Installation of the basement concrete floor using a concrete boom truck.

On a Monday in early June, while the heat index was slated to reach 114 degrees, the concrete basement in the Green & Main building at 800 19^th Street was poured by Rick Hogan Construction. The construction team brought in the concrete boom truck and positioned it to allow best access to the basement.

Extra challenges encountered were not due solely to the heat, but to pouring a basement inside an already existing building – which created a couple of logistic challenges – but nothing that long pipes and hoses could not address.

Looking down into the basement opening from atop the basement wall of the addition.

The layers of the basement floor are very specific. First, there is earth. Next comes 6 inches of 1 inch river rock followed by 2 inches of styrofoam. On top of the styrofoam is a layer of polystyrene which is followed by another inch of styrofoam. The icing on the basement cake is 5 inches of concrete. This concrete mixture is composed of crushed glass, fly ash and slag – all recycled products. Finally, there is a bentonite strip that is placed around the internal edges where the floor meets the wall to help with waterproofing.

One additional component to the concrete mixture is microfiber. Microfiber helps to reduce shrinkage cracks, and in the heat of an Iowa summer, helps to slow the process of drying when the high noon sun is beating down on the freshly laid concrete.

Rick Hogan, owner of Rick Hogan Construction.

An interesting side note is that Rick Hogan, who owns the company, worked for a Pepsi distributor when he was 18, having grown up on the west side of Des Moines. He made multiple deliveries to this building when it was H&H Grocery, getting to know the owner a little bit. As time and choice would have it, Rick returned to this site, contributing to its ongoing historical narrative through his construction contributions.

For additional photos of the basement concrete flooring process, please see our photo gallery.

– Jean Danielson is director of operations for Indigo Dawn. She believes in a free lunch and the tooth fairy.