When the Vieser waterproofing membrane flange is used together with a Vieser floor drain, is it necessary to protect the visible part between the frame and the drain’s clamping ring with mortar?

If a Vieser grating with a plastic frame or an adjustable stainless steel frame is installed together with the floor tiling, it is not necessary. The stainless steel frame must be installed so that the membrane flange is covered.