Who glues their cement board?

[Stef]

for me its always glue and screws. and screws have to be from hardie they are strong imho

Try Turbo Gold screws from ScrewFix 25mm,
They drive great through Hardie & will be a damn site cheaper.

 

[JamesHardie]

Always use a cement based tile adhesive between the subfloor and the backer. It's a gap filling bed of adhesive. We recommend doing it with every install, why risk it?

 

[Rookery]

I always glue and screw. However, Hardie say the adhesive is to fill voids (ie in cupped s/w t&g) but I've previously asked the question 'why glue when you're overboarding perfectly flat chipboard' and I've yet to get an answer from them.

Well come on, Hardie Man, please reply.

 

[widler]

Well come on, Hardie Man, please reply.

He has, above

 

[Gazzer]

Well come on, Hardie Man, please reply.

He has, above

:lol:

 

[Rookery]

Really? So what if there are no gaps to fill, ie on a perfectly flat V313 chipboard floor. Like I originally asked.

 

[The Legend; Phil Hobson RIP]

I would still glue and screw, belt and braces.

 

[Gazzer]

Whats the big deal, its not going to break the bank or even slow you down !

 

[JamesHardie]

Rookery

In theory you are right, if there were absolutely no gaps with a perfectly flat surface the No. However, through the R&D we have done over the last 20 years we know that is not the case. There are imperfections that we can't easily see. The slightest gap can cause tile to crack. Using the adhesive may seem like overkill, but for anyone who has ever had tile crack on a jobsite, probably wishes they could have done anything to prevent it. For cement board, using the tile adhesive is that sort of prevention.

 

[Stef]

Just putting my 2 bobs worth in,
I tiled half of a hall, the other half was supposed to get carpet fitted, it was finished on a cut, 3 quarters of a tile, then the outlaws decided they wanted the whole hall tiled so I had to rip up 2 cuts.
I know Hardie state the addys only for gap filling but believe me that Hardie didn't want to budge, it was stuck solid to the floor boards with the addy, it came up in layers.
If overlaying with Hardie I don't care how flat the substrate is I will always glue it down with adhesive.
I always use flexible adhesive even though you don't have to, it just sits better in my head that you are going over wood..

 

[widler]

To be fair, ive said to to sir ramic before, NMP use Silicon like glue, which will cause slight gaps underneath as its not spread all over like addy.
And ive also said that spreading addy does seem to add rigidity to a wood surface(not stop bounce)although i have done it with no addy or glue to a flat wood surface before with no problems,we never did it with ply did we ?

 

[Stef]

To be fair, ive said to to sir ramic before, NMP use Silicon like glue, which will cause slight gaps underneath as its not spread all over like addy.
And ive also said that spreading addy does seem to add rigidity to a wood surface(not stop bounce)although i have done it with no addy or glue to a flat wood surface before with no problems,we never did it with ply did we ?

I know what you mean about the ply, God I used to fix to 6mm ply, would I do it now? Not a chance, well not on my own jobs anyway.
I just don't see the point in taking the risk in a floor failure for the sake of a couple of quid.
6mm trowel spreading addy, a 20kg bag would fix a fair amount of Hardie boards.

 

[JamesHardie]

Well said Stef.

 

[Rossymcg]

I nip in b&q/wickes if I'm passing and stock up on any split bags they have for this very method, takes maybe half an hour to mix up spread and clean up to glue down boards, it seems a no brainer to me,

 

[Rookery]

Whats the big deal, its not going to break the bank or even slow you down !

Its not a big deal cos if you had read my post you'll see I always glue & screw. I just wanted the precise definition from the manufacturer, not merely the opinion of others. He has now confirmed in post no.39 what I suspected that on a flat chipboard floor, it is not necessary to glue, in theory. Thats all I wanted to know.