Should Hardiebacker boards be used or not?

[jason67]

Hi All

I’ve just had a loft conversion with one of the rooms being a bathroom. The floor is P5 grade (the green tinted moisture resistant stuff) 22mm chipboard and has been layed absolutely flat. The walls are skimmed plasterboard.

I would like both floor and walls tiled but it's the floor I'm concerned about. I’m using Wickes ceramic Tiles 33x33cm (8mm thick) for the floor.

I’ve bought Hardibacker boards to lay on the floor, but havn’t fitted them yet as I was hoping my tiler would quote for this job along with the tiling. Would it be reasonable to assume that laying Hardibacker boards is a job that a tiler would undertake?

I had an experienced tiler come to give me a quote yesterday but was surprised to hear him say that I don’t need Hardibacker boards. He said that he uses a special rubber based adhesive to fix the tiles directly to the P5 chipboard flooring. I’m a little concerned that this is not the correct fixing method and that Hardibacker boards should be used.

Could anyone give me a little advice on this?

 

[Ian]

Should Hardibacker boards be used or not?

100% use the hardie boards. To suggest tiling straight to the chipboard is ridiculous. And yes, fitting the hardies is all in a tilers prep work.

 

[JamesHardie]

HardieBacker is a Cement based board that provides a suitable surface to tile on to. Unlike wood, it does not expand and contract with exposure to water. Attached is a copy of the HardieBacker installation instructions.

If you are looking for an additional document to source take a look at this NHBC Standards – Section 8, Part 3, Para D4

TILES ON WOOD-BASED SUBSTRATE
The floor should be designed to take the additional loads of tiles and any other materials (e.g. overlays). Tiles should be suitable for laying over a timber base.
The floor decking should be: chipboard floor decking overlaid with minimum 10mm plywood suitable for exterior conditions and fixed as above, or proprietary separating/de-coupling layers, tile backer boards or tile bedding reinforcement sheets used in accordance with the manufacturer's recommendations.

I hope this helps

 

[Gazzer]

Can someone explain this,

"Apply a gap filling bed of non-flexible tile adhesive to the subfloor using a 6mm notched trowel."

 

[Peter]

Interested in that too, surely it'd break down and crumble over time?

 

[White Room]

I'll stick to using spf.....

 

[JamesHardie]

HardieBacker is fastened to the subfloor with nails or screws, not exactly with the adhesive. The intent of the cement based adhesive is not to make the board stick to the subfloor, but rather to be used as merely a gap filler to minimize the imperfections of the floor. The installation system has been rigously tested and HardieBacker performs best when all of the steps in the installation guide are followed.

 

[White Room]

HardieBacker is fastened to the subfloor with nails or screws, not exactly with the adhesive. The intent of the cement based adhesive is not to make the board stick to the subfloor, but rather to be used as merely a gap filler to minimize the imperfections of the floor. The installation system has been rigously tested and HardieBacker performs best when all of the steps in the installation guide are followed.

Surprised of the use of nails though.....

 

[jimthetiler]

What ever you put on a wooden floor,its still a wooden floor and will flex and move and expand and shrink with the building.Tell your tiler he can still use his rubber adhesive once he has laid the backing boards that way you will have a fighting chance of the floor lasting a while,and another thing ,the smaller the tiles the better.

 

[jason67]

Thanks gentlemen for you advice.

Sounds like the Hardibacker boards should be used.

One thing I’m a little confused by; The Hardibacker instructions state “Apply a gap filling bed of non-flexible tile adhesive to the subfloor using a 6mm notched trowel.” Does this mean, in my case, that the non-flexible tile adhesive should be applied direct to the P5 chipboard flooring?

If it does, then I don’t understand why you can’t apply flexible adhesive directly to the P5 chipboard flooring and fix the tiles directly to the P5 chipboard flooring?

 

[Ian]

Thanks gentlemen for you advice.

Sounds like the Hardibacker boards should be used.

One thing I’m a little confused by; The Hardibacker instructions state “Apply a gap filling bed of non-flexible tile adhesive to the subfloor using a 6mm notched trowel.” Does this mean, in my case, that the non-flexible tile adhesive should be applied direct to the P5 chipboard flooring?

If it does, then I don’t understand why you can’t apply flexible adhesive directly to the P5 chipboard flooring and fix the tiles directly to the P5 chipboard flooring?

The hardie boards are screwed down, the tiles won't be. A cement board is a far more stable substrate to tile to, it does not swell or warp if it comes into contact with moisture, chipboard will.

 

[Rookery]

I always use RSF + screws to overboard a timber floor. I cant see why a non-flexy is recommended over a flexy adhesive.
However, taking the instruction that the adhesive is a 'gap filler' i.e. for cupped t & g floorboards, would it not then be ok to merely screw the Hardie down onto a perfectly flat chipboard floor with no addy at all? Come Mr Hardie we want to know.

