What to use as packing under flat bottom free standing bath

[Lower]

I'm installing a modern free standing bath which has a flat base.

It's essentially a double skinned bath with expanding foam in between the inner 'bath' skin and the outer visible skin. Either the bath is slightly warped or more likely the floor isn't dead flat but there is a gap under the bath that starts roughly in the middle and increases to about 5mm along the front edge.

Obviously i need to pack this with something, but because of the varying height of the gap i'm not sure what to use. I could whack in a load of silicon as i'll be siliconing the front edge to the floor anyway but i'm concerned that the silicon will squash down to much when the bath is full of water and pull away from the seal at the top edge.

Any suggestions as to what i should use?

 

[kevplumb]

fill the bath before you seal it

you could also try bedding it on an adhesive base

 

[Lower]

I will fill the bath before sealing round the top, but i need to get the packing in before i fill it as otherwise i suspect it will just deflect to the shape of the floor and the bath itself will pull out of square.

I've not used gripfill before. Is it a 'no nails' type adhesive for the trade? Does it set fairly rigidly?

 

[GarethSullivan]

fill the bath before you seal it

you could also try bedding it on an adhesive base [

filling the bath before sealing it won't work in this case because you need to get the silicone underneath it. You'd be abit buggered if you need to put more underneath it, unless you emptied the bath then refilled it again after adding more sealant.

 

[kevplumb]

I've not used gripfill before. Is it a 'no nails' type adhesive for the trade? Does it set fairly rigidly?

yup

filling the bath before sealing it won't work in this case because you need to get the silicone underneath it. You'd be abit b*****r if you need to put more underneath it, unless you emptied the bath then refilled it again after adding more sealant.

you bed the bath BEFORE you fill it

then you seal it

 

[Lower]

Which type of gripfill should i use? with or without solvent?

I'd be bonding the plastic bath to honed travertine tiles.

 

[kevplumb]

personally i'd go without