Epoxy troubleshooting - hot tyre pick-up
Have you ever seen a garage floor coating lift right where a car was parked?
You might not see it on all tyres; you might not even see it the first few times the car parks on the garage floor. If it does happen though, it could be a case of the dreaded hot tyre pick-up and it more than likely had something to do with a few common causes.
Hot tyres and garage floor problems
The reasons why garage floors can lift under a tyre are -
- The preparation of the concrete was poor and laitance was not removed properly before coating. It takes very little effort to fail a coating on a poorly prepared slab.
- The garage floor coating was applied onto a previously uncovered slab with oil or silicone contamination (over-spray from silicone “tyre shine” products is a common source of silicone contamination). If there was such contamination on the concrete then typically crawling would’ve been seen after basecoat application.
- The basecoat was a single-pack product with low crosslink density and poor heat resistance. When the hot tyre parked on top, the heat transfer softened the film and made it easier to peel off.
- The basecoat may have been a two-pack water-based product, but it didn’t crosslink fully and resulted in a porous, relatively weak film. This can happen if the product is applied too thick and starts to crosslink before the water has evaporated out of the system.
The typical scenario
With these common reasons explained, you can probably now piece together what usually takes place in hot tyre pick-up situations. Firstly, the garage floor coating was probably applied without properly cleaning the slab or thoroughly preparing the surface beforehand. The product used was also pretty cheap and put down by an inexperienced set of hands without closely observing all the instructions. The finish looked ok, however when it came in contact with hot tyres the heat softened the film and created a peeling stress that pulled it off once the tyres had cooled.
Stop coatings from peeling
So there’s the typical problem in a nutshell, but how do you overcome it? In light of what I’ve said about the causes, doing the following three things would be a good start -
- Do water bead tests to check if there’s any contamination before commencing the coating process. Remove the contamination first and then thoroughly prepare the surface to establish a profile for the garage floor coating to grab onto.
- I favour two-pack epoxy products as the basecoat because they tend to have greater overall durability. In addition, I favour two-pack solventless epoxy products because I don’t like solvents inside and if it’s moisture tolerant as well then I minimise my risk of other curing problems.
- Finally, use the products as recommended by the manufacturer, paying particular attention to the curing conditions, film thicknesses etc.
To finish, the best example I ever heard of hot tyre pick-up was a water-based epoxy product used in a garage that didn’t pull off in a large chunk, but rather a very neat-looking tread pattern! It was an amazing thing to see, although I doubt the owner would’ve been so thrilled!
What other classic garage floor problems have you come across?
Take care and keep smiling,