I will tile over moisture resistant t&g chipboard. They are screwed to 70 mm joists fixed on solid concrete floor with kingspan in between. Originaly this was prepered for carpet but we have change our minds.I have tiles and butech tile on wood flexible adchesive in buckets. Have been told diferent things how to do it. Any sugestions ( ply, mats,primers)? Thanks

You don't say what tiles your using, I would over ply with 12mm or even 18mm, also check the spacings between each joist 400mm should be the max. Have'nt used that adhesive so cant help with that brand, I would use a single part flexible cement powdered one.

Check on the tub if it needs priming as well

Originally Posted by whitebeam

You don't say what tiles your using, I would over ply with 12mm or even 18mm, also check the spacings between each joist 400mm should be the max. Have'nt used that adhesive so cant help with that brand, I would use a single part flexible cement powdered one.

Check on the tub if it needs priming as well

It's good gear. I used it on 18mm ply and the instructions said to prime with butech acrylic primer prior to tiling. The addy is a 2 part and very flexible and works well on wood substrates. Be aware that it tends to go off pretty quick, though, so if you are not a fast tiler I would mix it up in small batches.

Thanks,
I will use wood floor like tiles from porcelanosa, wonder if is realy necesary to overlay with such a thick ply ,my joists are 35cm apart and realy rock solid fix. Is chipboard not suitable for tiling becouse is not strong enaugh or there is something else wrong with it?

if thickness is an issue then overbord with "NO MORE PLY" 6mm thick waterproof when treated and strength equivelent of 18mm ply once down you can use a single part flexi addy rather than a two part. personally i dont like the butec gear but its everyone to their own as long as it does what it says way hey.

pyrakanta you need to activate your account...you will have an email sent to you to link you back to the forums to authorise your email address..

I will send you new activation codes out now..

Originally Posted by pyrakanta

Thanks,
I will use wood floor like tiles from porcelanosa, wonder if is realy necesary to overlay with such a thick ply ,my joists are 35cm apart and realy rock solid fix. Is chipboard not suitable for tiling becouse is not strong enaugh or there is something else wrong with it?

It is not that strong no, but if it gets damp or wet enough then it will still swell. It is only moisture resistant.

Crack isolation mat 3mm thick you simply staple it to the chipboard

Originally Posted by jdcarling

Crack isolation mat 3mm thick you simply staple it to the chipboard

Which particular mat are you referring to? Don't know if I would fancy may tiles only being held to the substrate with staples!!

Originally Posted by smurf21

if thickness is an issue then overbord with "NO MORE PLY" 6mm thick waterproof when treated and strength equivelent of 18mm ply once down you can use a single part flexi addy rather than a two part. personally i dont like the butec gear but its everyone to their own as long as it does what it says way hey.

You got documantary evidence to support that Smurf as I would be really interested in seeing it if possible?

sorry for this delayed message, i have only just found this thread! hope the statement from the guys who make the stuff helps.

No More Ply has now got full BBA accreditation. BBA are the British Board of Agreement who give full technical approval for construction products. Their testing and certification concludes that No More Ply has been assessed by the BBA as being fit for its intended purpose provided it is installed as set out by No More Ply. Its intended purpose is for over boarding floorboards instead of plywood because plywood is not a guaranteed tile backer board. The BBA assessment and certification really overrides anything that any adhesive manufacturer or any other board manufacturer may conclude, and The BBA certificate also proves that the board meets all British Building Standards and Regulations.

If used as described then it is a very good product.

BBA says that no more ply is fit for intended purpose, the intended purpose is to replace 15mm ply.

