92) Acid-stained concrete

by Gail on August 26, 2010

We’re leaving the basement floor finished as concrete. After curing for a few months, we had the floor sanded to take the paint/stains/construction glue off. It did not really smooth the finish that much. However, we decided to add some warmth to the finish by acid-etching the concrete. This only works on clean concrete.

The materials and help came from StarPatch in Burnaby.

The first sample in a closet. Note the staining on the wall. This is a 1:1 concentration of copper, with a full concentration of terra cotta on top. We decided it was too dark.

The first sample in a closet. Note the staining on the wall. This is a 1:1 concentration of copper first, with a full concentration of terra cotta on top. We decided it was too dark.

So I tried a full concentration of copper, and masked off the wall first. This was better.

So I tried a full concentration of copper in another closet, and masked off the wall first. This was better.

After cleaning, walls were masked.

After cleaning, all the walls were masked.

Copper is sprayed on.

Copper is sprayed on, full strength.

Terra cotta is sprayed on along the grid lines. It is the acid yellow colour when it first goes on.

Terra cotta is sprayed on along the grid lines. It is the acid yellow colour when it first goes on.

Drying/the acid reaction requires at least 4 hours. I left it overnight. Then, the chemistry is brought to neutral with the application of baking soda water. The floor is mopped and flooded about 10 times until the rinse water runs clear.

Drying/the acid reaction requires at least 4 hours. I left it overnight. Then, the chemistry is brought to neutral with the application of baking soda water. The floor is mopped and flooded about 10 times until the rinse water runs clear.

a view of the gridded floor

a view of the gridded floor

The bedroom just has copper, with a bit of terra cotta around the edge, no grid.

The bedroom just has copper, with a bit of terra cotta around the edge, no grid. After the staining is thoroughly cleaned/rinsed off and dried, water-based acrylic sealer is applied. It intensifies the colour.

{ 2 comments… read them below or add one }

Joy August 26, 2010 at 3:43 pm

Stunning finish on the cement floor. You are so brave/creative Gail.

Janet Armstrong August 28, 2010 at 10:11 am

Having seen this in real life, I can attest to its attractiveness. Well worth the work!

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