The primary
purpose of the foundation is to support the structure of the home.
Foundations will vary in type depending on the age of the home and often the
area of the country it is located. Many older homes have stone
foundations. Newer homes may have poured concrete or block foundations.
There are also less frequently constructed types of foundations such as wood
foundations. What is important to be concluded by the inspection is,
whether or not the foundation is adequately supporting the house and shows
no deficiencies that would create a significant potential for failure.
Some things in the construction of a foundation cannot be observed and
therefore most often cannot be inspected. Any modern foundation should
have a footing. A footing is typically a poured concrete slab about
ten to twelve inches think and twice the width of the foundation wall (see
diagram below to the left). The footing provides a good base for the
more narrow foundation wall to rest on and prevent settlement into the
ground from the weight of the structure. The footing should be
installed deep enough into the ground to provided frost cover. Freezing ground expands. If the footing is not
installed deep enough then the ground can freeze under it. This creates the
potential for movement and damage to the foundation and structure. Stone
foundations are typically thicker, do not have a footing and are more
susceptible to seepage from ground water due to the lack of modern waterproofing
methods applied during construction.
If a foundation is
adequately sized for the structure, the next important thing to determine is
its condition. Cracks, bulges or leaning foundations can have
little or no structural effect or very significant structural effect.
If the condition appears like a significant structural issue, the home
inspector will advise further evaluation by an engineer and/or foundation
contractor to determine the best corrective course of action. Many
foundations have some cracking from normal settlement and corrective actions
may not be warranted because they usually do not worsen over time. In
this case monitoring is recommended to ensure the cracks do not worsen. Similar
principles apply to other deficiencies
such as slight leaning or bulges in foundation walls. Beside the
structural importance of cracks, water seepage can also be a factor - see
"Basement Moisture".
