Bath shower screen rubber seal

[Merlin5]

I've had a new shower screen installed over my bath. The rubber seal is inadequate as the flap at the bottom needs to be longer to make a proper seal, I have to physically adjust it to make sure it's bending flat against the lip of the bath. I can change that for another one, but the main problem is a 2 to 3mm gap where I've marked in yellow in my pictures, and I assume the same thing would occur with a replacement seal? There's a gap between the yellow arrows where the seal butts up to the round chrome post. What can I do to fix it? My builder said he would put more mastic there, but I can't really see if that would solve it. Water leaks on to the floor there, so I've been pulling the screen at nearly 45 degrees towards me to stop that happening when showering.







Should I try cutting a few mm section of the plastic part above the rubber like this guy demonstrates from 5:45 of the video?
http://www.youtube.com/watch?v=hR8cycIh2NQ

 

[duffin]

yes you could try that, but first trim off the silicone thatgoes past the line of the screen at the base.the seal should fold inwards so the surplus sealant is stopping it.