Masonry Magazine September 1972 Page. 19
NCMA-TEK
An Information series from National Concrete Masonry Association
WID
Concrete Masonry
Foundation Walls
43
Introduction
Concrete masonry units have for many years offered a number of advantages in building foundation walls. They are relatively fast to construct and low in cost. Because block are always available and because the block mason can readily adapt to unusal configurations or other special requirements of any job it is usually possible to complete the work in a short time.
Good block walls are high in quality, providing low thermal conductivity and good acoustical properties. Where thermal requirements can be satisfied without furring, the wall may need no further interior treatment except possible painting.
More often than not it is economical to take advantage of the foundation wall to enclose basement space. Except where soils are extremely tight or badly drained, basements usually provide the cheapest enclosed living space that can be obtained in residences. A basement can also be used to save outdoor lot space by providing some of the same indoor space that would otherwise create a more sprawling basementless house. A basement may be used to provide room that might not otherwise have been available for recreation, garage space, cool storage, and easy access to plumbing lines and heating ducts.
Public and commercial buildings also profit from having basements. Usually it requires only an additional two- to six-foot depth of foundation wall to provide basement space that in a commercial building may provide additional income directly or indirectly.
TABLE 1
Minimum thickness of foundation walls with unbalanced fill
| Kind of Block | Minimum Nominal Wall Thickness. in. | Maximum Height of Unbalanced Fill, ft When Wood Superstructure is Used | When Masonry or Masonry Veneer Superstructure is Used |
|---|---|---|---|
| Hollow ASTM C 90 | 8 | 5 | 5 |
| | 10 | 6 | 7 |
| | 12 | 7 | 7 |
| Solid ASTM C 145 | 8 | 5 | 5 |
| | 10 | 7 | 7 |
| | 12 | 7 | 7 |
TEK 43 © 1972 National Concrete Masonry Association
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