Wax has been absorbed into the concrete!

[sepani]

Anyone know how to remove the stain? The wife's friend wanted to surprise us and had placed a candle on our stairs. The candle capsized and this is what happened...

 

[Leif i Skåne]

Most likely it wasn't a stearin candle (which is animal-based) but a paraffin candle which is a petroleum product and unfortunately melts in sunlight.
To remove it, try using a degreasing agent, possibly with a pressure washer.
Or with heat + something absorbent like blotting paper.

Otherwise, you can "stearinfiera" the whole staircase so everything is covered with a homogeneous stain.

 

[raveper]

Place something absorbent and iron it on, and the worst might disappear. Then maybe some brushing can even it out.
But don't burn it as there's a risk it turns soot black instead.

 

[Krikkan]

I believe in something like coffee filter/paper towel and an iron (or other heat) and then scrub with regular dish soap.

 

[Staffan-N]

Did the same thing on a marble cafe table, the candles melted in the sun and seeped into the stone's porous structure. After a lot of rubbing with gasoline and trying to absorb with heat, I changed tactics and rubbed the entire table with paraffin oil instead...looked like new, and now a few years later, it has slowly regained its weathered appearance without the stains from the candles.

 

[sepani]

Did the same thing on a marble cafe table, the candles melted in the sun and ran into the stone's porous structure. After a lot of scrubbing with gasoline and trying to absorb with heat, I changed tactics and instead applied paraffin oil to the entire table... became like new, and now a few years later it has slowly regained its weathered appearance without the stains from the candles.

iron, coffee filter, sand and sandpaper became much better, completely