Hi all,

New to this forum and an amateur DIY'r.

Got a problem I'm hoping that someone can help me with as I'm pulling my hair out.

Moved into a new build house last April with a small bathroom (with no window and an extractor fan) and dodgy lino.

Decided to remove the lino and tile the floor instead. Pulled up the lino to find MDF (?) panels stapeled to the floor which had developed black mould from water leakig under (the seal was split around the bottom of the bath).

Ripped up the panels to expose a smooth green plasterboard below.

Anyway....bought some 33x33cm ceramic tiles from Homebase and cut to size to fill the whole area.

Then bought Evo-stik Tile-a-Floor Flexible Adhesive & Grout for Wooden Floors, amd Evo-stik Waterproof PVA as directed on the back of the Adhesive tub.

Brushed on the PVA as directed at 1PVA:4water and waited till dry. Then used a floor spreader to put the adhesive/grout down and twisted the tiles into place (I've read since that a lot of people don't recommended PVA)

That was on Saturday - trouble is it's just not setting. just lifted up a tile and although a cm of the grout around the edge of the tile had set, beneath the tile, it's exactly the same as when I put it down 4 days ago. I can't work out where I've gone wrong.

Sorry for rambling but desperate for help as I've spent a fortune on everything so far and not sure what to do now.

Any help would be much appreciated!

Oh dear Superfuel.. that's a bit of a pickle you're in there...

PVA is an absolute no-no as you have now since read. Some of the experienced and professional members on here will no doubt have some more technical expertise to share with you about PVA, the adhesive used and your floor/substrate, but you probably won't see much response on here until after 5.

My initial reaction is to pull the tiles up now, whilst the adhesive is still soft, and seeing if you can scrape the adhesive off so that you can save them and not have to bin them.

So take a or have a well earned and don't panic... you've come to the right place

Oh and to the best tiling forum in the world

Thanks for the response!

I have indeed pulled up the tiles and cleaned all the adhesive of in the bath this afternoon and scraped the floor clean.

The jobs on hold now though as I haven't got a clue where to go from here, although I want to get it sorted as we still have to use the bathroom in it's current state (with the old lino back down with no seal and towels on the floor below the bath for a quick shower)

The girlfriends getting pretty annoyed now too as I've been over a week doing this as I'm no nearer to finishing.

Fingers crossed someone can help me!

Welcome Superfuel.

My first thoughts...........

I'm slightly confused as to your floor substrate. Plasterboard is not a stable or strong enough product for flooring, are you sure it's not "green" chipboard?
How is the floor substrate fixed, screwed or nailed?
Is this a ground floor or first / second?

Personally, I refuse to go anywhere near a ready mixed floor adhesive, no matter what the DIY sheds say, and will always use a flexible cement based product.

Let's identify what your floor is first, then identify the correct adhesive and fixing process.

my mistake - it's green chipboard, and the bathrooms on the 2nd floor.

Is that where i've gone wrong?

Superfuel to the forum, I am relatively new here myself.
As to the problems you are having.
I haven't used evo-stic adhesive before, but is it possible that it was out of date this could be the reason it hasn't set? I never use PVA I always use an acrylic primer, However you did follow the manufacturers reccomendation.
Also you say you removed MDF which was on the floor and exposed plasterboard! The plasterboard is probably there for fire reasons and or sound proofing, Im sure someone else will be able to give the exact answer. Did you put anything down on the floor or did you just tile on top of the plasterboard?
What I would have done is put a good quality tile backer board down on the floor on top of the plasterboard, such as hardi backer board, and then i would have tiled on top of that with a good brand of flexible tile adhesive like a Bal make. I never used the ready tubbed stuff for floors, I always use the bagged stuff you mix your self.
I hope this may help you but i am sure yoou will get loads of more questions and answers shortly.

Okay, is the chipboard screwed or nailed? If it's nailed then it needs to be screwed securely. Once you've ensured that it is screwed properly have a little jump up and down to identify if there is any "bounce" in the floor. If no bounce, then I would recommend fixing 6mm cement boards over the chipboard, this will provide you a much better and adhesive friendly tile substrate. If there is bounce, then screw 12/18mm ply to take out the flex and give a better substrate.

