Schluter® PRIMER-U Universal Primer cleaner It offers the unique flexibility

It offers the unique flexibility of installing floor coverings after a short flash time or once the adhesive exhibits pressure-sensitive characteristics

Not only does it cost significantly less than porcelain

Liquid-applied membranes (like RedGard) require multiple coats

Trying to fold wet

Schluter® PRIMER-U Universal Primer cleaner It offers the unique flexibilityPRIMER U is Schluter's universal primer a ready to use, water based formula that improves the bond of thin set mortar to substrates that resist adhesion. Where PRIMER PS is specifically for peel and stick membranes, PRIMER U works with standard mortar set Schluter products (DITRA, KERDI, KERDI BOARD) and general tile installation. Use it when your substrate is too smooth, too dense, or has residual contamination that would compromise mortar adhesion.