Tiling round bath

[Avagojo]

Can anyone please advise me whether I should tile the wall and put the new bath up to it, and then use sealant, or tile on to the lip of the bath so that the first tile is on the edge of the bath and then the sealant?
Hope that makes sense.

 

[gcol]

Tile onto the bath. Fill the bath with water then seal the edges with silicone sanitary sealant. Use electrical insulation tape to mask the edges before you apply the sealant for a clean seal. (electrical insulation tape sticks better than masking tape)
Empty the bath after a few hours.

 

[Avagojo]

Thanks gcol for your advice.

 

[Nestor_Kelebay]

What's commonly done here in North America is as follows:

1. staple a polyethylene (which I think you call "polythene") plastic vapour barrier to the wall studs and caulk the bottom edge of it to the 1 inch lip of the bathtub that sticks up. That way, any water leakage can't get into the wall.

2. fasten the tile backer to the wall studs over the plastic vapour barrier. The bottom edge of the tile backer should stop just a little (1/8 to 1/4 inch above that 1 inch lip around the bathtub. The tile backer is much thicker than the 1 inch tall tub lip, so the front of the tile backer overhangs the tub lip.

3. tile the walls. The bottom row of tiles will hang down unsupported in front of that 1 inch lip around the bathtub and extend down to the top surface of the tub.

4. grout the tiles and then caulk the joint between the tiles and the tub

I'm wondering about filling the tub with water prior to caulking.

My understanding of the purpose of this is to caulk the joint when it's spread as far apart as it's likely to ever be so that the silicon is not in tension when the tub is full of water.

But, since silicone caulk is very elastic and sticks tenaciously to both glazed wall tiles and the enameled surface of a bath tub, any tension in that silicone caulk is of no real concern.

I'm wondering if it wouldn't be safer to caulk the tub when it's still dry and empty to avoid adhesion problems. If you accidentally splashed water onto that joint during the caulking job, then he silicon wouldn't stick to the wet area, and you'd be rushing to dry that spot well before continuing the job. And, that situation isn't conducive to an attractive caulking job.

If it were me, I'd caulk the tub with silicone, wait a day, then fill it with water to have a well deserved long leisurely bath, but I'm open minded to having someone changing my opinion on the matter with good reasons for caulking it when it's full of water or good reasons not to caulk it when it's empty.

 

[gcol]

Nestor,
I can't speak for what happens in america/canada and I haven't seen any baths over here with an upturned lip.
Does it not make sense to seal the bath in a state where any weight in the bath would be in the middle of it's working range? If you fill the bath (or almost fill it) then the weight in the bath is about half what it's maximum user weight would be. Add a body and it'll be heavier.
When the sealant has gone off and the bath is empty then the sealant will push back up against the tiles. The danger is that if you don't apply the sealant when the bath is full then you run the risk of pulling the set sealant from the lower run of tiles when the bath is at it's fullest. Depending on how well the sealant has been applied will depend on whether the sealant can withstand that pulling force.
Nine times out of ten it'll be fine to apply sealant to an empty bath but for what's involved I always fill the bath - it only takes 5 mins.

 

[Nestor_Kelebay]

All of the enameled steel bathtubs over here have a 1 inch high lip that runs along the front, side and back of the tub. You push the tub into place so that, ideally, this lip is directly in front of the wood studs of the walls around the tub.

I've seen the recommendation to fill the tub with water before caulking with silicone on a large number of DIY forums here in North America as well. I always presumed that the reason for this advice was because people were having trouble getting the new silicon to stick when REPLACING mildewed silicon caulk around a tub. In this case, however, the real problem is that nothing sticks well to silicon caulk, not even silicon caulk. The trick to getting new silicon caulk to stick well is to remove the old silicon caulk completely. Once you do that, silicon caulk will stick to glazed wall tiles and bathtub enamel like chewing gum to the underside of a church pew!

 

[gcol]

The trick to getting new silicon caulk to stick well is to remove the old silicon caulk completely. Once you do that, silicon caulk will stick to glazed wall tiles and bathtub enamel like chewing gum to the underside of a church pew!

It certainly will. And I suppose you use a stanley knife blade held in a pair of locking pliers to remove it do you?

 

[Nestor_Kelebay]

Yep, that scraping tool works partucularily well for lots of different tasks.

 

[lilac]

but why not tile the whole wall - then push bath up to it ? does it not stick ?

 

[Nestor_Kelebay]

If you have a free standing bathtub, then I don't see any reason not to tile the whole wall and push the bathtub up to it.

It's just that I was wrongly assuming that the poster had the same kind of bathtubs we have over here, which are meant to be surrounded on 3 sides by walls.

Our kind of bathtubs have a steel lip on the three sides where the walls would normally be that sticks up about an inch. Also, our bathtubs have a skirt on one side that supports them, and the other side is meant to be supported by a 2X4 nailed to the wall.

So, with our kind of tubs, you couldn't really tile the whole wall first and push the bathtub up to it. With our kind of tubs it's better to push the bathtub up to the bare studs walls, and then install polythene and tilebacker board only above the bathtub and tile only the wall above the bathtub.

Sorry for the confusion on my part.