Adhesives for hardie backer board?????

[cityone]

Hi lads, this is following on from my post the other night where i have decided to use hardie cement boards instead of plywood due to the poor quality of ply now available. Anyway, i would like to use the 6mm board (because of raising height issues) for floor overlays but BAL (my prefered choice) only recommend single part fastflex which is 3 times the price of my usual floor adhesive, (bal spf) if i used the 12mm board i would have no problem with spf, so for 6mm backer board what floor adhesive do you recommend???? also, can i get away with just screwing the backer board to the substate or do i have to use adhesive as well as screws??? once again thanks in advance for any feed back!!!!

 

[Ian]

Always stick as well as screw ( that sounds rude!), SPF is perfect for the job.


Sent via Tapatalk for iPhone

 

[cityone]

Cheers Bri, when you say stick as well as screw i gather you mean spf under the board before screwing?? so BAL spf is ok for floor tiles on 6mm backer board????

 

[Ian]

Yes mate, screw it down while the adhesive is still wet, use a 6mm trowel and leave 2mm expansion gaps between boards, hardie also make tape for the joints, looks a bit like scrim tape.


Sent via Tapatalk for iPhone

 

[kent tiler]

im ment to be pricing up my mums new bath room floor soon what do you mean the ply now days is crap mate??
soo if i was too tile over floor boards how do i go about it then mate using backer boards


i used to too use i think it was 18mm ply stuck down with pink grip and screwed 400mm centers
how do you use tile backers board do you use the ditra matting over it or over ply ????????

 

[AliGage]

I use BAL. SPF with a 6mm trowel is generally what i use, certainly if it's going onto new ply.

Hardies tap is pricey. Normal plasterers skrim tape is the same thing and a third of the price.

 

[kent tiler]

im lost whats going over ply

 

[mattle40]

I thought the same lol surely new ply doesn't need backer board....

 

[Ian]

Sometimes the chipboard is replaced with ply before the hardie goes down, onto the joists.

 

[kent tiler]

can you use ditra matting over floor boards or just tile backer boards then tile

or tile backer board ditra matting then tile

 

[Thespanishtiler]

Hardies tap is pricey. Normal plasterers skrim tape is the same thing and a third of the price.[/QUOTE]

Its not the same, hardie tape is alkaline free. Scrim is not.

 

[mattle40]

how do you use tile backers board do you use the ditra matting over it or over ply ????????

Hardie just needs SPF 6mm notch bed onto your floorboards, screwed at 300 centres while wet
Then tape the joints and youre good to go pal

 

[swanman]

Look this is geting silly lets put this into simple terms

All you need to do is put down 6mm hardi board glued down with fast flex and screwed down Then if you want to you can tape it but personally i dont bother

Good LUCK

 

[mattle40]

can you use ditra matting over floor boards

You can yes but you would need to use highly polymer modified addy like bal fast flex to fix the ditra (4mm notch) and the tiles solid bed

 

[AliGage]

Hardies tap is pricey. Normal plasterers skrim tape is the same thing and a third of the price.

Its not the same, hardie tape is alkaline free. Scrim is not.[/QUOTE]

Hmmm, Heinz or Aldi's own brand?

Effectively it does the same job.

 

[macten]

Just use any cheap bagged adhesive, it is there purely to fill the voids, it's the screws that hold the board to the substrate.

 

[mattle40]

The alkaline resistant scrim is specified because cement can weaken plasterers scrim which effectively makes it useless

 

[tobins tiling]

Its not the same, hardie tape is alkaline free. Scrim is not.

Hmmm, Heinz or Aldi's own brand?

Effectively it does the same job.[/QUOTE]
Heinz please allister lol

 

[kent tiler]

whats cheaper and faster too lay ditra matting or backer boards over floor boards

 

[White Room]

You can yes but you would need to use highly polymer modified addy like bal fast flex to fix the ditra (4mm notch) and the tiles solid bed

I have never used Fastflex for ditra, a spf has allways been adequate...

 

[Olz]

Same here, I make sure the floorboards are screwed down and movement free, overlay hardi usually with webber SPF with a 6mm trowel and screw through with 25mm turbo gold screws which are self tapping and go in nice and easily. The screws are put in whilst the addy is wet, easy with the hardi as it has pre marked screw down positions.

The addy is there to fill the voids under the boards, its the screws that hold it down.

 

[mattle40]

I have never used Fastflex for ditra, a spf has allways been adequate...

My knowledge of it was that you would decide what adhesive to use by disregarding the use of ditra it's self

I.e in the case of tiling on floor boards you would use fast flex without ditra so you still use it with it, same goes for ply, you would use SPF without ditra so use SPF with it..

I may well be wrong and sorry if I have miss informed anyone il check tomorrow

 

[The Legend; Phil Hobson RIP]

As Oli for me, But I edge my bets by using Mapei Keraquick with latex plus. Don't agree with using decoupling membranes over T&G floors, these membranes do nothing to overcome deflection, sub floor must be solid, cement boards when laid correctly will help, whereas Ditra or the like only cope with lateral movement/crack isolation etc. imho.

 

[cityone]

Thanks oli, (and all the other replies) so after fixing my 6mm backer board to the sustrate, (floorboards, blockboard etc) i can lay my tiles onto 6mm backer using BAL spf, the reason i ask is that bal techs say that if it,s under 10mm thick spf is not recomended???

 

[DHTiling]

Thanks oli, (and all the other replies) so after fixing my 6mm backer board to the sustrate, (floorboards, blockboard etc) i can lay my tiles onto 6mm backer using BAL spf, the reason i ask is that bal techs say that if it,s under 10mm thick spf is not recomended???

Then use another brand. .