Removing Yellow Discoloration on Terrazzo Caused by Carpet

When carpet is removed from terrazzo, it often leaves behind a large yellowed area the shape of the carpet. This is common problem with carpets that have jute or rubber backings. Moisture becomes trapped under the carpet and causes the dye in the backing to bleed into the terrazzo. To remove the yellow stain, clean the area throughly with a good detergent, and then poultice with a 20-50% hydrogen peroxide solution and diatomaceous earth. Several poultices may be required to remove the discoloration. If the carpet remained on the floor for a very long time the stain may never completely disappear.

TIP It may also help to hone the terrazzo before applying the poultice. Many terrazzo floors have waxes and honing will remove any wax coatings as well as opening the pores so the peroxide can penetrate.