Tile Backer Board Questions

[Salar]

Hi all, as you can see I'm new to the forum but a competent DIYer so I hope these are sensible questions. I am removing a bath with a tiled surround and replacing with a walk-in shower from Merlyn. I am building a stud wall to be one wall of the shower. I will be using HardiBacker 500 for the stud wall, but the existing wall (also stud) has a plasterboard surface. Two questions:
1. Would you take off the plasterboard and put 12mm tile backer board up instead, or would you fix 6mm tile back over the existing plasterboard? Tiles are standard, not heavy.
2. I have not fixed tile backer board before - what would you do to prevent movemement at the backer board joints when fitted on a stud wall? Or is this not necesary? The house is a barn conversion so there is more movement in the structure than a normal house, but not a lot.
Thanks in advance for any advice.

[Dave]

Hello and welcome.. Have not thought about just tanking that wall instead..?

[david campbell]

to the forum
as above tanking would be the cheapest and quickest option but if you are using the boards then you will need to add extra noggins to minimilise movement

[Salar]

Hello and welcome.. Have not thought about just tanking that wall instead..?

Thanks for the speedy replies. The wall is a bit mangled, there are a few holes in the plaster and there have been 2 sets of tiles on it and then taken off, so the surface is horrible. I had hoped to cover with a smooth surface to tile over. Is there a better way than backing board over plasterboard for that?

[Dave]

You could just remove the plasterboard if it is a stud wall..?

Also schluter have new board out called Kerdi board and that can be dot and dabbed into situ.

[Tecnik2000]

Hi salar & welcome, seems to me you have answered your own question. Looks like the best thing to do is a strip off,no future in trying to get flat on a gammy background. You can stiffen the wall then as needs be & use the thicker backer.. IMO

[Salar]

OK, wall off and 12mm Hardibacker....Would you believe this all started with wifey thinking we could just put a splash screen on the side of the bath? £3,000 later we have a megaflow system in to give us shower pressure in two bathrooms, and a demolished bathroom. Just a bit more demolishing to do then we can start the rebuild. Trouble is she STILL hasn't decided on the shower fitting, the hall is piled with materials but I can't start until I know where the pipes are going. Doh!

[Dave]

That's Women for you..

[timeless john]

Whats all this 'she' business - who makes the decisions down there? - and why didn't you just agree to a splash panel and a boys room conversion with snooker table and bar!

[Diamond Pool Finishers]

hi to the forum

[Salar]

That's Women for you..

Not a problem actually. I'll be going fishing until she decides on the shower.