Considering Concrete Floors? 3 Green-Minded Questions to Ask
Concrete floors are becoming increasingly popular due to their versatility and durability. They can even reduce material consumption when an existing slab is utilized. If you are considering concrete floors for inside your home, there are three questions you can ask to make sure the concrete is a healthy choice for you and the planet.
1. What’s in the mix? When selecting a concrete mix, your construction team will factor in strength and performance specifications for the cured material. They may also consider sustainability factors, including whether to add coal fly ash to the mix.
There is some debate over the greenness of coal fly ash. Fly ash is a by-product of coal burning, and it contains heavy metals like lead and mercury. But when added to concrete mixes, it has several advantages, including that it increases recycled content and reduces the amount of Portland cement needed in the mix.
When not used in concrete, fly ash is disposed of either in landfills or in wet ash ponds, where it can leach into surface water and groundwater. Recently the Environmental Protection Agency (EPA) came out in favor of recycling the material through use in concrete.
Some environmentalists are eager to encapsulate the fly ash inside concrete; theoretically leaching rates would be much lower than through traditional disposal means. Proponents of fly ash recycling also point out that it reduces the amount of Portland cement needed in concrete. Portland cement is a very energy- and carbon-intensive product to produce, so some argue that fly ash therefore reduces the carbon footprint of the entire concrete mix.
Yet there are fly ash skeptics in the green building community, too. For one, the carbon footprint of coal fly ash may in fact be higher than that of Portland cement, when calculations include the carbon released from burning coal. When the full life cycle of fly ash is taken into account, it shakes the argument that the carbon footprint of a concrete mix is in fact lowered through its use.
In addition, because fly ash is a hazardous material, some wonder whether it renders the concrete hazardous too, during both use and disposal. The main concern is whether the fly ash leaches heavy metals after the concrete cures, introducing these toxic substances into homes. Finally, some environmentalists argue that green builders are buying into the coal industry’s efforts to rebrand hazardous waste as recycled material.
Read Considering Concrete Floors? 3 Green-Minded Questions to Ask
Considering Concrete Floors? 3 Green-Minded Questions to Ask
