I had a leak coming under the front rail of a quadrant shower enclosure so have pulled it all out to reseal, but as always it throws up questions 
The sealant joining tray to tiles was mouldy so I've removed that too, but there are a few bits of grout missing - quite thin gaps say 2-3mm and 2-4cm in length are missing
Should these be filled with grout or squeezed full of silicone before putting the new bead in?
Secondly, the oft-asked question about sealing on the outside only This is the bottom rail, upside down so you can see the surface that will be in contact with the tray
This is solid all the way around - no drainage holes in it. This was previously sealed just on the outside edge but it was clear that water has sat underneath it on the inside edge as the surface has deposits/staining on it. I understand why they say don't seal the inside, so any water can drain into the tray, but looking at this design I don't see a problem sealing this rail on the inside, am I wrong?
The sealant joining tray to tiles was mouldy so I've removed that too, but there are a few bits of grout missing - quite thin gaps say 2-3mm and 2-4cm in length are missing
Should these be filled with grout or squeezed full of silicone before putting the new bead in?
Secondly, the oft-asked question about sealing on the outside only
This is the bottom rail, upside down so you can see the surface that will be in contact with the trayThis is solid all the way around - no drainage holes in it. This was previously sealed just on the outside edge but it was clear that water has sat underneath it on the inside edge as the surface has deposits/staining on it. I understand why they say don't seal the inside, so any water can drain into the tray, but looking at this design I don't see a problem sealing this rail on the inside, am I wrong?
