Remove cement from paving stone

[ChrisCornell]

I have laid about 40 sqm of paving stones, a yellow-tinted tumbled stone, outside the house.

When I grouted with joint sand (i.e., swept it down), I mixed in 25 percent standard cement (1 part cement, 3 parts joint sand) and swept it down. Unfortunately, the weather changed and it became a bit humid during completion, and it rained all day after, so only today am I seeing the result. Several stones have become gray from the cement.

Does anyone know how to remove this gray cement surface from the paving stones? I don't know how deep the cement has penetrated into the stone, but it has at least burned on.

Hydrochloric acid? Is it something one dares to try? Or will it also destroy the paving stones and their yellow color?

 

[Erik Salhammar]

One should not joint with cement. The surface settles over several years, so you need something more flexible. There are epoxy-based products that seem to work well. But I advocate for stenmjöl. It washes away over time but can be replenished. Then the surface can settle as it wants, and if the slope is correct, the water will run off and the settling will be even.

 

[ChrisCornell]

Thanks for the response, nine years later

The problem is solved, and it actually went quite well with 25 percent cement in the sand. It still looks nice.

 

[raulll_78]

Have laid about 40 square meters of paving stones, a yellowish tumbled stone, outside the house.

When I jointed with joint sand (i.e., swept down), I mixed in 25 percent standard cement (1 part cement, 3 parts joint sand) and swept down. Unfortunately, the weather turned, and it got a bit damp during completion and rained all day after, so only today do I see the result. Several stones have become gray from the cement.

Does anyone know how to remove this gray cement surface from the paving stones? I don't know how deep the cement has penetrated into the stone, but it has at least burned in.

Hydrochloric acid? Is it something to dare trying? Or will it perhaps also destroy the paving stones and their yellow color?

Hi. I have the same problem. How did you fix the problem?

 

[ChrisCornell]

Hi. I have the same problem. How did you fix the problem?

Hi,
It wore off over time, it went pretty quickly.