A superior moisture barrier,
which increases durability and reduces
floor maintenance costs

Especially in climates with extreme weather conditions, water-based paint systems currently used to protect the underside of trailer floors can break down when subjected to intense water spray and road debris. Specific areas, like trailer wheel locations, are more prone to degradation. Once water-based paint breaks down, the wood absorbs moisture, causing warping, swelling and deterioration of glue bonds. What's worse: once the undercoating has been breached, water can migrate into the trailer itself, resulting in severe cargo damage.

PROLAM takes on the challenges of water-based paint

undercoatPROLAM's P•u•R solution provides never-before-seen protection for wood trailer floors. The hot-melt polyurethane reactive P•u•R undercoating is used on the underside of laminated trailer floors and eliminates the degradation issues associated with traditional water-based paint undercoatings.

PROLAM's P•u•R undercoating provides protective features for wood trailer floors that standard water-based paint undercoatings cannot match, including:

  • .010" P•u•R thickness compared to a .0035" water-based undercoating.
  • P•u•R viscosity forms a perfect adhesion to laminated hardwood, creating a solid bond.
  • P•u•R "bridges" wood defects, knots as well as critical areas, such as butt-end joints, providing a single uniform barrier against moisture penetration from the underside of the trailer floor.
  • In sandblast tests, P·u·R was 11-times more abrasion-resistant than water-based undercoatings.

A cut above traditional water-based undecoatings

Weather and elements weaken water-based paint coatings under trailer floors, leading to warping, uneven swelling stresses, and degradation of glue lines. Once the coating has been breached, water can migrate into the trailer itself, resulting in cargo damage.


Tensile tests measure the force required to break a sample material and the extent, measured in percentage, to which the specimen stretches or elongates to that breaking point.

Water-based undercoating elongation: 5%

P•u•R elongation: 600%

Determines resistance to abrasion, or the ability of a material to withstand rubbing scrapping, or erosion; Measured by the number of cycles needed to create weight loss.

Water-based undercoating abrasion test: 20 cycles

P•u•R abrasion test: 225 cycles

Measures adhesion of a undercoating material to metallic samples by applying and removing pressure-sensitive tape over cuts made in the undercoating. Measured on a scale of 0 - 5, with 5 representing the least amount of lifting.

Water-based adhesion: Class 4

P•u•R adhesion: Class 5

Measures amount of water absorbed after sample material is exposed to moisture;
Measured in grams per 100-square inches.

Water-based absorption: 29.9 grams/100 sq. inch.

P•u•R absorption: 3.4 grams/100 sq. inch.

Check out the results of an 8-year test with PuR