In the foundation industry, the cinder block foundations versus poured concrete debate is rages on. It is hard to say which one is better; however, most builders choose poured walls for new homes. According to a survey by the Portland Cement Association, 72% of new homes with full basements are built with poured concrete wall systems while concrete block walls hold 25% of the national market. Each type has its advantages and drawbacks.
Poured Concrete Foundations
Poured concrete wall foundations are arguably stronger than cinder blocks. Poured walls have a better lateral strength, which means they are able to resist more pressure from the water and the soil from the outside. A poured wall doesn’t have joints like a block wall so it is easier to waterproof. Poured walls tend to be the preferred choice of new construction builders. Poured walls can be formed in any foundation design and can be adapted for last minute changes. It is faster and more efficient to construct a poured wall but can be expensive if the cement plant is far away. If the concrete truck has to travel farther than 90 minutes, a cinder block wall foundation would probably be the better choice. It really depends on the circumstance, availability of concrete and skilled workers.
Cinder Block Foundations
Prior to the 1970s, cinder block foundations were the norm. Nearly every house was built with a masonry foundation. While the poured wall wins for lateral strength, the cinder block wall built correctly beats out poured wall for compression strength. Meaning it can hold more weight on top of the foundation. For this reason, a cinder block wall foundation is often the choice of engineers and architects. A good block wall does need skilled bricklayers translating into more labor costs. Plus skilled masons are hard to come by. Block wall foundations are more prone to bowing and buckling and repairs are costly if you have to rebuild the block wall. While both foundation types can be completely waterproofed, block walls tend to have more leaks because of the grout lines. Water and weather wears down the mortar over time and causes leaks.
Both types can also be reinforced with steel rebar. This helps strengthen any type of foundation. One benefit of a concrete block wall is that the concrete is already solid at time of construction. Poured walls have to cure onsite and sometimes can lose some strength in the process if spalling occurs.
No matter which type of foundation you decide make sure you install a proper waterproofing system. No foundation wall will be any good if it isn’t waterproofed.