Concrete/Foundation

Concrete forms the foundation of most homes. While it's not visible, it is often the largest volume construction material you use.  Using the right concrete costs very little more, and helps ensure a healthier home. 

 

Extra Cost: <$100  Healthier concrete is almost the same cost as less healthy concrete, and it finishes better!      


What: Don’t use any fly ash or any other admix in your concrete.  Just use water, sand, and Portland cement. 


Why: Lots of nasty stuff gets added to concrete.  Fly ash in particular is bad for your health. Admixtures evaporate from the concrete over time and eventually waft up into your house.  These chemicals pass right through cracks in your floor that you cannot see with your naked eye.2


How: Any concrete company can do this so don’t let your contractor tell you fly ash and admixes can’t be left out.  Fly ash it just a filler.  Plus, concrete without fly ash often ends up smoother and stronger, so its simply better all around.


Extra Credit:

Concrete is like a sponge – it readily sucks up water and spreads it around.  Water in concrete evaporates into your floors and walls and creates mold.3 So proper waterproofing is also very important to building a healthy home.  The key elements are:  have at least 6 inches of good drain rock below and on the sides of your foundation, have a good, thick (>10mil) vapor barrier taped thoroughly at every seam, and waterproof the sides of the concrete all the way up above the ground. Finally, make sure that when your landscape irrigation system is put in, none of the sprinklers are hitting the concrete.


References

1.  http://rns.trb.org/dproject.asp?n=12636

2. http://www.epa.gov/climatechange/waste/downloads/Fly%20Ash.pdf

3. http://www.epa.gov/iedmold1/pdfs/moldguide.pdf




 
All seams in vapor barrier taped to prevent gas and water intrusion
High mill vapor barrier over 6 inches of drain rock
Concrete samples from every concrete truck in case I needed to test and ensure I was getting the healthy concrete I’d ordered.
Smooth concrete finish