Surface Moisture
The presence of moisture on the pavement surface prior to marking placement will likely have a negative effect on the bond formed between the pavement marking and the pavement surface. The presence of moisture on the pavement should be checked whenever conditions are questionable. Presence of pavement surface moisture can be determined using either of the following two methods in accordance with TxDOT Specification Item
- Asphalt or Concrete Surfaces— Place a 12×12 inch square piece of plastic wrap on the pavement surface using duct tape to affix the edges. Let stand approximately 15 minutes and check for moisture bubbles on the inside surface of the plastic. If moisture bubbles on the plastic are larger than a pencil eraser, then the pavement contains too much excess water. Notify the contractor of this condition and postpone all marking operation until the pavement is dry enough to prevent the large moisture bubbles from forming on the plastic.
- Thermoplastic Applications on Asphalt Only— Using roofing felt paper, place a 12×12 inch square of felt on the asphalt and install the thermoplastic material directly onto the felt paper. Let it cool for approximately 10 seconds, then lift the paper to check for moisture on the back side. If moisture bubbles larger than a pencil eraser are present on the backside of the roofing paper, then the pavement contains too much excess water. Notify the contractor of this condition and postpone all marking operations until the pavement is dry enough to prevent the large moisture bubbles from forming on the back of the felt paper.