MAPEI recently introduced MAPEI HM Primer™, a ready-to-use, low-VOC, water-based, quick-drying primer. Designed to be used with MAPEI’s peel-and-stick sheet membranes, MAPEI HM Primer reportedly promotes maximum adhesion to high-moisture substrates. 

“The HM stands for ‘High Moisture.’ It is formulated to enhance the bond between Mapeguard® 2 and Mapesonic™ 2 and a variety of substrates, including nonporous concrete and metal,” said Sonya Moste, product manager for Sound-Control Membranes and Crack Isolation.

MAPEI HM Primer is low in odor and can be applied with a roller or brush. Designed for interior or exterior applications, the primer can be applied to substrate and ambient temperatures as low as 40°F (4°C). It can also be applied to substrates with a moisture content up to 15 lbs per 1,000 sq ft (6.80 kg per 92.9 m2) per 24 hrs using a calcium chloride test kit (ASTM 1869). However, it is not considered a moisture-control product. 

“MAPEI HM Primer is a great high-tack primer, and it is perfect for high-moisture slabs in high-humidity climates,” Moste said. “When used with our sound-control and crack-isolation membranes, it’s part of a system solution that is great for slab-on-grade concrete, as well as young concrete for new construction.” 

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