All tiles have not stuck

[Gazzatile]

Having spoken to a timber supplier he tells me that even exterior ply is not waterproof just the adhesive holding the sheets together so this can mean the tiled surface can swell from the water in the adhesive and this will not help keeping tiles on to the board

 

[bitter&twisted]

I think the main problem was you put the adhesive on the tile not the floor

 

[Wylie]

I think the main problem was you put the adhesive on the tile not the floor

I would go with that and if there was any dust on the floor and the addy to thick:yikes:

 

[G&B Bath&Tile]

Great insight from everyone. My thoughts to look at,
1: Will the board absorb any water? Or does it bead up?
2: Sounds like the addy/thinset dried to fast. Mixture of addy was to dry, or board was to dry. (sucks the moisture from your addy/thinset) in which I reccomend slightly wetting down the board (I usually do this with a wet sponge removing dust anyways).
I really do not see the board thickness affecting the bond this early in the game. Hope this helps

Brett

 

[aflemi]

I would go with that and if there was any dust on the floor and the addy to thick:yikes:

I'm jumping on this thread a bit as I am about to lay 10,, rough-faced porcelain floor tiles onto 12m ply over floorboards (I have sealed the underside with SBR). In applying wall tiles first the ply has got dusty + a few splashes of wall addy etc. Is it ok to give it a good clean with hot water and let it dry fully??

 

[G&B Bath&Tile]

Not sure if I'm supposed to reply to this or if it's a new thread, but anyway's. sorry if not

I would do just that, I always recommend and do a good vaccuming and or wet sponging to any of my backer. wetting the ply a little bit will help for the ply to not suck your moisture to fast from the addy/thinset.

Of course this goes against my beliefs of laying ANY floor tiles on wood... ;-)


Brett

 

[sheene222]

thanks guy's as a newbie and trying my hand at tiling after being made redundant in the print trade and having just spent a bit of time on a tiling course the advice here is great...thanks again

 

[ash9112000]

Hi, I know its probably a bit late but I would like to give my opinion.
Its doubtful that the adhesive was to blame, too thick, too thin, too much addy not enough addy etc. Most adhesives esp bal stick like sh#t to a blanket, sometimes even under the worst conditions. It sounds to me like the problem was too consistent for it to be a slight error due to bad workmanship. There had to be something on the ply that caused the tile adhesive to either react with a substance on the board, or simply the substance was so, that the adhesive was intolerant to it. Either way, if the ply had been only slightly porous it would have been enough to create a key, which would have meant that it would have stuck for longer than a week at least. The wbp glues are mainly melamine and phelonic, some are moisture resistant whilst some are regarded as permanent. If the wbp glue had absorbed itself into the surface of the ply it would have created a barrier against the tile adhesive. The absorption of the tile adhesive into the ply would have been next to nothing. Hence the reason why its stuck well to the tile and not the ply. I hope this gives at least some resolve.

 

[Superally]

I'm going along with "something on the ply" The BAL man tool one look at it and new something was wrong with the ply. Re did the job with fast flex. A proper learning experience!!

 

[grumpygrouter]

I'm going along with "something on the ply" The BAL man tool one look at it and new something was wrong with the ply. Re did the job with fast flex. A proper learning experience!!

Fast Flex...nice!??!!!?

 

[mike walker]

Like I keep saying men forget ply and use backer board its waeterproof and tile stick it it far better

 

[grumpygrouter]

Like I keep saying men forget ply and use backer board its waeterproof and tile stick it it far better

No good for adding strength to a floor though......

 

[mike walker]

No good for adding strength to a floor though......

have to disagree there Grumpy they do add strength but strength is rarely required its a good tiling surface thats needed

 

[G&B Bath&Tile]

1/2" hardi backer thinsetted and screwed sure does add strength. It seems like it extremely common for you pro tilers over the big pond to lay alot of tile directly over ply. Please take no offence but I know of no tile setters here that willingly choose to lay on ply for floor tiles. I mean we know "you can" set tile over most any secure substrate, but the only professional way is to use "a true backer" "membrame" or concrete. Wonder why it seems so commonplace over there, or is it?

Brett

 

[grumpygrouter]

have to disagree there Grumpy they do add strength but strength is rarely required its a good tiling surface thats needed

I have not seen one backerboard manufacturer that has said their product adds strength to a floor, but I an happy to be corrected. All the information I have seen states that the floor "should be adequately braced to eliminate movement". Hardie even go so far as giving a calculation to see how much deflection is acceptable.

If you have documantation that shows otherwise, please post it on here for us all to see. Wouldn't half make life easier if that was the case.

