Max gap to fill with silicone

22 Dec 2005
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United Kingdom
I've just finished tiling my bathroom and need to seal the tiles up to the bath but have a quite sizeable gap to fill.

I left a 5mm gap between the tiles and the bath but the bath runs out a bit along its length as does the floor (its a freestanding bath) so the gap gets as large as 9mm at the end.

Is 9mm to large to fill with silicone? If so, any suggestions as to what i should use?

My other option option i've considered is to fill the excess gap with grout or gripfill and then silicone over the top so that the silicone has more support.

Thanks in advance.
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put a batton on the wall to support it You say its a free standing bath, so jack it up if the floor is out four mill and the gap is even, tiles should be level and bath top should be level
I don't have a pic but may have tomorrow. The bath is tight to the wall with and i've tiled down to the top of the bath. But because my tiles are level and the bath and floor run out slightly the gap gradually grows along the length of the bath by about 4mm. The floor probably runs out by 2mm or so and the top of the bath by another 2mm or so, hence the gap.

I could quite easily fill the gap between the tiles and the bath with grout, and then silicone over the top to give the seal which would mean a much smaller amount of silicone. Thinking about it, i ought to do that anyway as the tile to wall gap is about 10mm or more deep so it would be an exceptionally large silicone bead!

Bath can't be jacked up as it sits flush to the floor (ie flat bottom not feet) and i've already bedded it into a gripfill bed so its not going to move easily anytime soon!
Quadrant tiles aren't really going to work as tiles are filled and honed travertine.
After a bit of experimenting with grout last night, my plan is to fill the gap with grout and then silicone over the top.

Photos as promised

Left hand end where gap is fine


Middle where gap is slightly larger but ok


Right hand end where bath falls away towards the end


Where i've filled the gap with grout as a trial before i silicone


Any problems with doing what i'm doing?

Yes i will fill the bath before i silicone.
So what's not level, your bath or your tiling?
If it were me I'd try and jack the bath up a mm or two to make it a bit better. Personally I would pump silicone between the bath and wall on all sides anyway to stabilise it and stop any moisture from penetrating below in case the grout/silicone line fails.
This might be of interest
The floor under the bath has a slight run and the top edge of the bath itself has a slight fall to it. The tiling is dead level.

Basically, the bath is a free standing, flat bottomed design (ie no feet so it can't be jacked) that is not designed to sit against a wall in the way that we've installed it.

That seal would do the job but unfortunately looks ugly.

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