All About Foundations Guide
New home construction and foundations have evolved due to a focus on energy efficiency, curb appeal, durability, enhanced function and new materials. With all these changes, if a new home is in your future, you get the unique opportunity to express your ultimate dream home vision through how the home is sited on its lot. Along with so many variables is a large cost range. There is no limit on what can be spent, but there are constraints on what can be built. The more a homeowner puts into the land and the foundation, the less may be able to go into the structure. In fact, some families decide to leave certain areas of their new home unfinished, until their finances catch up with their new lifestyle.
I’d like to give you a thumbnail guide on new home foundation construction so you are aware of all that is involved before you dive in. Remember – knowledge is power!
There are several types of foundations to choose from – surface mount, slab, crawlspace and partial or full basement. Besides price, function is an important consideration. If you don’t want or need the extra space below your main floor, there is not much point in having one, unless you believe it’s important for your home’s resale value.
Other considerations are the type of soil on your land, frost line, water tables, drainage, elevations and local building codes. The natural state of your land may also give you an idea of the type of structure that is most suited to its qualities. Some may prefer their new home have a ‘nestled’ look, while others may prefer a bold, ‘in your face’ stance. The best time to think through these issues is before you start choosing plans and colours.
Manufactured homes can be engineered and constructed to be sited on a surface mount pad.
This is possible because of home is constructed on a beam system designed to carry and support the weight of the home, yet allow for some flexibility should the earth under the pad shift slightly over the years.
The Canadian Standards Association has developed a set of specifications for surface mount homes and the manufactured housing industry which is known as the CSA Z240.10.1 code. This standard ensures moisture under the home is managed and the home is on a level, solid site. Once the pad is constructed to this code by a knowledgeable installer, the manufactured home may be blocked on metal stands on concrete or ABS blocks, and wood planks. The home is then affixed to land with tie down straps anchored into the ground. The home is then typically skirted in with a specially designed skirting system.
Surface mounting is the least expensive of the foundation options because less time, labour and materials are required.
Slab foundations are constructed of concrete that is usually 6 to 8 inches thick. The home is then sited on the slab. The construction process includes gravel being spread first to facilitate drainage underneath the concrete and the home. Usually, pipe and utility hookups are installed through the concrete in the slab. Rebar is occasionally used for added support, which may be in the concrete itself to strengthen it. Expansion joists are made along the concrete surface to mitigate any cracking that might occur during the curing process.
Slab foundations are used most often in areas where there is high clay content in the soil or inadequate drainage which can cause settling problems due to inadequate subsurface drainage. If your home is to be built along a shoreline where flooding may occur, this type of foundation may be ideal.
Slab foundations are usually one of the least expensive and the quickest foundations to construct. Often, there is little excavation needed and it is poured along with the footings. A further consideration is ensuring there is access to under the home as it will be necessary to hook up plumbing and any other connections. It will be necessary to ensure the piping under the home is protected from freeze ups. This is normally accomplished by the use of heat tapes and insulation. A source of electricity will be necessary for the heat tape.
Homeowners who prefer this type of foundation usually opt for a garage or a storage building for their extras.
In modular construction, typically there is the requirement of wood beams in the floor for support. The floor is constructed early in the process, and is essential through to transportation and delivery of the home. Additionally, underfloor access is typically required for inter-modular connections (such as plumbing and electrical), therefore, slab foundations are not typically an option when building modularly.
A crawlspace or frost wall foundation is a type of foundation similar to a basement except the home is off of the ground level by about 4 feet. These short walls extend out of the ground from the footings around the perimeter of the foundation to support the home.
Crawlspaces are ideal for lots which are high in moisture content where excessive water can build up. A foundation which supports the home off of the ground will ensure that there is less moisture that can cause damage and rot. Another benefit of this type of foundation is that is allows for easy access to piping and utility areas under the home for initial hookups and any future repairs or installations.
The floor of the crawl space may be crushed stone, or a concrete slab.
Similar to a slab foundation, it is a less expensive type of construction since it involves less time, materials and labour, and it is also necessary to ensure the piping under the home is protected from freeze ups.
A full basement is a common foundation due to its added functionality. The basement is normally the same size as the footprint of the home, but it is also an option to have a full foundation under a portion of the home and a slab under another portion, such as the garage.
The basement can be finished to add to your home’s total living area, or it can be used for storage and finished in time. The intended future use of this space will dictate where plumbing is to be installed in it, as well as windows and doors.
The floor of the basement is usually a slab, and the floor support system. Modern construction options for basement walls are poured concrete and block walls. Again, soil type and lots with high water tables or unsettled soil are factors to consider when choosing which type of foundation suits your lot.
Full basements are more expensive because more labor is required to excavate the site, and more materials are used. A full basement takes more time to construct because of the amount of labour required and the extra time needed to let the concrete set. Normally, a basement takes 2-3 days to pour the concrete and another week for the concrete to harden.
Additionally, basements are now required to be insulated, dry walled, and crack filled – essentially providing a partially finished basement. This requirement adds to the cost of a full basement as well.
If you have any questions about which type of foundation is most suitable for your lifestyle and location, I can help guide you through the nuances. Kent Homes also has engineers on staff who have the engineering expertise to draw a plan for your perfect foundation.
If you are interested in further exploring the manufactured housing option to fill your dream of home ownership, and want to have confidence that you will be living in a home you can comfortably afford, and it fits your life style today, and tomorrow, I welcome your enquiries. We will share our expertise and knowledge with you in a relaxed and professional setting.