What is the general consensus regarding ventilation in an ICF crawlspace? The code requires crawlspace ventilation, but envelope insulation negates the need to ventilate. What have others done to address the code requirement and what is the best practice?

The recommendation today is to seal the crawl space, but to do so you will have to seal the floor and all vents. There are companies today sealing up crawl spaces with heavy mill plastic, installing a sump pump and putting in a dehumidifier which eliminates all mold in the crawl spaces. It's a tough sell to some building departments.

Where are you building?  I build ICF homes in NC and would never consider ventilating a crawl space.  Fortunately, NC has adopted a closed crawl space addendum to their building code.  In states where there is no code, get an engineer to seal your plans (with the closed crawl design).  Once an engineer has sealed it, the building department will (generally speaking) yield to the engineer since they are then taking the liability.

Go to crawlspaces.org for design of closed crawl systems.  You have to be careful what equipment (if any) you put in the crawl, as well as supply air and drainage to control moisture.

Oakley, sent you an IM.  Let me know what part of NC you are in.  I plan on building just outside of charlotte this fall, and am entertaining the idea of an ICF crawlspace, or possibly the entire thing with the new energy efficient mortgage programs now.  I have only found one ICF contractor in this area....

Kenny     [email protected]