 

[Rookery]

HardieBacker is a Cement based board that provides a suitable surface to tile on to. Unlike wood, it does not expand and contract with exposure to water. Attached is a copy of the HardieBacker installation instructions.

If you are looking for an additional document to source take a look at this NHBC Standards – Section 8, Part 3, Para D4

TILES ON WOOD-BASED SUBSTRATE
The floor should be designed to take the additional loads of tiles and any other materials (e.g. overlays). Tiles should be suitable for laying over a timber base.
The floor decking should be: chipboard floor decking overlaid with minimum 10mm plywood suitable for exterior conditions and fixed as above, or proprietary separating/de-coupling layers, tile backer boards or tile bedding reinforcement sheets used in accordance with the manufacturer's recommendations.

I hope this helps

So NHBC standards are lower than BS5385. No wonder todays houses are such crap.

 

[kilty55]

still plenty people who tile to chipboard , after seeing so many failed jobs on chipboard some of which will take time to fail i wouldnt advise tiling onto it definately go the cement sheet route aquapanel for me

 

[widler]

i agree use hardi,its great stuff .

 

[charlie1]

HardieBacker is fastened to the subfloor with nails or screws, not exactly with the adhesive. The intent of the cement based adhesive is not to make the board stick to the subfloor, but rather to be used as merely a gap filler to minimize the imperfections of the floor. The installation system has been rigously tested and HardieBacker performs best when all of the steps in the installation guide are followed.

i can see why it would perform better using non flexible adhesive, the combination of the hardie and the adhesive becomes one solid slab rather than hardie with a flexible bed which could theoretically have slight movement.

 

[jason67]

I will definitely be using Hardibacker boards

Picking up on what Rookery said; as Hardibacker recommend laying the boards on non flexible adhesive for GAP FILLING purposes only, and seeing as my chipboard flooring is dead flat, then should my boards just be screwed down without using adhesive?

 

[Gazzer]

You can only go with what the manufacturer states, if you dont then you are on your own should anything happen.

 

[Ian]

Should Hardibacker boards be used or not?

I will definitely be using Hardibacker boards

Picking up on what Rookery said; as Hardibacker recommend laying the boards on non flexible adhesive for GAP FILLING purposes only, and seeing as my chipboard flooring is dead flat, then should my boards just be screwed down without using adhesive?

I'd still stick them, it's good practice IMO

 

[Ceramico tiling]

I don't believe the guy has been tiling long if he says he can tile onto chipboard.

 

[JamesHardie]

@Whitebeam While it is most common for people to use screws, nails are also warranted. A 25mm-30mm galvanized roofing nail is just fine. At the end of the day it's a matter of preference.

@Jason If you search around on some of the chipboard manufactures websites, you'll see many of them state that tiles should not be applied directly to the board.

An example would be Steico UK, they directly state "Please note the fixing of ceramic tiles directly to the board should be avoided and an inert barrier should be placed between board and tiles."

If you ask your tiler to follow all of the installation steps provided in the HardieBacker Installation Guide, you can be confident that you will have a floor that will last.

 

[kctiling]

according to james Hardie a 6mm panel should be used on a masonry wall.Has anyone done this as I thought you should use 12mm

 

[kctiling]

Use a backer board defo chip board will break after a while

 

[jason67]

Gentleman

I didn’t want to completely dismiss my original tiler, even though his idea was to tile directly to onto my P5 chipboard, as he had previously tiled for me and friends in the past with excellent results, so I did one last bit of research and discovered Norcros Direct to Wood:

This is the product my original tiler wants to use.

I contacted Norcros Adhesives, and asked them to confirm, “Can I tile directly onto P5 chipboard flooring with Norcros Direct to Wood”?

This was their reply:

Good Morning Jason

I can confirm that Norcros Tile Direct to Wood is suitable for tiling directly onto P5 flooring grade chipboard subject to the board being securely fixed and deflection-free.

Please find attached a copy of our ‘How to’ and product data sheets for this product.

I trust this is satisfactory.

View attachment 52347View attachment 52346

Any thoughts on this product?

 

[The Legend; Phil Hobson RIP]

Overboard with Hardie imo, the key word in Norcross or any other rubber crumb adhesive is deflection free. I would never tile directly to any type of chipboard, just not a good substrate.

 

[Martyn Leeds]

Hey, you can also go to B&Q and buy a tub of Unibond 'Tile on Wooden Floors', its adhesive and grout all in one and eliminates the need to overboard... or take the advice thats been given by nearly 100% of the replies?