However
Acrylic and fibreglass scratch easily and can yellow over time
Caulk at seams and edges must be maintained and replaced periodically
If a panel cracks or stains badly, the entire panel or unit usually needs to be replaced
Grout lines require cleaning and occasional re - sealing
Individual cracked or damaged tiles can be replaced without affecting the rest of the shower
Properly grouted and sealed tiles are very hygienic
High - quality porcelain tiles are extremely scratch - resistant and do not yellow