You glue and screw cement boards and just screw the ply, there are plenty of posts on here regarding the fixing process for each, but don't hesitate to ask if you need more info.

So, substrate sorted!

I need to know whether cement boards or ply as the fixing process and adhesive will vary a little? Let me know which way you want to go.

If you want to tile directly onto the chipboard, this can be done, but it is not recommended and you will need a highly flexible (more expensive) adhesive such as Mapei Keraquick with latex, BAL Fastflex or Ardex 7001.

Thanks - The chipboard seems to be nailed down but is solid with no bounce. It's the same flooring that run throughout the whole top floor of the house (underneath the carpets).

I'll see if I can get hold of some cement boards and will put those down - once I've got that sorted I'll post an update and go from there.

I still don't know why the adhesive/grout wasn't setting though - if I go down the substrate route and use the corrent adhesive/grout, will this defintley solve the problem do you think? (The last tub of adhevise cost £25 so I'm keen to get this right first time....well, second time really).

This is turning out to be a lot more difficult (and expensive) than I first thought!

On another note, I've just read that you need special equipment to cut a cement board and I need to get it to go round the toilet and sink too but can use the old lino as a template (lifting them up isn't really an option).

Will I end up spending a fortune on the equipment to do the job? (I've bought a £40 electric tile saw already and have the usual hack saw and wood saw in my tool box)

Would an alternative option be cheaper as I was doing the job myself primarily too save money (approx 2.5 metre square space and I've spent over £120 already and loads of time).

Obviously my main concern is getting the job done right, but I still need to watch the cash!

It is difficult to say why the ready mix stuff didn't set. Could be one of many reasons....

1. Past it's useable life (check dates printed on tub somewhere)
2. It may say it is okay for wood, but does it say "moisture resistant chipboard"
3. Did you disturb the tiles within the "curing" time? i.e. walk on them within 24 hrs of fixing?


As long as you follow our advice and recommendations you will not have any problems this time round.

One last question for now, do you have a Tile Giant near you? You can check store locations here......Tile Giant.

If not, can you advice what tile shops or builders merchants are local to you, please? It will help us to advise the correct adhesives etc..

Keep smiling, you've found the forum so you're now more than half way to resolving your issues .

Originally Posted by superfuel

On another note, I've just read that you need special equipment to cut a cement board and I need to get it to go round the toilet and sink too but can use the old lino as a template (lifting them up isn't really an option).

Will I end up spending a fortune on the equipment to do the job? (I've bought a £40 electric tile saw already and have the usual hack saw and wood saw in my tool box)

Would an alternative option be cheaper as I was doing the job myself primarily too save money (approx 2.5 metre square space and I've spent over £120 already and loads of time).

Obviously my main concern is getting the job done right, but I still need to watch the cash!

Before you do anything, you must replace the nails with screws. Nails can work loose and cause your tiling to fail.

Cement boards are fairly easy to cut, they just blunt your blades pretty quick. If you have a jig saw, that will make cutting around the potware easy.

The floor is small enough that you can tile directly onto the chipboard if you want; you shouldn't experience problems provided that it is definitely solid with NO FLEXING, and you use the correct materials (not your DIY stuff).

I look forward to hearing your choice.......

FYI - This is what I used which didn't set for some reason;

Home Building Supplies | Evo-Stik Large Grey Floor Tile Adhesive & Grout For Wooden Floors | Building Supplies | Tile Adhesives & Grouts | Choiceful.com

It specifically says on the back that it's for use with chipboard.

Couldn't find a 'best before' date anywhere on the tub either.

Thanks SF.

I may have missed a trick here , so apologies.....But, the floor tiles, whilst they say ceramic, could they be a vitrified ceramic by any chance? Did they take a bit of force to cut and were they quite brittle?

Vitrified tiles are fired at much higher temperatures (much the same as porcelain) which reduces moisture in the tile. Porcelain and highly vitrified tiles should be fixed with adhesive that is designed for use with said tiles. It is possible that the adhesive is not suitable for use with your tiles, as it is only for ceramic tiles, i.e. not vitrified, and that may be why it has not worked .

I, personally, still wouldn't use that stuff, no matter what the substrate though.

LOL! Just read the description for that adhesive....

