Fixing Hardibacker direct to chipboard?

[CCTiling]

Hi all,
Just tried to pm hardi rep on here but it said his mailbox is full (popular guy!!) so thought I would ask the rest of the knowledgable bunch.

I have a job next week (weather permitting!) laying 20mm thick marble tiles. They're to be lay onto chipboard flooring so I wanted to lay hardibacker to give max strength for weight of tile.

2 questions :

-What thickness would you recommend, 6 or 12mm?

-Would I use spf or 2 part flexi addy as well as screws to fix the boards?

Thanks Ross

 

[DHTiling]

When you say chipboard...Is it onto joists and if so what thickness.?

 

[CCTiling]

When you say chipboard...Is it onto joists and if so what thickness.?

Hi Dave...yeah it is on joists and is 18mm thick

 

[DHTiling]

Ok...There might be deflection issues..have you looked at this..?

 

[CCTiling]

Ok...There might be deflection issues..have you looked at this..?

No I haven't checked this yet. The chipboard is covered over with ceramic tiles and carpet at the moment

 

[DHTiling]

If the deflection is ok..then 6mm hardi with a good quality s1 adhesive is ok..but the deflection must be minimal.

 

[CCTiling]

If the deflection is ok..then 6mm hardi with a good quality s1 adhesive is ok..but the deflection must be minimal.

Ok thanks Dave. I will check the deflection. I was thinking I would need to fix with a 2 part adhesive the same as fixing tiles to chipboard.

 

[DHTiling]

That will be the option if the floor is a bit bouncy..

 

[CCTiling]

That will be the option if the floor is a bit bouncy..

What make adhesive would you buy if the deflection is ok?

 

[White Room]

On top of the hardie I use a single part flexible

 

[DHTiling]

What make adhesive would you buy if the deflection is ok?

Used to be BAL... but since i tried Mapei then it would be Keraquick..and mapei is more cost effective for me..