Common House Foundations
There are a number of different house foundations in use in residential home construction. They can vary based on a number of reasons, it could be the type and size of the home or the soil conditions and the building techniques used. It may be the cost factor as foundations get more expensive as the more involved they get. It may be climate and location that determines what type of foundation is used and it also may be a building code enforcement that determines which foundation to use.
The foundation is what the entire house sits on and how it is attached to the ground underneath so therefore it is vitally important that it is installed correctly. The foundation affects the stability and structural soundness of the building and must be built with enough strength and integrity to perform without failing. If the foundation fails it could cause the home to have significant damage possible even be torn down.
The most common types of house foundations are slab, crawl spaces and basements. The vast majority of single family homes are built on one of these foundations. Less common types of foundations can be found in areas where flooding may occur such as coastal areas and river floodplains. The homes need to be built high enough to allow the water to not cause damage to the home. This typically requires the homes to built on stilts or pilings which can be made of wood, cinder block or concrete. Once the pilings are installed to the required height the home is then built on top. In areas that can be subject to extreme weather the building codes will require additional measures to ensure the home can withstand these conditions.
A home built on a slab foundation is one where concrete is poured into a form to create the foundation and ground floor of the home. Before the concrete is poured the plumbing and electrical components are installed and the concrete poured around them. Slab homes are commonly found in warmer climates as cold freezing weather can damage concrete as it is directly on the ground. Slab homes have to be built on flat level lots which may require the developer to do additional grading. Slab foundation homes are popular in homes for seniors or retirees because there are usually no or few steps to deal with. The floors are going to be colder when temperatures drop and certain types of flooring cannot be used with a slab. Soil type can be an issue with a slab home which are best suited to stable soil conditions. Tree roots, seismic activity can also cause problems for slab homes. In the unlikely event of a leak or plumbing issues it may be necessary to dig up the concrete to gain access to the problem. So if there is a problem with either it can be an expensive repair.This type of foundation is popular because of the cost savings which allows the builder to sell the homes for less.
Crawl Space Foundation
The next type of house foundation is the crawl space, this is a very common building practice in a lot of the country and works in both cold and warmer climates. A crawl space costs more that a slab because of the extra labor, time and material cost. The foundation for a crawl space starts with a trench dug where the outside walls of the home will be and any structural supports in the center of the home. Concrete is then poured into the trench and when that sets, cinder blocks are built around the exterior typically with a brick front or stucco. A pressure treated board is then attached to this wall and the framing for the home is built on that. In areas of high humidity it is important to have adequate air flow in the crawl space to avoid a buildup of moisture which can quickly develop into mold and wood rotting. Termites are attracted to any wood that is near ground level so care must be taken to prevent termite infestation. A termite treatment for all homes where there is significant termite activity is recommended. Some newer homes are built with a completely sealed crawl space, this reduces the moisture content and improves air quality in the home. At the very least a home with a crawl space should have a well fitting vapor barrier installed. There are plenty of companies that offer services to crawl spaces from minor repairs to complete overhauls. With a crawl space the plumbing and electric components are easy to get to if there is a problem or when moving outlets or cable boxes. A crawl space has the advantage of being warmer than a slab in winter and allows for more flooring options to be used.
A basement is the most expensive house foundation of the three and requires a lot more labor hours and materials. The basement normally houses the main components of the heating and air conditioner, the hot water heater and the plumbing and electrical components.
Basements are common in colder climates where they were built to get the foundations below the frost line to avoid frost heave. Recent advancements in building technology and energy efficiency is requiring them less. Basements can be built in a number of ways, the walls are made when concrete is poured into forms to harden. Sections are made off site, delivered and installed at the site, concrete cinder block walls can also be used. The walls must be waterproofed and care taken to ensure water penetration does not become an issue. It is common for a basement to be used when the ground slopes considerably and it would be better use of the space. A walk out basement has windows and a doorway to the rear or side of the property.
Some basements are very elaborate when finished to provide extra living space in the form of bedrooms or entertainment areas for the family. Some have safe rooms, wine cellars, movie theaters while others never get finished and simply serve as storage and utility rooms. The cost of building a basement really depends on the location and can be a significant addition to the price of a home.
Problems With House Foundations
Each of the house foundations mentioned can over time develop problems that if ignored could become serious. Cracks may form in a slab if there is movement in the underlying soil or if improperly installed. Crawl spaces need to be maintained over time as the combination of weather and exposure to the soil will deteriorate the insulation and possible flooring. Basements are prone to allowing water to get in if not properly waterproofed. As most homes settle over time it is possible for this to affect the foundations as well.
Here is a few related articles you might find interesting from real estate professionals…
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