Foundation Types for House Plans

May 24, 2017

Foundation Types for House Plans

The foundation is the root for your home. Apart from anchoring the house and providing a flat surface on which to lay floors and raise load-bearing walls, foundations also work as resistance against moisture, insects, fungus, soil gases and the immense pressure the soil itself applies.

The first step is to understand what kind of a foundation would work for your home. There are a number of options, but the variable factor is the soil structure and location of the project. The best soil type for a foundation is sandy or gravelly, which makes things a lot easier for builders. A lot of clay in the soil poses problems and calls for a different kind of foundation. Water tables, bedrock and old dumps can cause further complications, and these are important aspects that need to be checked out before you choose a suitable foundation. Also make sure you include the weather in your checklist because if you live in a very cold place, a foundation that incorporates a basement would make sense to avoid the frost.

Concrete Foundations:  Slab, Crawlspace and Basement Type

The most traditional and tested foundations use concrete. They are of three kinds: slab, crawlspace and the basement type. Each has its advantages and disadvantages but they are all are strong, durable and hassle free. The concrete slab foundation is poured directly on the grade and it is most suitable in places that have a high water table. A basement type would not be suitable in the above case because going as deep as 10 feet may maroon you next to a subterranean waterway. Ideally, monolithic slabs are used in houses built in areas with warmer climates. Crawlspace foundations are good for places with a lot of clay in the soil. The crawlspace provides a gap between the soil and the base of the first floor, which can be utilized for plumbing, electrical and other mechanical fittings. Both the slab and crawlspace varieties are obviously cheaper than a full basement. But it is difficult to work in the cramped crawlspace and the basement offers extra room and space if you need to put utilities such as boilers and generators.

Stem Wall or Monolithic Slabs

If you live by the ocean and expect floods, high water, or storms, then stem wall foundations are a consideration. Monolithic concrete slabs can sometimes be lifted off due to high winds, or water and waves swirling at their base. The stem walls assist in holding down the concrete slabs by attaching them securely to the ground and maintaining structural stability. Stem walls are a combination of cinder blocks, steel and concrete. They work well because they form a seamless unit with the slab, foundation and the walls. No water is allowed to leak in and make the structure weak. Water tends to move around the foundation and can in no way lift it up.

Steel, Concrete or Wood Pilings

Apart from stem walls, in areas prone to flooding, homes need to be elevated above the flood level. In such cases builders use either steel, concrete or wood pilings. Pilings work well in marshy soil too. Here, columns are driven deep into the ground so that they form an anchor. Wood pilings use specially treated timber called ‘permanent wood’ which is rot and termite proof and is similar to the ones used in wooden foundations. Permanent wood foundations that incorporate a basement have high insulation properties and are ideal in cold places. The only problem with wood is that there is always a fear of it rotting or being attacked by insects.

Depending on your needs and budget choosing the right foundation is the first step towards a safe home. At the end of the day a contractor and an engineer would be required to study and suggest the best options for you. With new technologies cropping up all the time, the homebuilder has a multitude of choices ranging from the traditional to the most recent, such as post and pier techniques and frost protected slabs, which are energy efficient and cost effective.