. Waterproof and frost resistant.
· Dries charcoal grey.
· Ideal for interior use.

How many times have you needed an adhesive that is frost resistant indoors? And as for waterproof , not a chance!

Just checked and theres a tile giant just 18 miles from me

I'm actually going to be 5 min's drive from there tommorow as I'm over at the gf's parents.

Any chance you could let me know what I would need to buy in order to stick the tiles down to the chipboard directly and ensure it's waterproof?

If I could pick the stuff up tomorrow it would save me a trip (and much hair pulling out too).

I'd go over the mrc with hardiebacker and use a powdered single part flexible adhesive, making sure substrate is suitably screwed down and deflection free, also use a flexible grout. Belt and braces approachOh! and chuck the PVA

First thing to note, no adhesive will be waterproof!
If you want waterproof, then you will need epoxy (my advice is to not go there) grout.

However, if you use the correct materials then you won't have any issues unless you soak your floor every day (i.e. use it as a shower tray ). In which case it needs tile backer boards or tanking.

Please answer this question so that I can advise materials....
Are you tiling directly onto the chipboard or onto tile backer (cement boards)?

Thanks for the tip!

These are the tiles I'm using: Cuba Floor Tile - 33 x 33cm - Dark Grey - Pk size 9 from Homebase.co.uk

Nothing on the box or website about what kind of ceramic they are.

In terms of cutting them, they were pretty tough to cut through (I used an electric wet saw) but brittle in the sense that I accidentaly trod on one when it was on the carpet and it broke in half.

Is it worth taking one of the tiles with me to Tile Giant to see what they suggest?

Are you tiling directly onto the chipboard or onto tile backer (cement boards)?
If I can tile straight onto the chipboard then I will (to save time and money), but if cement boards are recommended then I'll go down that route.

You guys are the experts so I'm really looking for your recommendation

From the picture, they appear to be just standard glazed ceramic. The substrate is more important info as that will determine the adhesive you will need. Still, take a tile with you, it can't do any harm

As per Doug, your best bet is tile backer boards, Mapei Keraquick (rapid set) or Keraflex (standard set) and use Mapei Ultracolour grout. You will get all that from Tile Giant and mention the forum as they should look after you.

If you insist on tiling onto the chipboard then change the adhesive to Mapei Keraquick with latex and get some primer G to prime the chipboard with. Use Mapei Ultracolour grout and job will be a good'un.

Cement boards are the best route, and it won't hurt if you take a tile with you as the store may be able to make a recommendation to save you some dollars.

Good luck

Originally Posted by Captain Slow

As per Doug, your best bet is tile backer boards, Mapei Keraquick (rapid set) or Keraflex (standard set) and use Mapei Ultracolour grout. You will get all that from Tile Giant and mention the forum as they should look after you.

If you insist on tiling onto the chipboard then change the adhesive to Mapei Keraquick with latex and get some primer G to prime the chipboard with. Use Mapei Ultracolour grout and job will be a good'un.

Cement boards are the best route, and it won't hurt if you take a tile with you as the store may be able to make a recommendation to save you some dollars.

Good luck

Daz, would you recommend getting rid of the dried PVA layer before priming?

Liz

That's a very good point Liz, if going directly onto the chipboard. Best to go over the floor with a belt sander or 60 grit to remove "the devils spit".

Cement boards are deffo the way forward here, I think!

Don't know the answer to this one but have a question. Does anyone know if tubbed adhesive has a retarder in it. I know with Mortars the retarder is sucked into the bricks which causes the mortar to go off. If the addy os retarded it might work on the same prinicpal with the substrate hence not work on moisture resistant board.

As I say though it's just a theory.

but if it's dispersion, as wall tubbed addy, it will require air/porous substrate to help it set, whereas a cementitious addy would set (wether it would bond to mrc I don't know tho!)

Thats why I don't use tubbed adhesive

if you ar egoing to tile directly on to your chip board you WILL need to screw in down even if there is no movement now there will be in the future (speaking as one who lives in a new'ish build) but before you do this take a sander to the floor to remove the PVA and replace with a suitable primer and a powered flexible adhesive not sure what brands tile giant sell but if you ask the lads in there they should advice you on whats best.
chris