Hi

Hope i'm in the right section!

I'm new to this forum, registered because I have found lots of useful information and tips on this site.

I'm a DIY tiler, only tiled 2 bathrooms before.
I am looking to take on what I think is quite an ambitious project - I might regret it - and need some advice.

I want to box in an oval bath, incorporate a step, and tile it all.

I will build a wooden frame, and my questions relate to the surface I tile onto.
From this forum, I think I need to tile onto hardie backer 500.

Can I put this board straight onto the frame for the horizontal area round the bath, and the vertical side of the bath and the step - or do I need to put ply underneath it for strength?
I intend to put marine ply under the board on the horizontal surface of the step.

Will I be able to cut this board into an oval shape for round the bath?

Any advice welcome! and thanks in advance!

Yess you can glue and screw to frame. The 12.5mm hardie is very strong but depends on the size and framework of the step as to whether it will be strong enough (my guess is with solid framework it will be fine - I would suggest using NoMorePly 25mm screws and their glue.
Cutting the oval out of the Hardie is possible but I wouldn't attempt it without the right powertool - If I were doing this job I would use my Rotozip with an X-bit Diamond Floor Tile Bit.
Good luck with the project

Large Tile nippers cut cement board well too, so thats another option (cheaper too but will take a while).
Suppose you could use ply for the cut out and use a jigsaw.

Wot about Marmox curvable boards Never used them myself.

Marmox Curved Insulation Board - Marmox UK Ltd

Thanks for your help.
I've added a picture of something similar to what I'm trying to achieve.
Except - My bath is oval not hexagonal, and i've not got the back corner cut off mine goes into the corner.



Thanks again