Can this be installed over a shower insert? Not sure the material of the insert.

Thank you for your interest in our Palisade tiles! The panels can be glued to smooth surfaces such as plaster, plasterboard or even to existing tiles. Other substrates in a dry environment that will work are drywall, plywood and OSB. In a wet environment, such as a tub or shower area, existing ceramic tile walls can be covered with no additional preparation required. Otherwise, installation over a waterproof substrate is required, such as Cement Board®, Schluter Kerdi Board®, GP Densheild®, Johns Manville Go Board®, Hardiebacker®, WPBK Triton®, Fiberock® and equivalent products. Always follow manufacturer’s installation instructions to create a waterproof enclosure.