts the cost, the structure, and the footprint of your home, so it’s imperative that you do your research.