Builders and consumers can choose from a number of foundation options. In the late 1970s and early 1980s, wood basements gained popularity, reaching a national high in 1982 in terms of new home construction starts before builder and consumer concerns about poor fire wall ratings, poor construction techniques, rodent, termite and fungi damage, and the possible toxic effects of arsenic and other preservatives used with wood foundation systems led to a major decline in popularity.
In the late 1980s, stay-in-place expanded polystyrene wall forms (EPS) hit the market, providing insulation values of approximately R-20 before finish materials are applied, and they are slowly gaining acceptance and market share.
The foundations most often compared and debated for new home construction are hollow core masonry block basements and poured concrete foundation walls, which share some of the same features and benefits:
- Low maintenance
- Fire resistant
- Affordable
- Produced by local craftsmen using local materials
- Can be customized to produce decorative effects
- Can be customized to provide additional insulation values
Foundation walls serve three functions for builders and consumers.
- Support the above-ground structure
- Retain the soil surrounding the basement area
- Frame economical additional storage and living space for consumers
Keeping these functions in mind and moving beyond the marketing hype and rhetoric - poured concrete foundation walls out perform hollow core masonry foundations in four key areas:
Strength:
Poured concrete foundation walls are stronger than hollow core masonry foundation walls.
Poured concrete foundation walls have ultimate flexural strengths many times greater than hollow core masonry foundation walls to resist the pressures of earth, wind, and water.
Poured concrete foundation walls have ultimate compressive strengths many times greater than hollow core masonry foundation walls to support vertical building loads.
National building codes require hollow core masonry foundation walls to be reinforced with vertical steel when holding back unbalanced fill, if the fill exceeds 3'9" above the basement floor. Non-reinforced, poured concrete foundation walls exceed national building code standards for full-height fill by a large safety factor.
Builders and consumers get 40% more concrete, dollar for dollar, in a poured concrete foundation wall. More concrete means a stronger, denser foundation with fewer pores or seams for water to seep through, and less call backs for the builder.
Speed of Construction
Poured concrete foundation walls take less time to construct than hollow core masonry foundation walls. Time is money, and the quicker a builder can begin "roughing in," the more money he/ she saves.
Construction on Marginal Lands
Poured concrete foundation walls provide the structural integrity necessary to bridge "soft" zones on "marginal lands," saving the builder and consumer time and money when construction takes place on fill or poor soil conditions.
Year-round Construction
Technological advances in concrete admixtures provide quality control for poured concrete foundation walls constructed in inclement weather or freezing temperatures. Year-round construction allows builders to minimize backlogs and maximize cash flow.
Still not convinced poured concrete foundation walls are best'? Check out this statistic from a survey conducted by the Portland Cement Association (PCA), a national association of cement producers and suppliers who support both the hollow core masonry and ready mixed concrete industries:
"Poured concrete foundation walls dominate the national market, with 72% of new homes with full basements choosing poured concrete foundation wall systems. Concrete block holds 25% of this national market."
Beyond the rhetoric, poured concrete foundation walls are best for builders because they are stronger, go in quicker, can be built on marginal lands, and can be constructed year-round.
Nationally, seven out of ten builders choose to build new homes with full basements on poured concrete foundation walls. You should, too. |