Stone Restoration

Restoring a white marble facade

The white marble exterior of a building in Houston, TX, was defaced with black spray paint that the expertise of a team from International Stoneworks was able to remove


by Jason Kamery


Located in downtown Houston, TX, a building clad in white marble was spray painted over a weekend. Jacqueline Tabbah and her team at International Stoneworks were called on a Monday morning to evaluate the damage.

“Before we do any job, we do an onsite evaluation,” said Tabbah. “We need to see what it looks like; how bad it is. We quickly got downtown and evaluated it. It was pretty sizeable. Obviously, we were able to schedule the job pretty quickly.”


Amerisink

After arriving downtown and inspecting the damage, a large amount of black spray paint on a honed marble surface, they were able to get to work right away. “The way you handle paint removal from stone has very specific steps you have to take,” said Tabbah. “We consulted with the Natural Stone Institute; they have a dimensional stone manual. The first thing was just cleaning it with a nylon brush and paint remover. Paint remover is more like a gel. We just gave it a once over with the brush and the gel. We cleaned that off and then did a sanding process. First, we used sandpaper that was about 120 grit. We followed up with a diamond-impregnated pad that was about 200 grit. The building has a very honed finished; it’s not a polished exterior. That was really all that it needed in terms of the honing. When you hone it, it also helps open the pores of the stone.”

Following the sanding and honing process comes one of the most important and time consuming steps of the process, applying a poultice. “We mixed the poultice with a compound called S.A.C., stain absorbing compound, as well as with the paint remover,” said Tabbah. “The way the poultice is applied is you mix the two together. They become a muddy substance. You apply it to the surface of the stained areas, then cover it with plastic, tape down the edges with blue tape and leave it overnight.

“We came back the next morning, cleaned it off and did an evaluation,” Tabbah went on to say. “We saw it was about 50% better, but it was not all gone. We applied a second application of the poultice. We left it there overnight, came back the next morning and started cleaning it off and it looked much better. So we removed the rest of the poultice with a pressure washer with a fan tip. It looked significantly better. Then within time, it has also faded as well. Whatever we were not able to remove, in time, you can’t see it anymore. You would drive by that building today and would never know.”


When it comes to the grout lines, Tabbah and her team use a grout brush to get into the dip. “During the first part of that paint removing process, we will use the nylon brush and also a nylon grout brush,” said Tabbah. “That helps get into the dip of the grout line. It’s a very important tool to have in your truck. A lot of our complaints are, ‘Our grout is dirty.’ It’s a huge complaint.”

When asked if time was of the essence on this project or projects like this, it generally wouldn’t have made a difference to Tabbah.

“If they had left it on for a week and not done anything, the process really wouldn’t have changed,” said Tabbah. “When it comes to stains and people call and say, ‘I have no idea how long this has been here. It could have been 10 years or so.’ We just don’t know how hard it will be to remove. The other factor about stains is if you know the source of the stains, you can maybe better determine how well it’s going to come out. Another example, we will sometimes see rust stains. It’s these stains that look more like brown orangey, yellow in color. When I see those stains, whatever type of floor it is, can be a residential bathroom or outside an exterior entry. These stains are very difficult to remove because they generally come from the bottom up of the tile. So, when it goes throughout the thickness of the tile, the poultice most likely doesn’t work. It tries to draw out the stain, but if it goes through the thickness of the tile, there is nothing really to pull out. For me, the difficult stains are when someone says, ‘I have no idea where this came from and I have no idea how long it has been here.’ So I say, ‘We can give it a go, but we just don’t know if it will come out or not.’”

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April 2021 | www.stoneworld.com