The Mystery of Yellow Discolorations.
"Why is my vinyl turning yellow?" asked a commercial customer by Fletcher near Avila. The customer's Armstrong vinyl composition tile (VCT) was only a few months old. We provided the initial stripping and finishing of the VCT after the installation. Our coats of polish left the VCT shining. Well, we instantly had a suspicion of the cause, but a visit to the store was warranted.
Inspection and Testing.
The store owner correctly observed that his resilient flooring was turning yellow. The discoloration followed the walk patterns of his patrons. But, why? We identified the entrance as the worst area, which was next to the checkout counter. The worst area is the best area for testing.
Success! The yellow disappeared after a minor rubbing with a little mineral spirits and a soft scrubbing pad. We were also able to remove the yellowing (to a lesser degree) with water and a paper towel.
As is apparent in the image above, we created a clean area. Notice that the vinyl possessed a perfect, bright color next to the counter, and notice how the yellowing increased with the increase of foot traffic away from the counter. Evidence of the root cause was mounding.
We removed the entrance mat to, again, see that a protected area retained clear color. The yellowing began at the edge of the mat. The cause of the yellowing corresponded to the foot traffic.
New Exterior Ruins New Interior.
But, why? Four months earlier, the color was perfect. Conversation with our customer and with one of his neighboring tenants revealed that the plaza's entire parking lot was recoated with fresh asphalt shortly after the new VCT was installed. The parking lot's blacktop had very high traction (unlike old asphalt). CONCLUSION: Asphalt residue was being tracked into the store from the parking lot. The new exterior was ruining the new interior.
Resilient Manufacturers Know and Offer Solutions.
Although the cause was a surprise to our customer, the cause matched our original suspicion and matched the warnings of resilient flooring manufacturers. Two problems are created by new asphalt. First, stickiness can be transferred to your flooring, which causes the floor to accumulate dirt more quickly. Second, yellowing is caused by chemicals in the asphalt, which, if left unattended, can cause a permanent discoloration.
Yellow discolorations develop slowly by the transfer of trace amounts of asphalt residue through the accumulation of thousands of footsteps.
"Antioxidants used in the manufacture of rubber and petroleum from exterior asphalt sealants and/or spills tracked in on shoes and casters may cause permanent discoloration to any resilient floor. The stain gradually appears over time." ---Armstrong
Warranty limits can be revealing, as in the case of Mohawk's Master Resilient Warranty:
Exclusions: "Discoloration from underlayment panels, mold or mildew, rubber backed mats, asphalt or deicer tracking."
Other flooring manufacturers warn of the same risk of yellow discolorations caused by tar, asphalt, or petroleum byproducts.
Different Tenant. Same Yellowing.
To finalize our conclusion, we needed to investigate from one more angle. The general store that we inspected was one of about ten lessees in a strip plaza. If the yellowing was caused by the newly resurfaced blacktop, then yellow discolorations should be developing in the resilient flooring of other stores. A major department store, with a weekly vinyl maintenance program, was located about three units away in the same shopping plaza. The findings were conclusive.
Again, the vinyl flooring beside the counter was clear and clean. Notice the gradual contrast that developed from the left side to the right side.
Yellowing that is caused by asphalt, tar, or other petroleum byproducts can usually be removed if addressed in a timely manner. Follow the cleaning instructions published by the manufacturer of your vinyl, vinyl composition, linoleum, or rubber flooring. Generally, start by using a neutral or resilient floor cleaner and a nonabrasive scrubbing pad (equivalent to or a 3M™ White Super Polish Pad 4100). (Linoleum requires more carefully applied maintenance efforts, which are provided by the manufacturer.)
Armstrong offers the following instructions if a general cleaner fails to remove the yellowing:
"Remove tough spots like shoe polish, tar and asphalt driveway seal with adhesive cleaner, low-odor mineral spirits or nail polish remover containing acetone (follow instructions on label), then wipe with a damp cloth." ---Armstrong
In addition to mineral spirits, you can also use turpentine or rubbing alcohol (a.k.a, isopropyl alcohol). Thoroughly remove any solvent residue. (If aggressive cleaning agents or aggressive scrubbing is required, the vinyl finish or VCT wax will be removed or reduced, which will require new applications of wax or polish.)
Prevention is better than correction. Flooring manufacturers offer four specific ways to prevent yellowing from tar, asphalt, and other petroleum byproducts.
First, Mannington Flooring advises that the source of the problem be contained.
The Mohawk Group makes the same recommendation:
"To eliminate staining from asphalt tracking, we recommend the use of a latex-based driveway sealer." ---The Mohawk Group
Sealing all of the asphalt may not be realistic. An inexpensive suggestion by the Mohawk Groups will help:
"Place transition mats at exterior entrances to prevent dirt, asphalt sealers and de-icers from being tracked onto your floor." ---The Mohawk Group
A mat should be placed inside and outside of each entrance. But, as we observe from the case that prompted this blog posting, a mat alone cannot prevent discolorations. Therefore, the third recommendation is the most important way to prevent permanent discolorations.
"The use of a polish/finish will help minimize these types of stains." ---Armstrong
Our fourth and last recommendation returns to the topic of correction. Make sure that routine cleaning maintenance is performed. Although regular cleaning does wear away the wax or polish at a faster rate, proper cleaning helps to prevent permanent yellow discolorations and prevents the need for solvent-based cleaners.
Other Flooring Products.
Least there be any misunderstanding, tar or asphalt can permanently discolor most flooring products, including hardwood, carpet, stone, laminate, etc. We offer specific warnings under our maintenance pages for most, if not all, flooring types. Thankfully, some sheet vinyls and vinyl tiles available today come with the specific guarantee that exposure to asphalt driveway sealer will not permanently stain the flooring.