“The results of the CFA’s study, based on engineering analysis, shows that unreinforced, hollow-core, concrete-block basement walls for residential construction, are not nearly as strong as solid poured walls. When compared to block construction, a poured concrete wall goes up fast, increases productivity, and results in a superior basement time after time. Poured concrete walls provide builders and owners with stronger, drier, better basements. They offer performance that block walls simply can’t match, and they do it at a competitive price.”
“The comparison advantages do not end at hollow-core blocks. In order to provide similar structural performances, concrete-block walls must include vertical reinforcing and solid grouting of the hollow cores. Grouting and reinforcing the cores can improve the structural performance of concrete-block but at a considerable increase in cost.”
“Concrete-block walls have “built-in” weak points at each horizontal and vertical joint. A typical 8’ high by 10’ long section of wall has nearly 160 linear feet of weakened plane. Most cracks in concrete block walls occur at these joints. Any increase in stress along the vertical surface of the wall exposes these weakened areas.”
This comparison shows that poured concrete walls provide builders and owners with stronger, drier, better concrete basements. They offer performance that block walls simply can't match. Poured walls have a compressive and flexural strength several times that of block, and far beyond the required safety factor.
When it comes to below grade construction, hollow-core blocks don't stack up to poured concrete. The results of this study prove unreinforced hollow core concrete block basement walls for residential construction fail to meet standards of accepted engineering practices even in 10" and 12" wall thicknesses.