Here is a link to the certificate. Not sure it actually mentions being a full "strength for strength replacement" for 15mm ply as it doesn't say this but it does make interesting reading.

http://www.bbacerts.co.uk/PDF/4575PS1i1_web.pdf

Think that will stop a few doubters.
i think that tilers should embrace products that are designed to help.
sold these now for a good few years and we have NEVER had any come backs
happy tiling

Originally Posted by leesimpkin

Think that will stop a few doubters.
i think that tilers should embrace products that are designed to help.
sold these now for a good few years and we have NEVER had any come backs
happy tiling

Not sure it will stop the doubters, me included as it doesn't stipulate that it adds strength to the floor like 15mm ply does, and neither does the NMP data sheet either. Their data sheet only says that it replaces the ply as recommended by BS (in a round about way), nothing about adding strength. I personally would much prefer to see hard evidence that it actually does strengthen the floor before I would recommend it to my customers.

Hardie is a similar product and they specify that timber floors must not deflect by more than a certain amount, and they give a formula for that. I would be much happier if NMP did the same, but they don't.

Again these are my own personal opinions and not that of Tilersforums.co.uk

personally if the floor is solid i'd opt for the ditra matting and single part flex sticky. worked for me for years now and no probs

to be honest, the name alone puts me off, no more ply, it just sounds "gimmicky", I know that we all have to embrace new products, but they need to be well researched/tested prior to being unleashed into the market,and at least give some kind of performance data. I'd be surprised if this product is still around in another 5 years

Let's face it - 18mm ply overlay just isn't an option 70% of the time in the real world.
People don't want ridiculous steps.
People don't want to buy new doors.
People want to be able to open their upvc doors.
People want to be able to fit their white goods back under their kitchen worktops etc.....

I think people who have not used a product aren't in a position to have an informed opinion.
It's all about common sense - if you use NMP correctly then you will know before you tile that the substrate is solid and you will be fine.
I overlay with ply when possible, but often it is just not viable for the reasons above and the customer will then probably go with someone who just lays it straight onto chipboard/floor boards and get a cheap botch job.

I know I defend NMP alot, but I promise you this - if I were to ever have a failure or I felt NMP was not fit for purpose I would be the first to tell you all about it.

Originally Posted by macten

Let's face it - 18mm ply overlay just isn't an option 70% of the time in the real world.
People don't want ridiculous steps.
People don't want to buy new doors.
People want to be able to open their upvc doors.
People want to be able to fit their white goods back under their kitchen worktops etc.....

I think people who have not used a product aren't in a position to have an informed opinion.
It's all about common sense - if you use NMP correctly then you will know before you tile that the substrate is solid and you will be fine.
I overlay with ply when possible, but often it is just not viable for the reasons above and the customer will then probably go with someone who just lays it straight onto chipboard/floor boards and get a cheap botch job.

I know I defend NMP alot, but I promise you this - if I were to ever have a failure or I felt NMP was not fit for purpose I would be the first to tell you all about it.

Hope you don't think I have been derogatory about NMP in my posts. I am not denagrating the product as a backerboard, just the claims that is a strength replacement for 15mm ply. It may well be so, but as yet, no one or any "approving" agency has clarified that it is so. I am unable to actually try out the product myself as it is not available in my area so I am unable to assess it an make my own decision as to it's suitabilitly. This is where the external testing would be of much value as then people like myself would have much more confidence in ordering a pallet load of the stuff and getting it delivered.

I think it worthwhile you ordered a pallet load Grumpy. The number of jobs I would miss out on were it not for this product is very significant. NMP has been around for quite a while now yet I have never heard of a single failure with the product. I think that shows suitability and longevity alone. But the ultimate test is just trying it out on a job and jumping around on it afterwards and you will have no doubts to its suitability.

Does NMP when used correctly give the same strength as 15mm ply? I don't know but if I had to guess I would say not.
Is it strong enough when used properly with todays Polymer-modified adhesives - absolutely. If I'm ever in doubt I use a 2 part.
Is NMP a better substrate to tile onto compared with ply - absolutely in every way.

I can get you a good deal on a pallet load Grumpy if you ever decide to turn to the darkside!

Thanks for the offer Macten, I will consider it if and when the time comes. Currently I tend to use 6mm hardie, or if circumstances allow, Wedi board, but only if the floor ahs no deflection.