Since this is being tracked in from the outside, it is most noticeable near the entry areas. This is most common after repaving or sealing the asphalt, especially in the summer with elevated temperatures.
Jennite® J-16 driveway sealer causes less problem than other asphalt coatings.
This problem is most commonly a problem on blue and light gray carpet.
Yellowing from asphalt track-in is virtually impossible to remove. Asphalt coating and sealers are coal tar based materials, which are yellow when highly diluted in solvent. Unfortunately, the solvents required to totally remove these materials are also strong enough to delaminate the carpet.
Whenever a customer asks for your advice on replacing carpet and has a parking lot, advise him or her to avoid blue and light gray.
If not removed when fresh, yellow stain from asphalt and tar from parking lots and driveways is nearly impossible to completely remove without delaminating the carpet.
For small areas, apply a bead of the Pro-Solve Gel Spot and Stain Remover to the area to be treated, agitate, apply a bead of Power Gel, agitate with a Carpet Shark Spotting Tool and extract.
For large areas, prespray with TLS®® 2000, agitate, and extract at high temperature and high pH preferably with PCA™ Formula 4 or Super LCA™ followed with a Brown Out® rinse through the base unit - be sure to neutralize the tank with cleaning solution afterward.
If this fails, pre-spray with Citrus APS™ Spotter and clean.
Advise the customer to use adequate walk off mats which are exchanged or cleaned at least weekly.
For dried road tar, be sure to cut up the tar into small pieces first using Duckbill Napping Shears.