The Dec Scanner detects and evaluates the moisture conditions within roofing and waterproofing systems by non-destructively measuring the electrical impedance. The instrument operates on the principle that the electrical impedance of a material varies in proportion to its moisture content.

The Dec Scanner can read up to 6” (150mm) through roofing systems and insulation.

The Dec Scanner can be used on a roof system while the aggregate is left in place provided the aggregate is of uniform thickness and is no larger than coarse gravel (approx. .63-1.26 in). The aggregate should be dry to allow signal penetration to the roof system below.

The Dec Scanner gives most meaningful results when used on a dry surface. This allows the signal penetration to read as deeply as required through the surface into the roof system.

The Tramex Dec Scanner and RWS Roof and Wall Scanner are not suitable for use on any roofing with electrically conductive or metal-faced membranes. Metal and other electrically conductive surface coverings and near-surface embedded metallic components are not suitable for surveying with these instruments because of the electrical conductivity of these materials. Most types of black EPDM produce false positive readings when tested with this method due to the material’s high dielectric constant. The degree to which these false positives need to be factored out will affect the depth of signal penetration. Aluminum foil on top-faced insulation or waterproofing membranes give false positive readings, however liquid-applied aluminum pigmented emulsified asphalt based coatings do not normally have a significant effect on the readings.