Sunday, April 19, 2009

Placing the Concrete Fireplace Surround

It has been a very productive weekend so far. We are getting ready to go for a run so I figured a post just for yesterday's big project was appropriate. We got the concrete fireplace surround placed yesterday. I have spent the last couple weeks after work tweaking a concrete fireplace mixture based off of quikcrete.

The before picture with the reinforcement set aside and cardboard down to protect everything.

Now this is a setup. Due to the small size of the mixer, or the large size of the fireplace, I had to do two separate mixtures which makes the logistics interesting. The concrete is based off of quikcrete but I made it stronger and lower shrinkage using various chemical admixtures. It is handy to know the right people. The concrete is black so I had to buy some pigment. The smallest amount of pigment I could buy was for 1 cubic yard of concrete. Since the fireplace is 3 cubic feet, I have lots left. If you need any black concrete objects let me know and I will make you a deal.

Look at those rippling bi-ceps. Our neighbor Mark knows where I can get a 5 cubic foot (this one can only mix about 1.5 cf) gas powered mixer for cheap. Hopefully for the rest of the summer projects we will have more mixing capacity. I can't wait to be placing concrete outside or into more normal shapes.

The black pigment is carbon-based and sucks up the water reducer. By the second half of each load things were getting a little stiff. Normally a vibrator takes care of this but it made too much of a mess to continue using inside.

The forms stayed put and everything finished nice. I hard troweled the top so it should be smooth. Now we have to wait and see how well I got the concrete consolidated down the sides of the form. There wasn't a whole lot of clearance and I might have to fill some honeycombing. Good thing I have lots of leftover materials. Here it is covered with plastic to lock in the freshness.

Wet towels to keep the moisture in. Like the sink this was towards the more difficult end of home concrete projects. Although I didn't make too much of a mess. Really other than my hands stained black for the next week, things look pretty good.

No comments: