Hardibacker Board - should I use it on the walls?

[lawrenso]

Hi All,

I have picked up some 6mm Hardibacker today from Topps but they had no screws in. This has given me time to pause and contemplate.

I was going to use it on the wall adjacent to the bath. The bath goes across the full width of the end of the room. The tap end is on Wet Plastered on Block and the side and other end is on a stud wall (12mm plasterboard, skimmed). We are installing a proper mixer shower above the bath and I was going to use the backer board on the long side of the bath (there is a step out from the wall as well to act as a shelf about 10cm above the bath edge).

When I ripped out the old tiles I found that a lot of water had been getting through onto the front corner of this shelf and I have had to replace some wood because it was a bit rotted and remove the plasterboard. It was because of this I thought of using a backer board to give some moisture protection.

However, looking at BAL's site on the tanking I am wondering if I could get away with just building the shelf again with the backer board and taping around the shelf etc with something like the dunlop tanking kit, then tiling onto the plasterboard alone. Would this be enough. The shower will be used primarilly for washing the childrens hair with only very occaisional use as a shower as our en-suite one is excellent. The shelf will have to withstand copious amounts of water being poured over it though (kids )

The board I have got will not go to waste as I will be using board on the floor above ply.

Thanks in advance for any comments or advice

Steve

[Dave]

12mm hardi for walls......

[lawrenso]

12mm hardi for walls......

Cheers Dave, I was going to fix it straight onto the plasterboard through into the 4*2 studs hence only using the 6mm. If I was removing the plasterboard I would use the 12mm.

Question is, would I get away without using it for the usage described in my earlier post?

When I do the en-suite shower which is used everyday I will be removing the plasterboard there and using 12mm on the stud wall as this is the shower used everyday.

Cheers

Steve

[Dave]

As long as you tape the joints then yes...no probs.....

[lawrenso]

As long as you tape the joints then yes...no probs.....

Thanks for that Dave. I am going to order the Dunlop Tanking kit and I am going to tank the tap end and the side of the shower, as well as tape all edges of the shelf and all corners. The shelf is going to be rebuilt using the backer board.

What advice would you give in dealing with the lip where the tiles come from the horizontal down to the vertical. The previous tiling had a plastic corner trim on it but this was where the weakness was. Any tips of the trade to deal with this would be appreciated.

Also, where can I buy the tape on its own as I will need about 2 mtrs more than the 5 that comes in the kit?

Cheers

Steve

[pt44]

If I was waterproofing - I would use Wedi board and seal the joints with the Wedi waterproof tape, which you apply with fully flexible waterproof tile adhesive. Wedi board is really easy to work with and this would provide you with a fully waterproofed backer.

As for the shelf edge, if its fully waterproof underneath, its not that important what's above I would have thought. However, to be sure, I would always overlap the top tile to form a little overhang over the vertical tile. But maybe that's because I hate corner beads, so have never used them. Hopefully this should provide a small drip ledge, like a window ledge.

I've used hardi before - but never for tanking. Perhaps it can be used for that - but I've no experience of it. Whereas Wedi is built for that very purpose.

Paul