When I bought my house it had newly (poorly) fitted bathroom suite. On the back edge of the bath where the taps are there was a L shaped plastic strip that fit behind the tiles to stop the water running down the back of the bath when the shower (in the bath) was being used. Soon this lifted up and let water underneath, after lots of attempts to block this up with silicone i eventually pulled it out and fitted a strip that goes in front of the tiles.

This worked fine for a couple of weeks but the rubber edge the contacts the bath soon curled up and started letting water in. I ended up cutting this off and filling the bottom with silicone, this has made it better but I cannot stop the last bit of water getting through.

I'm reluctant to take the tiles off and start again with another strip because the last one didn't work so well. So are there any other ways of sealing the edge before I start pulling the whole thing to pieces and starting again.

I've the same problem! The edge sort of dries and raises up. I've just gunged it up neatly with non mould silicone sealant.

Are you filling the bath with water before you apply the sealant? If you're not, the the bath will move when you get in and out, and stretch the sealant, breaking the seal....

Fill the bath with water before applying the silicone sealant then it should not have to stretch when you subsequently use the bath.

I had problems with the Bath flexing and pulling the silicon seal, made a rough wood support frame to wedge the bath rim, then cleaned and resealed the bath edge.
Worked for the last 4 years.

Have been filling up the bath with water when I applied the silicon, might have a go at knocking up a frame though as i think there is a bit of movement when you step in and out that might be breaking the seal. Not so much pulling the bath down but side to side.

There are also different qualities of silicone, dont get the cheap ones! You need a good one in a bathroom, especially round the bath.

To get it neat, you can put masking tape onto the bath and tiles. The better silicones usually take longer to dry, often 24 hours with no water at all. Also, make sure the crack is dry - hair dryer if necessary.

Every time I've used masking tape, it just leaves a crap looking ridge/line when I remove the tape. Probably just bad technique - but I dont care cos when I found one of these I never looked back! Awesome...

http://www.toolbox.co.uk/unibond-uni1036578-sealant-1979-99091

Take the front panel off and fit a block of wood under the centre of the bath. Most cheap suites move considerably and
will always leak. Best way is to remove bath and start again. Do not use sealing strips as they are hard to replace whe faulty. Best stick to silicone sealant . Any quick fix will only be temporary sorry.

Use some expanding foam around the edge of the bath,this will make you bath solid then apply the silicon( Go easy on the foam as the cheap stuff can expand to much small tip once you have done the foam spray it with water and the foam will expand quickly)

From another forum


Removing/applying silicone to joint of bath/shower and tiles
Removing silicone
Carefully use a sharp chisel and slide it along the bath/shower surface, then the tile surface at a shallow angle and the silicone will come off easy.

Applying silicone
Here's a fool-proof method that gives a perfect finish.
Clean and dry the area - use meths. Mask off a nice straight line (top and bottom of the joint) using either masking tape or electrical tape (electrical tape sticks to tile better than masking tape).
Fill the bath with cold water.
Apply a bead of sealant to the joint then run along the bead with your finger in one continuous movement. You now have the perfect amount of silicone for the seal.
Remove the tape as soon as you've done this. When removing the tape, you'll have pulled the edge of the seal a little, so you need to go over the whole seal again with a wet finger.
You should now have a perfect seal around your bath/shower.
Drain the water from the bath after around 4 hours when the sealant has gone off.

Most folks on here recommend Dow Corning 785
Original Link

As already said, only use the silicone sealant. there are cheap and nasty acrylic ones out there but they just dry out and crack, total rubbish!

I have a similar issue with our bath and might end up putting a brace under the main body of the bath to give it more support. Just remember not to make it too small or the pressure might be too much on a small surface area of the bath and crack it.