Pouring the basement floor

We are getting our new concrete floor! This is our big day after months of preparation and research.

The research was not only about the technical aspects of moisture management and how best to insulate, it also involved logistical questions, i.e. how do we get 21 cubic yards of concrete down into the basement.

There is really no good way to get the concrete directly from the truck to where we need it. We could get the chute of the truck to the very back of the basement, but how would we get all that concrete to the front?

Using wheelbarrows, such as for the spread footings, is not an option unless I am willing to spend several days on the pour. I was thinking of using 20 foot long portable conveyor belts. But how would I maneuver them in and out of the basement?

Pumping the concrete is my best option, as I had been told a number of times, and slowly came to accept. I could not find an equipment rental place that had small, trailer mounted pumps, but found a company with a small truck mounted pump that came with an operator.

concrete-pump-01

We can’t just pour any type of concrete into the pump, but need what is called a ‘pump mix’. It means that the concrete comes without air (concrete is often air entrained) and is a little lower on the stone content.

concrete-pump-02

I ordered and scheduled the pump mix a couple of days in advance. We set up the pump, the concrete arrived right on time and we were ready to go.

Oh boy, time can fly! We had three truck deliveries, spaced 20 minutes apart. We pumped and poured like there was no tomorrow. While pouring, we spread the concrete to a rough elevation.

When a large enough section was filled, Neil and Greg, the finishers, screened the fresh concrete to the finished elevation. Sort of like I screened the gravel base, but this was going much faster!

Once done, we took a little break to let the concrete set. Not for too long, because Neil had to go back to the front and start with the expansion joints while the concrete was still fresh enough.

expansion-joint-01

While Neil was taking care of the joints, Greg fired up the troweling machine to add the finishing touches to the floor, except for odd corners, which required hand troweling.

It was a long day, be we are sure glad to have this milestone behind us!

About Marcus de la fleur

Marcus is a Registered Landscape Architect with a horticultural degree from the School of Horticulture at the Royal Botanic Gardens, Kew, and a Masters in Landscape Architecture from the University of Sheffield, UK. He developed a landscape based sustainable pilot project at 168 Elm Ave. in 2002, and has expanded his skill set to building science. Starting in 2009, Marcus applied the newly acquired expertise to the deep energy retrofit of his 100+ year old home in Chicago.

2 thoughts on “Pouring the basement floor

  1. Marcus – the welded wire fabric (w.w.f) mesh should ideally be placed in the upper third of the concrete slab. Our typical details show the wwf placed on “chairs” to insure that its located it at the correct elevation in the slab. Unfortunately the “chairs” are often omitted and I’m told that the wwf is pulled up into the slab (hopefully to the correct height) just after the concrete has been placed. Is this what occurred on your project?

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