Poured concrete walls should be steel reinforced. When poured, the footing will have a V-shaped groove at the top with rebar from the footing- exposed to tie the wall steel. The concrete wall should be 8 inches thick and it should be poured in a single pour. The inspector will evaluate the condition of the concrete foundation and examine any cracks or other defects, signs of water seepage, etc. Any problems, severe or otherwise, will be brought to the attention of the buyer and recommendations made to correct these problems.
Concrete blocks, also referred to as concrete masonry units (CMU) are used as basement walls as well as retaining and crawl space walls. Regardless of the end use, a concrete block wall must have a supportable footing. A horizontal crack in a basement wall, even if it is only a hairline crack, can be the most significant crack observed and the most costly to repair. The inspector will carefully examine all visible foundation cracks and make recommendations depending on the severity of the crack. A significant crack may cause a wall to fail and be very costly to repair.
Brick foundations are usually seen in older homes. It is no longer cost effective to install brick foundations and this type of foundation is often not as durable compared to other modern installations such as poured concrete or cement block. A brick foundation is installed in much the same way that a solid brick house is built except it is below grade and should rest on a solid footing. It is not uncommon however that some of these foundations were not placed on footings and now may be settled badly. Brick foundations are inspected carefully for the particular defects that they are prone to such as, settling, water seepage and deterioration of the bricks themselves. Many brick foundations have been sealed with wire lathe and cement stucco giving them a look of a poured concrete foundation.
Stone foundations are usually seen in older homes. They were seldom used in construction dating after WW II. Stone foundations can be prone to settling and water seepage. A unique problem to stone foundations is that the foundation itself can be a source of Radon gas, which is an environmental hazard. This type of installation is also prone to such problems as settling and water seepage. A stone foundation when maintained well is a very aesthetically appealing installation, but must be inspected carefully. Joints wear quickly because they are usually not smooth and uniform. Shifting or settling can occur because of the uneven nature of stones.
Slab-on-grade foundation is used when the structure is built directly on the ground. Monolithic slab-on-grade foundations require a wide base and steel reinforcement. A floating slab is a reinforced slab placed between two walls and footings. Aside from the usual defects (cracking, seepage) the inspector will be looking for, slab foundations are more susceptible to termites and other insects. Slab homes are difficult to inspect because almost all of the entire structure is enclosed and not visible. Other areas will be inspected more carefully for indications of problems related to slab-type construction.