 

[mike walker]

1/2" hardi backer thinsetted and screwed sure does add strength. It seems like it extremely common for you pro tilers over the big pond to lay alot of tile directly over ply. Please take no offence but I know of no tile setters here that willingly choose to lay on ply for floor tiles. I mean we know "you can" set tile over most any secure substrate, but the only professional way is to use "a true backer" "membrame" or concrete. Wonder why it seems so commonplace over there, or is it?

Brett

Hi Brett it is quite common here to tile on ply but for me its backerboard all the time now

 

[G&B Bath&Tile]

HardieBacker™ cement board is recognized as an interior substrate according to the following:

• National Evaluation Service (NES), Inc., Report No. NER-405 (BOCA, ICBO, SBCCI)
• City of Los Angeles, Research Report No. 24862
• City of New York MEA number 223-93M
• HUD Materials Releases 1263d and 1268c
• Tile Council of North America handbook

Flexural Strength

Based on typical Equilibrium Moisture Content: 2100 psi when tested in accordance with ASTM test method C1185.

1/2" Hardi backer laminated (thinset + screwed) to 3/4" T&G (advantech) is pretty much bullet proof ;-)



Brett

 

[G&B Bath&Tile]

Thanks Mike Walker,
I can't figure out how to thank you like your supposed to... sorry

Brett

 

[grumpygrouter]

HardieBacker™ cement board is recognized as an interior substrate according to the following:

• National Evaluation Service (NES), Inc., Report No. NER-405 (BOCA, ICBO, SBCCI)
• City of Los Angeles, Research Report No. 24862
• City of New York MEA number 223-93M
• HUD Materials Releases 1263d and 1268c
• Tile Council of North America handbook

Flexural Strength

Based on typical Equilibrium Moisture Content: 2100 psi when tested in accordance with ASTM test method C1185.

1/2" Hardi backer laminated (thinset + screwed) to 3/4" T&G (advantech) is pretty much bullet proof ;-)



Brett

Thanks for the info Brett. Interestingly the document you link to for Los Angeles states that the board must be adhered and screwed to a minimum of 15.8mm t&g ply and also gives the deflection calc L/360 being the maximum allowed. Also, here in the UK, Hardiebacker 250 is specified for floor use, not 500 as this is specified for walls. Maybe you have a slightly different product spec over your way to what we have here. it is not normal practice here in the UK to specify plywood as a subfloor. Mostly we use 18 or 22mm t&g chipboard. Thereby lies the problem we think!

We have even asked the question of Hardie UK on these forums and was given the answer that the floor must have sufficient inherent strength as the board itself adds very little.

 

[Superally]

What in an ideal no cost issue world what would be the perfect floor to tile onto assuming you walked in and saw the floor joists i.e. no flooring whatsoever. After my experience it would be at least 18mm ply, 25mm ideally covered with hardibacker 250 then tiled....ignoring underfloor heating? His would also help with the build up of height.

 

[brian c]

its really up to the person paying for it then SUPERALLY.Dont see any reason why you cant ply out with 22mm ply and add extra noggings,then imo there is no need for backerboards(extra expense)

 

[Tunni]

For what it's worth, I've used 6mm ply in my own home. I'm not a pro tiler but a very experienced carpenter. (in fact good on you guys I bloody hate tiling..only slightly less than grouting mind!! LOL!) I have tiled onto 6mm ply using flexible ready mix adhesive (can't remember which one - but it sets with an almost rubber like consistency. Never had a problem with the tiles and they have been down 15 years.

Regarding this ready mixed stuff vs bag gear, I did have some 'pro' tilers do a job for me once using bag adhesive on a wood floor. They said it was flexible and had used an additive. I harboured a concern when finding an overspill of set adhesive and tested it's 'flex' ..It snapped like glass.

I ended up ripping out the whole lot a year or so later as some tiles had cracked and others came loose. Absolutle nightmare of a job. Ended up doing it myself with the tub gear (had to lay a new wood floor as well -and had no problems since)

I still worry about the 'flexible' bag stuff for use on wood floors as I'm doing my own wet room now and will be using the stuff as all you pros reccommend it! (As a precaution I'm gonna use ditra matting)

Tunni

 

[beanz]

Double post, sorry.

 

[beanz]

(had to lay a new wood floor as well -and had no problems since)

Could it be that the original floor was to blame for the cracked tiles (ie.deflection), not the addy?

 

[Dan]

Just bumping some of the older popular (sometimes not so popular) threads. Probably wont be current discussion these days but I just need to do it. So just ignore the thread if it's not current for you.