There is no other reason for adding it.
Should a shower door frame be sealed with silicone underneath.
Broadly speaking the shower tray should be level and fully sealed to the tiles before the enclosure is installed the sides of shower enclosure should be vertically plumb and fixed securely to tiled walls.
Invest in a shower door side seal to solve the leakage issue from the sides.
Solutions for fixing the leaks on either side of the frameless shower door.
Ds9382 shower door sweep.
Caulk made of pure silicone or siliconized latex acrylic i e latex or acrylic caulk with added silicone adheres well to common shower and tub materials including porcelain ceramic stone.
Either way it is the inside edges on the verticles.
I m sorry to hear about the mix up with your shower enclosure.
Silicone sealant is added to the joints between the glass and tile the perimeter to prevent leaking.
If i understand your question correctly we assume you are talking about a glass shower set like a neo angle shower or a glass door set on a tub.
Silicone sealant should be applied vertically on the inside and outside where the shower enclosure fixes to the tiled walls and importantly on the outside only.
For a shower door or enclosure to work correctly it must be installed in accordance with the manufacturer s instructions.
Grout isn t suitable for sealing around your bathtub or shower tray as it s not flexible and will crack as soon as any weight is placed on the tub or tray.
I always try to talk people out of using silicone on frameless enclosures of this type.
Make sure you have silicone sealant and not normal grout.